volume 1, issue 3 of tropical plant research
DESCRIPTION
1. Phenology, Growth and Survival of Vatica lanceaefolia Bl. A Critically Endangered Tree Species.2. Pogonatum perichaetiale subsp thomsonii (Mitt.) Hyvönen - An uncommon species from western Himalaya.3. Species composition and structure of Sal (Shorea robusta Gaertn. f.) forests along disturbance gradients of Western Assam, Northeast India.4. Comparative evaluation of nutritional, biochemical and enzymatic properties of the mycelium of two Pleurotus species.5. Study on relationship and selection index in chickpea.6. Enzymatic antioxidant activities in eight wild edible fruits of Odisha.7. Ecology and Phenology of Plant Communities of Gentianaceae in montane grasslands of Karnataka, Southern India.8. Analysis of physico-chemical parameters, genotoxicity and oxidative stress.9. Assessment of forest structure and woody plant regeneration on ridge tops at upper Bhagirathi basin in Garhwal Himalaya.10. Expression of chitinase with antifungal activities in ripening Banana fruit.11. Diversity, utilization and sacred values of Ethno-medicinal plants of Kumaun Himalaya.12. Growth of Papaya grown in pot culture of different soil compositions.13. Potential for exploitation of Dendrocalamus stocksii (Munro.) shoots New report from Peninsular India.TRANSCRIPT
-
www.tropicalplantresearch.com 1 Published online: 31 October 2014
ISSN (E): 2349 1183 ISSN (P): 2349 9265
1(3): 0112, 2014
Research article
Phenology, growth and survival of Vatica lanceaefolia Bl.: A
critically endangered tree species in a moist tropical forest of
Northeast, India
Mrigakhi Borah and Ashalata Devi*
Department of Environmental Science, Tezpur University, Tezpur, Sonitpur, Assam, India
*Corresponding Author: [email protected] [Accepted: 28 September 2014]
Abstract: An attempt has been made to unravel the major phenophases, seedling survival and
growth of Vatica lanceaefolia, a critically endangered tree species in two different micro sites of
Hollongapar Gibbon Wildlife Sanctuary, Assam. The study was carried out for a period of 24
months to investigate various phenophases with respect to seasonal variations of the year and, to
understand the growth and survival of the seedlings in two micro sites (gap and understory) in
relation with the prevailing meteorological parameters of the study area. Leaf flushing was
observed twice in a year in the month of December and May, while flowering and fruiting occurs
during pre-monsoon season (April and May). The seedlings showed better survival in gap (66.6%)
compared to the understory (46.6%) and relative growth rates of the seedlings in terms of height
and collar diameter varied significantly across the months and also between the micro
environmental conditions of the two micro sites (P
-
Borah & Devi (2014) 1(3): 0112 .
www.tropicalplantresearch.com 2
Phenology of vegetative phases is important, as cycles of leaf flush and leaf fall are intimately related to
processes such as growth, plant water status and gas exchanges (Reich 1995). Phenological study is also
essential for seed procurement of plant species. The knowledge on phenology of plants has helped to understand
the influence of phenological events on feeding, movement patterns, and sociality of insects, birds and mammals
(Foster 1982a, Prasad 1983, Coates-Estrada & Estrada 1986). The timing of flowering in plants can serve as an
isolating mechanism in plant speciation (Newstrom et al. 1994). The timing of flowering and fruiting in tropical
trees has been attributed to edaphic, climatic and biotic factors and photoperiod, temperature and soil moisture
have been recognized as the main environmental cues for leafing and flowering (Rathcke & Lacey 1985). In
most tropical forests, variation in rainfall is suggested to be the most significant climatic factor that influences
the phenology of flowering and fruiting (Foster 1974, Hilty 1980, Borchert 1983).
India with a wide range of variation in climate, altitude and physiography exhibits enormous variation in the
life cycle of plants of different regions (Koul & Bhatnagar 2005). Several studies on phenology (Boojh &
Ramakrishnan 1982, Shukla & Ramakrishnan 1982, Ralhan et al. 1985, Bhat 1992, Bajpai et al. 2012, Kaur et
al. 2013) were made in different forest types of India. In recent years phenological studies on some forests of
Assam have been reported by few workers (Nath 2012, Devi & Garkoti 2013, Barman et al. 2014, Devi et al.
2014). However, studies on phenology of tropical moist semi evergreen forest and species specific in particular
of North East India, particularly in Assam have been little worked out.
An understanding of the population status and regeneration behaviour is a pre-requisite for developing
conservation strategies for the threatened species (Upadhaya et al. 2009). Successful regeneration of a species in
nature depends on its ability to withstand disturbance stress that plays a key role in seedling survival and
establishment (Rao et al. 1990). Seedling survivorship relies on many factors, both abiotic and biotic
(Karst et
al. 2011). The process of seedling growth and development of forest trees largely depends on gaps/canopy
openings in the forest created due to natural disturbance or seedling establishment barriers such as topography
(Koide et al. 2011), thus influences the regeneration and species composition of the forest (Khumbongmayum et
al. 2005). A canopy gap is defined as an area opened by the removal of canopy trees, in which most of the living
plants were < 5 m tall and < 50 % of the height of surrounding canopy trees (Runkle 1982). Gap dynamics has
been described by many researchers in tropical (Brokaw 1985, Lawton & Putz 1988, Khumbongmayum et al.
2005, Sapkota et al. 2009, Arihafa & Mack 2012) and sub-tropical forests (Barik et al. 1992, Arunachalam &
Arunachalam 2000, Griffiths et al. 2007), and are being considered as a process capable of influencing the
structure of plant communities, enhanced diversity of forest systems, as it expands environmental heterogeneity,
and chances for the growth of tree species (Yamamoto 2000). Many workers reported better growth and survival
of tree seedlings in tropical (Augspurger 1984) and subtropical (Khan & Tripathi 1991, Rao et al. 1997) forest in
areas with more sunlight and there are evidences of fast growth and better survival of dipterocarp seedlings in
gap compared to understory (Tuomela et al. 1996, Kuusipalo et al. 1997, dOliveira & Ribas 2011). These
studies have suggested gap dynamics as an alternative management technique for the degraded and over- logged
Dipterocarp forests. Studies on species-specific seedling growth and survival in northeast India is sparse with
only a few documentations (Bharali et al. 2012, Saikia & Khan 2012a, Saikia & Khan 2012b).
The present study was carried out to understand the major phenological changes and, seedling growth and
survival of V. lanceaefolia in the study area. The study examines the spatial and temporal changes of
phenophases of the plant species and seasonal variation of seedling growth and survival in different micro-sites.
MATERIAL AND METHODS
Study area
The study was conducted for two years (2010-2012) in Hollongapar Gibbon Wildlife Sanctuary (HGWLS),
which is situated in Mariani, Jorhat District of Assam, India. It covers an area of 20.98 km2 and situated at
2640" to 2645" N and 9420" to 9425" E and is located in the south bank of the Great Brahmaputra river
system at an altitudinal gradient of 100120m above msl. The forest type of the sanctuary is Eastern Alluvial
Secondary Semi Evergreen Forest (1/2/2B/2S2) (Champion & Seth 1968) under moist tropical forest of India,
dominated by plants namely, Dipterocarpus macrocarpus, Vatica lanceaefolia and Mesua ferrea. The sanctuary
is divided into five compartments by the forest department. Continuous pressure by the people of fringe area
mainly in the form of cattle grazing, fishing, illegal felling of trees and fuel wood collection have threatened the
flora and fauna of this sanctuary.
Climate and soil type
-
Borah & Devi (2014) 1(3): 0112 .
www.tropicalplantresearch.com 3
The climate of HGWLS is seasonal with monsoonic pattern of rainfall having four seasons winter
(December to February), pre-monsoon (March to May), monsoon (June to September) and post-monsoon
(October to November). Rainfall data were collected from India Meteorological Department while relative
humidity and temperatures were recorded with the help of a pocket weather station (Kestrel 4000 NV). Winter is
cool and temperature goes down up to 7 C and maximum temperature was recorded 32.4 C in the monsoon
season. Relative humidity ranged from 4095 % during the study period (Fig. 1).
Figure 1. Meteorological parameters of the study area during the study period (July 2010July 2012).
Different micro-environmental variables such as light intensity and edaphic characteristics of the two micro
sites i.e. gap and understory were determined during the study period 20102012. Light intensity was measured
using digital light meter (Extech EasyViewTM
30). A total of 20 soil samples, 10 each from gaps and understory
were collected from the depth of 10 to 15 cm after removing litter accumulation and physicochemical
characteristics of the soil was analysed in the laboratory of Department of Environmental Science, Tezpur
University, Assam. Soil type of the sanctuary is sandy clay loam and the surface soil is largely covered by litter
fall. Light intensity and physicochemical parameters of soil of two micro sites of the study site are given in
Table 1.
Table 1. Physico-chemical parameters of soil and environmental variables recorded in the understory and gap
of HGWLS.
Variables Gap Understory
Light intensity (mol m-2
s-1
) 1235.4-2993.03 52.29-122.60
Soil texture Sandy Clay Loam Sandy Clay Loam
Sand (%) 67.47 68.83
Silt (%) 10.04 9.58
Clay (%) 22.49 21.59
Bulk density (g/cm3) 1.1 1.23
Water holding capacity (%) 49.07 47.22
Soil pH 4.9 5.2
Conductivity (mS/cm) 0.2744 0.296
Available N (%) 0.0109 0.031
Available P (ppm) 6.06 6.01
Available K(ppm) 45.88 46.12
Organic Carbon (%) 1.548 2.12
Organic matter (%) 2.6438 3.82
Study species
Vatica lanceaefolia is a middle canopy evergreen tree species under the family Dipterocarpaceae (Fig. 2A).
The species is distributed randomly in all the five compartments of the sanctuary. The density of the species
inside the sanctuary is 227 individuals per hectare (Sarkar & Devi 2014). V. lanceaefolia is largely collected by
-
Borah & Devi (2014) 1(3): 0112 .
www.tropicalplantresearch.com 4
villager inhabitant in the fringe of the wildlife sanctuary due to its good quality firewood. Large individuals
(girth > 40 cm) of the species are also illegally cut down by the people of surrounding villages for commercial
purpose. During the study period, cut stumps of the species were found to be highest in compartment no. 1 and 5
having 4 and 3 individuals ha-1, respectively.
Figure 2. Vatica lanceaefolia Bl.: A, Adult Tree; B, Seedling; C, Flowers; D, Germinated seeds on the forest floor.
Phenological investigations
Preliminary investigations on major phenological events of V. lanceaefolia were carried out for a period of
two consecutive years (April 2010-March 2012) in Hollongapar Gibbon wildlife sanctuary. A total of twenty
five adult plants (having gbh > 40 cm) with uniform canopy coverage were tagged using Aluminium sheets and
plastic thread in five different compartments of the study site having five individuals in each compartment for
phenological investigation. Monthly observations for phenological changes were made for six major
phenological phases viz., leaf abscission or senescence of leaves, leaf flushing, flowering, fruiting, and dropping
of fruit and vegetative growth. The phenological characteristics are reported as per Newstrom et al. (1993 &
1994) and phenophases were represented with the help of a phenogram.
Survival and growth of seedlings
Two micro sites namely understory and gap were selected for the study of seedling survival and growth of V.
lanceaefolia in HGWLS. The area of gap was measured using the equation for the area of an ellipse, after
measuring the longest axis and its perpendicular shorter axis by laying down long meter tapes (Sapkota et al.
2009). A gap of 942.48 m2 in size inside the forest area located at 264040.2N and 942053.4E were selected
for the purpose of the study. Thirty seedlings of uniform size and shape within height range of 9 to10.5 cm
without any physical damage or herbivory attack were selected in each of the understory and gap (Fig. 2B). To
-
Borah & Devi (2014) 1(3): 0112 .
www.tropicalplantresearch.com 5
analyse the temporal variation of growth of seedlings, plant height (cm) and collar diameter (cm) of each tagged
seedling were measured and recorded at monthly intervals for a period of two years (July 2010-June 2012). The
Relative Growth Rate (RGR) in terms of height (RGRH) and collar diameter (RGRD) was calculated as per the
formula (Hunt 1982).
RGR (tn-1-tn) = lnS(tn)-lnS(tn-1)/ tn-tn-1
Where, S is the plant size, i.e. height (cm) or collar diameter (cm) and t is the time (months).
Seasonal variation for RGRH and RGRD in gaps and understory seedlings of the study site was analysed by
one-way ANOVA and significance in variation of the RGRH and RGRD between the seedlings in gap and
understory was tested using t-test. The correlation between few meteorological parameters viz. relative
humidity, rainfall and average temperature with the relative growth rates of seedlings in both understory and
gaps were analysed. All of these analyses were performed in SPSS software version 16.0.
RESULTS
Phenological observations
Vatica lanceaefolia did not show any significant difference among the phenological events from year to year
during the two years of consecutive study. It was also observed that the meteorological parameters recorded
were more or less same during the two years observation (Fig. 1). The two years study depicts that, leaf
abscission accompanied by large scale leaf flushing of V. lanceaefolia takes place in the month of December.
Flowering takes place once in a year in the month of April, fruit initiation takes place in May with fruit
maturation in late June and dropping of fruit takes place in the month of July. From August to November the
plant species did not show any major event of phenology and it was considered as vegetative growth (Table 2).
In late July, germination of V. lanceaefolia takes place in the forest floor.
Table 2. Monthly phenophases of Vatica lanceaefolia recorded during the study period.
Study years Apr May Jun Jul Aug Sept Oct Nov Dec Jan Feb Mar
2010-2011
20112012
Abbreviations: 1=Leaf abscission, 2=Leaf flushing, 3=Flowering, 4=Fruiting,
5=Dropping of fruit and 6=Vegetative growth.
Survival and growth of seedlings
Seedling survival in two micro sites
J ul Nov Mar J ul Nov Mar J ul
0
50
60
70
80
90
1 00
Seed
ling
surv
ival
(%
)
Months
Gap
Understory
Figure 3. Survival of seedlings (%) of Vatica lanceaefolia in understory and gap during the
study period.
At the end of the study period, the seedling survival percentage of V. lanceaefolia in the two micro sites viz.
understory and gaps was recorded 46.6 % (N=14) and 66.6 % (N=20), respectively. The seedling survival was
comparatively high in gap compared to the understory (Fig. 3). In the first year observation, the mortality rate of
-
Borah & Devi (2014) 1(3): 0112 .
www.tropicalplantresearch.com 6
seedlings in gap was 23.33 % while in the following second year observation mortality rate was reduced with
13.04 %. Similarly, seedlings of understory also showed higher mortality rate of 30 % in the first year of
observation compared to 26.32 % in the second year of observation. Seedling mortality was high in the month of
January and February, which experience the cool and dry winter season in both the study years.
Variation in relative growth rates of seedlings between two micro sites
Relative growth rates in terms of height (RGRH) and collar diameter (RGRD) of the seedlings recorded in
both the micro sites during the study period shows higher increment during the month of May and August which
corresponds to pre-monsoon and monsoon season and less during February (winter season) and November
(post-monsoon season). However, RGRH and RGRD of seedlings exhibit different increment between the gaps
and understory with response to seasonal changes. RGRH of understory seedlings shows slightly higher growth
rate during winter and post-monsoon compared to the seedlings in gap (Fig. 4).
Figure 4. Relative Growth Rates of Vatica lanceaefolia seedlings recorded in understory (U) and gap (G): A, Height
(RGRH); B, Collar Diameter (RGRD).
RGRH (t=4.362, df=11, P=0.001) and RGRD (t=5.575, df=11, P=0.000) of seedlings varied between gap
and understory and the difference was highly significant. RGRH and RGRD of seedlings of V. lanceaefolia in
both the micro sites also varied significantly (P=0.000) across the months {RGRH(U), t=5.41, df=23;
RGRH(G), t=4.794, df=23; RGRD(U), t=4.450, df=23; RGRD(G), t=4.552, df=23}.
It was observed that relative growth rate in terms of height (RGRH) in both understory (U) and gap (G)
exhibited positive correlation with rainfall, relative humidity and average temperature of the study area during
the study period (July 2010Jun 2012). Relative growth rates in terms of collar diameter (RGRD) in understory
(U) and gap (G) also showed little correlations with these meteorological parameters (Table 3).
Table 3. Correlations of RGRH and RGRD of seedlings of understory and gaps with meteorological parameters.
Data from July 2010June 2011 Data from July 2011June 2012
RF RH AVT RF RH AVT
RGRH(U) R=0.637* R=0.602* R=0.687** R=0.786** R=0.544* R=0.609*
RGRH(G) R=0.702** R=0.665** R=0.781** R=0.686** R=0.560* R=0.675**
RGRD(U) R=0.548* R=0.548* R=0.482ns
R=0.452ns
R=0.543* R=0.416ns
RGRD(G) R=0.521* R=0.349ns
R=0.197ns
R=0.673** R=0.395ns
R=0.521*
RF=Rainfall, RH=Relative humidity and AVT =Average temperature
*significant at the 0.05 level
**significant at the 0.01 level ns
not significant
-
Borah & Devi (2014) 1(3): 0112 .
www.tropicalplantresearch.com 7
Absolute height and collar diameter of Vatica lanceaefolia seedlings in gap and understory
At the end of the 12 months observation, the absolute height of the tagged seedlings of V. lanceaefolia
reached 20.70.303 cm and 23.90.259 cm in understory and gap, respectively whereas, collar diameter of the
seedlings reached 1.30.055 cm and 1.60.089 cm, respectively for understory and gap. But the difference in
absolute height of the seedlings in understory and gap was not significant (P>0.05). At the end of the two years
study, the absolute height of the tagged seedlings reached 32.22.25 cm and 35.70.72 cm in understory and
gap, respectively. Correspondingly, collar diameter of the seedlings reached 30.29 cm and 3.60.28 cm,
respectively for understory and gap. Variations in absolute height (t=58.428, df=14, P=0.000) and collar
diameter (t=39.884, df=14, P=0.000) of seedlings of V. lanceaefolia between the two micro sites was highly
significant at the end of two years of observation.
DISCUSSIONS
Phenological observations
From the present study it was revealed that, V. lanceaefolia is an annual flowering plant with brief flowering
(< 1 month) duration (Newstrom et al. 1993 & 1994). Bud initiation in V. lanceaefolia takes place after the first
shower of monsoon or in mid-April and flower fully opens in the month of May. White flowers of the plant
species (Fig. 2C) bear a very mild, pleasant fragrance. Flowering takes place almost at the same time in all the
inflorescences of the plant. Occurrence of peak flowering and fruiting records in the months of April to May
corresponds with the increased temperature during the pre-monsoon season or the summer. Increasing day
length, soil moisture and temperature may have induced flowering during warm pre-monsoon period (Foster
1974, Hilty 1980, Rathcke & Lacey 1985). Regular flowering in some tropical deciduous trees after the spring
equinox during MarchJune has been reported by many workers (Felger et al. 2001, Singh & Kushwaha 2006).
After 25 days of flowering fruit initiation takes place as the monsoon rain starts and earlier studies also
suggested that the seasonal availability of water is the primary determinant of fruiting (Foster 1974, Borchert
1983, Bach 2002). Fruit maturation takes place in June during the monsoon period. The need of high moisture
level for the proper development of fleshy fruits has been reported by Zahner (1968), and it was also showed
experimentally that the shortage of soil moisture reduces the rate of enlargement and final size of fruits. Seeds of
V. lanceaefolia germinates without any dormancy period within 6-10 days of dropping, in late July which was
favoured by the sufficient availability of soil moisture content due to heavy precipitation and prevailing warm
temperature (Fig.2D). This relationship of germination with availability of soil moisture has also been supported
by several earlier studies (Foster 1982b, Shukla & Ramakrishnan 1982, White 1994, Bach 1998). In relation to
temperature, genera Vatica are known to germinate at temperatures above 14C (Yap 1981). In general seedlings
of dipterocarps germinate quickly in warm and moist climate (Tompsett 1986).
Flushing and leaf production completes towards the end of the dry season, before the onset of rains. Leaf fall
occurs when temperature declines and day length becomes short during winter which is also supported by earlier
studies (Shukla & Ramakrishnan 1984, Bhat 2001). There are several reports of maximum leaf-fall during the
driest period of the year in different tropical forest types (Richards 1952, Frankie et al. 1974, Opler et al. 1980,
Liberman & Liberman 1984). During dry season leaf abscission may be attributed to avoid water stress. It was
found that leaf flushing and leaf fall in V. lanceaefolia requires low temperature (2025C) and low relative
humidity (4050 %). In February the plant bears completely new leaves in its branches. This has also been
shown for other seasonal tropical forests (Boaler 1966, Frankie et al. 1974). After maturation of leaves, heavy
insect infestation is observed during the study period (personal observation). Studies have shown that seasonal
peaks and depressions for leaf flush and leaf fall are quite common in tropical rain forests with pronounced dry
period (Kramer & Kozlowski 1960, Fogden 1972). In tropics emergence of leaves peaked either in dry season
(Frankie et al. 1974, Whitmore 1984) or in the wet season (Fogden 1972, Proctor et al. 1983). Leaf flushing
during dry season probably permit renovation of the canopy before the onset of monsoon, so that the plant
becomes able to take full advantage of the rainy season to produce and store nutrients for their growth and
development. A small scale of leaf flushing observed in the month of May during the second year of observation
indicates minor difference in phenological events during the two year of study periods. However, such slight
variation could not interpret any remarkable changes in phenological events of the species and it may be stated
that the two year phenological observation of V. lanceaefolia reveals more or less similar pattern of phenophase
which corresponds with the recorded meteorological parameters.
Survival and growth of seedlings
-
Borah & Devi (2014) 1(3): 0112 .
www.tropicalplantresearch.com 8
During the two years of seedling survival and growth study, seedling mortality was recorded highest both in
understory and gap during the cold dry winter season (December to February) which resulted in sudden decline
in the survival percentage of the seedlings in the month of March in both the study years (Fig. 3). Large number
of mortality of seedlings during the winter season may be due to the detrimental effect of soil moisture stress on
the seedlings which has been stated by many workers (Khan et al. 1986, Kikim 1999, Khumbongmayum et al.
2005). From June, with the onset of monsoon and increase in soil moisture content, survival rate of the seedlings
was stabilized. Increase in survival rate of seedlings during the wet season is reported by various researchers
(Tompsett 1986, Lieberman & Li 1992, Bharali et al. 2012). Lower mortality rate recorded in the second year
observation than the first year observation may be attributed due the establishment of the seedling towards the
preliminary stage of sapling.
From the present study it was found that, RGRH, RGRD and absolute height of seedlings of V. lanceaefolia
is affected by different micro-environmental conditions and the seedling survival was favourable in gap (66.6
%) compared to the understory (46.6 %). Better growth and survival is recorded in a large number of plant
species in gaps compared to understory by many workers (Brokaw 1985, 1987, Welden et al. 1991, Nagamastu
et al. 2002). Higher light intensity and the prevailing micro-environmental conditions in gap may have
influence in the better growth rates of seedlings of V. lanceaefolia compared to the understory (Table 1). The
effect of light (Burton & Mueller-Dombois 1984, Connel et al. 1984) and temperature (Sorenson & Ferrel
1973) in regulating the growth of tree seedlings in tropical forests has been reported earlier by many workers.
Seasonal variability in growth response to light environment is an important parameter to determine the growth
of subtropical tree species (Khumbongmayum et al. 2005). Growth in terms of height and collar diameter of the
seedlings increased in both understory and gap during pre-monsoon and monsoon period probably because of
the rainfall, as it shows significant positive correlation with the rainfall of the study area during the study
period, however, growth rate decreases during cold dry seasons from November to February (post-monsoon and
winter) (Fig. 4). These may be attributed to the high moisture content in soil along with the high surface
temperature. The peak seedling growth during rainy season may be because of the increased availability of
nutrients in soil due to rapid decomposition of litter on the forest floor and because of the higher moisture
content of the soil (Mueller-Dombois et al. 1980, Khumbongmayum et al. 2005). It was observed that, relative
growth rates in terms of height and collar diameter of the seedlings in understory and gap also increases with
the increase in relative humidity during the monsoon period. Growth performance was highest in the months of
April to September with higher relative humidity and least in the months of November to February with lower
relative humidity. Growth reduction in plants due to low relative humidity of the air is reported earlier (Grantz
1990).
Prevailing average temperature of the study area also exhibited positive correlation with the seedling growth
performance. This reveals that, seedling growth of V. lanceaefolia is largely influenced by rainfall, relative
humidity and average temperature of the study area. It can be concluded that, seedling growth of V. lanceaefolia
shows better in gaps and growth rate increases with increase in soil moisture regime, ambient temperature and
rainfall during the summer monsoon season.
CONCLUSIONS
The present study reports the timing of occurrence of different phenological phases of Vatica lanceaefolia,
an annual flowering plant. Senescence of old leaves occurs with the onset of large scale leaf flushing as a
simultaneous process in the cold dry winter months. Flowering and fruiting occurs once in a year in pre-
monsoon season. Dropping of mature fruit takes place in late July and correspondingly germination of seeds
starts on the forest floor. The study also reveals that, seedling growth of V. lanceaefolia is significantly affected
by different micro-environmental conditions in terms of their survival and growth parameters. Significantly
higher growth performance was observed in the seedlings growing in gap area compared to the understory
during the study period in HGWLS. Thus, plantation of V. lanceaefolia seedlings in the gaps or in open areas
will be a fruitful measure to multiply the number of this critically endangered plant species in their habitat.
Germination showed dependency on water availability in the soil as it starts in the rainy season without any
dormancy period. Monthly relative growth rate (RGR) in terms of height and collar diameter indicates
dependency of the species on wet season as growth rates were found higher during the rainy hot months
compared to the cool dry months. The long rainy season from April to September (pre-monsoon and monsoon)
during the study period had a positive impact on the growth and development of seedlings in both the micro
sites, which was associated with the major changes in the phenological events of the plant.
-
Borah & Devi (2014) 1(3): 0112 .
www.tropicalplantresearch.com 9
Presently the sanctuary harbours a good density of V. lanceaefolia, but continuous anthropogenic pressure
exerted in terms of illegal cutting and felling for the purpose of firewood has emerged as a serious threat to the
survival of this species. So, possible measures should be undertaken to control the illegal logging of this species
by the fringe village people and proper strategies should be adopted to conserve the plant and multiply its
number in the study area in particular and other similar habitats of the species in northeast India in general. This
investigation on phenological characteristics and survival and growth of seedlings on this species is a pioneer
study and data of the present study may be helpful not only in the formulation of conservation strategies but also
in implementing further research aspects of this species viz. reproductive phenology, chemical analysis, genetic
improvement, etc.
ACKNOWLEDGEMENTS
The authors are thankful to the Principal Chief Conservator of Forests (Wildlife), Basistha, Guwahati,
Assam, for his kind permission to carry out the research work in HGWLS. Sincere thanks to forest officials of
Meleng Beat Office, HGWLS especially, Mr. Daben Borah, for his kind assistance during the entire field work.
We also thank Dr. Manoranjan Nath, Dr. Rajeev Basumatary and Dr. Gitamani Dutta for their valuable
suggestions and help.
REFERENCES
Arihafa A & Mack AL (2012) Treefall gap dynamics in a tropical rainforest in Papua New Guinea. Pacific
Science 67(1): 126.
Arunachalam A & Arunachalam K (2000) Inuence of gap size and soil properties on microbial biomass in a
subtropical humid forest of north-east India. Plant and Soil 223: 185193.
Augspurger CK (1984) Pathogen mortality of tropical seedlings: Experimental studies of the effect of dispersal
distance, seedling density and light conditions. Oecologia 61: 211217.
Bach CS (2002) Phenological patterns in monsoon rainforests in the Northern Territory, Australia. Austral
Ecology 27(5): 477489.
Bach CS (1998) Resource patchiness in space and time: Phenology and reproductive traits of Monsoon
Rainforests at Gunn Point, Northern Territory, Australia. Ph.D. Thesis, Northern Territory University,
Darwin, Australia.
Bajpai O, Kumar A, Mishra AK, Sahu N, Behera SK & Chaudhury LB (2012) Phenological study of two
dominant tree species in tropical moist deciduous forest from the northern India. International Journal of
Botany 8(2): 6672.
Barik SK, Pandey HN, Tripathi RS & Rao P (1992) Microenvironmental variability and species-diversity in tree
fall gaps in a subtropical broadleaved forest. Vegetatio 103: 3140.
Barman D, Nath N & Deka K (2014) Phenology of some medicinal plant species of Goalpara District, Assam
(India). Scholars Academic Journal of Biosciences 2(2): 8184.
Bharali S, Paul A, Khan ML & Singha LB (2012) Survival and Growth of Seedlings of Two Rhododendron
Tree Species along an Altitudinal Gradient in a Temperate Broad Leaved Forest of Arunachal Pradesh,
India. International Journal of Plant Research 2(1): 3946.
Bhat DM & Murali KS (2001) Phenology of understory species of tropical moist forest of Western Ghats region
of Uttara Kannada district in South India. Current Science 81: 799805.
Boaler SB (1966) Ecology of a miombo site, Lupa North Forest Reserve, Tanzania II. Plant communities and
seasonal variation in the vegetation. Journal of Ecology 54: 465479.
Boojh R & Ramakrishnan S (1982) Growth strategy of trees related to successional status II. Leaf dynamics.
Journal of Forest Ecology and Managemment 4: 375386.
Borchert R (1983) Phenology and control of flowering in tropical trees. Biotropica 15(2): 8189.
Brokaw NVL (1985) Gap phase regeneration in a tropical forest. Ecology 66: 682687.
Brokaw NVL (1987) Gap phase regeneration of three pioneer tree species in a tropical forest. Journal of
Ecology 75: 919.
Burton PJ & Mueller-Dombois D (1984) Response of Metrosidros polymorpha seedlings to experimental
canopy. Ecology 5: 779791.
Champion HG & Seth SK (1968) A revised survey of the forest types of India. The Manager of Publications,
Delhi.
-
Borah & Devi (2014) 1(3): 0112 .
www.tropicalplantresearch.com 10
Coates-Estrada R & Estrada A (1986) Fruiting and frugivores at a strangler fig in the tropical rain forest of Los
Tuxtlas, Mexico. Journal of Tropical Ecology 2: 349357.
Connell J, Tracey JG & Webb JL (1984) Compensatory recruitment, growth and mortality as factors
maintaining rainforest tree diversity. Ecological Monograph 54: 141-164.
dOliveira MVN & Ribas LA (2011) Forest regeneration in articial gaps twelve years after canopy opening in
Acre State Western Amazon. Forest Ecology and Management 261: 1722-1731.
Devi AF & Garkoti SC (2013) Variation in evergreen and deciduous species leaf phenology in Assam, India.
Trees 27: 985997.
Devi AF, Garkoti SC & Borah N (2014) Periodicity of leaf growth and leaf dry mass changes in the evergreen
and deciduous species of Southern Assam, India. Ecological Research 29: 153165.
Felger RS, Johnson MB, Wilson MF (2001) The trees of Sonora. Oxford University Press, Oxford, pp. 391.
Fogden L (1972) The seasonality and population dynamics of equatorial forest birds in Sarawak. Ibis 114:
307342.
Foster RB (1974) Seasonality of fruit production and seed fall in a tropical forest ecosystem in Panama. Ph.D.
Dissertation, Duke University, Durham, North Carolina.
Foster RB (1982b) The seasonal rhythm of fruitfall on Barro Colorado Island. In: Leigh EGJr, Rand AS &
Windsor DM (eds) The Ecology of a Tropical Forest: Seasonal Rhythms and Long-Term
Changes. Smithsonian Institution Press, Washington DC, pp. 151172.
Foster R (1982a) Famine on Barro Colorado Island. In: Leigh GJr, Rand AS & Windsor D (eds) The
ecology of a tropical forest, seasonal rhythms and long-term changes. Smithsonian Institution Press,
Washington, pp. 201212.
Frankie GW, Baker G & Opler (1974) Comparative phenological studies of trees in tropical wet and dry
forests in the low lands of Costa Rica. Journal of Ecology 62: 881919.
Grantz DA (1990) Plant response to atmospheric humidity. Plant, Cell & Environment 13(7): 667679.
Griffiths ME, Lawes MJ & Tsvuura Z (2007) Understory gaps influence regeneration dynamics in subtropical
coastal dune forest. Plant Ecology 189: 227236.
Harper JL (1977) Population biology of plants. Academic Press, London, pp. 892.
Hilty SL (1980) Flowering and fruiting periodicity in a premontane forest in Pacific Colombia. Biotropica
12(4): 292306.
Hunt R (1982) Plant growth curves: The Functional Approach to Plant Growth Analysis. Edward Arnold,
London, 248 p.
IUCN (2014) IUCN Red List of Threatened Species, Version 2014.2. Available from:
http://www.iucnredlist.org. (accessed: 22 Sept. 2014).
Karst J, Hoeksema JD, Jones MD & Turkington R (2011) Parsing the roles of abiotic factors in Douglas-fir
seedling growth. Pedobiologia 54: 273280.
Kaur G, Singh BP & Nagpal AK (2013) Phenology of Some Phanerogams (Trees and Shrubs) of Northwestern
Punjab, India. Journal of Botany 2013: 1-10.
Khan ML & Tripathi RS (1991) Seedling survival growth of early and late successional tree species as affected
by insect herbivory and pathogen attack in sub-tropical humid forest stands of north east India. Acta
Oecologia 12: 569579.
Khan ML, Rai JPN & Tripathi RS (1986) Regeneration and survival of tree seedlings and sprouts in tropical
deciduous and sub tropical forests of Meghalaya, India. Forest Ecology and Management 14: 293304.
Khumbongmayum AD, Khan ML & Tripathi RS (2005) Survival and growth of seedlings of a few tree species
in the four sacred groves of Manipur, Northeast India. Current Science 88(11): 17811788.
Kikim AD (1999) Vegetation dynamics and regeneration of some trees in sub tropical forests of Manipur. PhD
thesis, Manipur University, Manipur.
Koide RT & Fernandez C (2011) General principles in the community ecology of ectomycorrhizal fungi. Annals
of Forest Science 68: 4555.
Koul M & Bhatnagar AK (2005) Phenology and climate change. Current Science 89: 243244.
Kramer J & Kozlowski (1960) Physiology of trees. McGraw Hill, New York, pp. 642.
Kuusipalo J, Hadengganan S, Adjers G & Sagala APS (1997) Effect of gap liberation on the performance and
growth of dipterocarp trees in a logged-over rainforest. Forest Ecology and Management 92: 209219.
Lawton RO & Putz FE (1988) Natural disturbance and gap-phase regeneration in a wind-exposed tropical cloud
forest. Ecology 69(3): 764777.
-
Borah & Devi (2014) 1(3): 0112 .
www.tropicalplantresearch.com 11
Lieberman D & Li M (1992) Seedling recruitment patterns in a tropical dry forest in Ghana. Journal of
Vegetation Science 3: 375382.
Lieberman D & Lieberman M (1984) The causes and consequences of synchronous flushing in a dry tropical
forest. Biotropica, 16: 193201.
Mueller-Dombois D, Jacobi JD, Cooray RG & Balakrishnan N (1980) Ohia rainforest study: Ecological
investigations of the Ohia dieback problem in Hawaii. Miscellaneous Publication, Hawaii Institute of
Tropical Agriculture and Human Resources, Honolulu, HI, 183 p.
Nagamastu D, Seiwa K & Sakai A (2002) Seedling establishment of deciduous trees in various topographic
positions. Journal of Vegetation Science 13: 35-44.
Nath N (2012) Phenological Study of Some Tree Species of Sri Surya Pahar of Goalpara District, Assam, Indian
Journal of Fundamental and Applied Life Sciences 2 (1): 102104.
Newstrom LE, Frankie GW & Baker HG (1994) A New Classification for Plant Phenology Based on Flowering
Patterns in Lowland Tropical Rain Forest Trees at La Selva, Costa Rica. Biotropica 26(2): 141159.
Newstrom LE, Frankie GW, Baker HG & Colwell RK (1993) Diversity of flowering patterns at La Selva. In:
McDade LA, Bawa KS, Hartshorn GS & Hespenheide HA (eds) La Selva: ecology and natural history of a
lowland tropical rainforest. University of Chicago press, Chicago, Illnois.
Opler PA, Frankie GW & Baker HG (1980) Comparative phenological studies of treelet and shrub species in
tropical wet and dry forests in the lowlands of Costa Rica. Journal of Ecology 68: 16788.
Prasad NLNS (1983) Seasonal changes in the herd structure of Blackbuck. Journal of Bombay Natural History
Society 80: 549554.
Proctor J, Anderson JM, Fogden SCL & Vallack W (1983) Ecological studies in four contrasting lowland
rainforests in Gunung Mulu National Park Sarawak. II. Litterfall, litter standing crop and preliminary
observation on herbivory. Journal of Ecology 71: 261283.
Ralhan , Khanna RK, Singh S & Singh JS (1985) Phenological characteristics of the shrub layer of Kumaun
Himalayan forests. Vegetatio 63: 113119.
Rao P, Barik SK, Pandey HN & Tripathi RS (1990) Community composition and tree population structure in a
subtropical broad-leaved forest along a disturbance gradient. Vegetatio 88: 15112.
Rao P, Barik SK, Pandey HN & Tripathi RS (1997) Tree seed germination and seedling establishment in tree
fall gaps and understory in a subtropical forest of north-east India. Australian Journal of Ecology 22: 136
145.
Rathcke & Lacey (1985) Phenological patterns of terrestrial plants. Annual Review of Ecology, Evolution,
and Systematics 16: 179214.
Reich PB (1995) Phenology of Tropical Forests: Patterns, Causes and Consequences. Canadian Journal of
Botany 73: 14174.
Richards PW (1952) The Tropical Rain Forest: An Ecological Study. Cambridge University Press, London.
Runkle JR (1982) Patterns of disturbance in some old-growth mesic forests of eastern North America. Ecology
63: 15331546.
Saikia P & Khan ML (2012a) Seedling survival and growth of Aquilaria malaccensis in different microclimatic
conditions of northeast India. Journal of Forestry Research 23(4): 569574.
Saikia P & Khan ML (2012b) Phenology, Seed Biology and Seedling Survival and Growth of Aquilaria
Malaccensis: a Highly Exploited and Red Listed Tree Species of North East India. The Indian Forester
138(3): 289295.
Sapkota IP, Tigabu M, Oden PC (2009) Species diversity and regeneration of old growth seasonally dry Shorea
robusta forests following gap formation. Journal of Forestry Research 20:714.
Sarkar M & Devi A (2014) Assessment of diversity, population structure and regeneration status of tree species
in Hollongapar Gibbon Wildlife Sanctuary, Assam, Northeast India. Tropical Plant Research 1(2): 2636.
Shiva MP & Jantan I (1998) Non timber forest products from dipterocarps. In: Appanah S & Turnbull JM (eds)
A Review of Dipterocarps: taxonomy, ecology and silviculture. Center for International Forestry Research,
Bogor, Indonesia, Chapter 10, 223 p.
Shukla R & Ramakrishnan S (1982) Phenology of trees in a sub tropical humid forest in north Eastern India.
Vegetatio 49: 103-109.
Shukla R & Ramakrishnan S (1984) Leaf dynamics of tropical trees relation to successional status. New
Phytologist 97: 697706.
-
Borah & Devi (2014) 1(3): 0112 .
www.tropicalplantresearch.com 12
Singh KP & Kushwaha CP (2006) Diversity of Flowering and Fruiting Phenology of Trees in a Tropical
Deciduous Forest in India. Annals of Botany 97(2): 265276.
Sorenson FC & Ferrel WK (1973) Photosynthesis and growth of Douglas-fir seedlings which are grown in
different environments. Canadian Journal of Botany 51: 16891698.
Tompsett PB (1986) The effect of desiccation on the viability of dipterocarp seed. In: Nather J (ed) Seed
problems under stressful conditions. Proceeding of the IUFRO Symposium, Federal Research Institute,
Vienna, pp. 181202.
Tuomela K, Kuusipalo J, Vesa L, Nuryanto K, Sagala APS & Adjers G (1996) Growth of dipterocarp seedlings
in artificial gaps: an experiment in a logged-over rainforest in South Kalimantan, Indonesia. Forest Ecology
and Management 81: 95100.
Upadhaya K, Barik SK, Adhikari D, Baishya R & Lakadong NJ (2009) Regeneration ecology and population
status of a critically endangered and endemic tree species (Ilex khasiana Purk.) in north-eastern India.
Journal Forestry Research 20(3): 223228.
Welden CW, Hewett SW, Hubbell SP & Foster RB (1991) Sapling survival, growth and recruitment:
Relationship to canopy height in a neotropical forest. Ecology 72: 3550.
White LJT (1994) Patterns of fruit-fall phenology in the Lope Reserve, Gabon. Journal of Tropical Ecology
10: 289312.
Whitmore C (1984) Tropical rainforests of the Far East. Clarendon Press, Oxford, 2nd edition.
Yamamoto S (2000) Forest Gap Dynamics and Tree Regeneration. Journal of Forestry Research 5: 223229.
Yap SK (1981) Collection, germination and storage of dipterocarp seeds. Malaysian Forester 44: 281-300.
Zahner R (1968) Water deficits and growth of trees. In: Kozlowskl TT (ed) Water Deficits and Plant Growth.
Academic Press, New York.
Zhang G, Song Q & Yang D (2006) Phenology of Ficus racemosa in Xishuangbanna, Southwest China.
Biotropica 38(3): 334341.
-
www.tropicalplantresearch.com 13 Published online: 31October 2014
ISSN (E): 2349 1183 ISSN (P): 2349 9265
1(3): 13 15, 2014
Research article
Pogonatum perichaetiale subsp. thomsonii (Mitt.) Hyvnen -
An uncommon species from western Himalaya
Vinay Sahu and A.K. Asthana*
Bryology Laboratory, CSIR-National Botanical Research Institute Lucknow- 226 001, India
*Corresponding Author: [email protected] [Accepted: 10 October 2014]
Abstract: The present study deals with the investigation of Pogonatum perichaetiale subsp.
thomsonii from Watan Village, Pithoragarh. The important characteristics of this species are plants
simple, leaves stiff, tufted and forming a bud like structure when dry, margin sharply toothed in
upper part of the leaves, costa ends in a sharp awn like point. Leaf base 1/4 to 1/5 of the total leaf
length, lamellae 5 6 cells high, end cells of lamellae thick walled, smooth rectangular. The present
study recognizes Pogonatum perichaetiale subsp. thomsonii a rare species from Uttarakhand
which is a new addition to west Himalayan bryoflora of India.
Keywords: Polytrichaceae - Awn like point - Lamellae - End cells - India.
[Cite as: Sahu V & Asthana AK (2014) Pogonatum perichaetiale subsp. thomsonii (Mitt.) Hyvnen - An
uncommon species from western Himalaya. Tropical Plant Research 1(3): 1315]
INTRODUCTION
Genus Pogonatum belongs to family polytrichaceae. This genus is easily recognized by its thick, rough
textured leaves and hairy calyptra. In India this genus is represented by 18 species (Gangulee 1969, Hyvnen
1989, Asthana & Sahu 2012, Sahu & Asthana 2013). Gangulee (1969) described 4 species within section
Cephalotrichum (C. Muell.) Broth. from eastern India (P. perichaetiale ( Mont.) A. Jaeger, P. thomsonii (Mitt.)
A. Jaeger, P. tortipes (Mitt.) A. Jaeger and P. muticum Broth.). Hyvnen (1989) synonmized P. thomsonii
(Mitt.) Jaeag. and P. tortipes (Mitt.) A. Jaeger under P. perichaetiale subsp. thomsonii and P. muticum into P.
neesii (Mll. Hal.) Dozy. Only two valid species were reported in the section Cephalotrichum from India at
present. P. perichaetiale subsp. thomsonii can easily be distinguished from P. perichaetiale subsp. perichaetiale
with serrated leaf margin and aristate leaves. The key characters of this taxon are: leaves aristate, margin
serrulate at top, forming a bud like structure when dry and end cells of lamellae thick walled, quadrate to short
rectangular. Chopra & Kumar (1981) described 6 species from western Himalaya and adjacent plains (P.
perichaetiale, P. thomsonii, P. himalayanum Mitt., P. microstomum (R. Br. ex Schwgr.) Brid., P. neesii, P.
urnigerum (Hedw.) P. Beauv.), out of which 4 taxa are valid. The present study has revealed Pogonatum
perichaetiale subsp. thomsonii as a new addition to Uttarakhand, west Himalayan bryoflora.
MATERIAL AND METHODS
Plant specimens were collected from Watan Village, Pithoragarh district of Uttarakhand, western Himalaya,
India. Plants were air dried and transferred to brown packets. For morphological and anatomical study plant
samples were soaked and washed in tap water and were mounted on glass microslide in 30 % glycerine to
investigate under microscope. Sections were cut free hand with a razor blade. Observations were made under
Olympus compound microscope. The measurements were taken with the help of oculometer. The voucher
specimens were deposited in Bryophyte Herbarium, National Botanical Research Institute, Lucknow (LWG).
TAXONOMIC DESCRIPTION
Pogonatum Palisot de Beauvois in Mag. Enc., 5: 329 (1804).
Plants usually dioicous, stiff, robust, erect, simple. Leaves curled to crispate when dry and erectopatent when
moist. Leaves lanceolate from a sheathing bases, margin not bordered, usually serrate at upper portion and
numerous longitudinal lamellae on ventral surface. Leaf costa percurrent to excurrent. Seta long, capsule erect to
inclined, subcylindrical, stomata absent. Peristome teeth 32, sometimes 16, calyptra hairy, cucullate.
-
Sahu & Asthana (2014) 1(3): 13 15 .
www.tropicalplantresearch.com 14
Figure 1. Pogonatum perichaetiale subsp. thomsonii: A, Plant in dry condition; B, Plant in wet condition; C, Leaves; D,
Apical margin of Leaf; E & F, Cross sections of leaves showing Lamellae; G, Apical cells of leaf; H, median cells of leaf;
I, basal cells of leaf.
P. perichaetiale subsp. thomsonii comes under the section Cephalotrichum. The important characteristics of
this section are that plants are small, stiff, leaves tufted at top. Leaf margin dentate at apex or entire, costa
excurrent in a sharp point or ending at the tip into a long awn like point. Lamellae 4 5cells high (sometimes up
to7), end cells bigger quadrate to rectangular, thick walled, smooth and 16 Peristome teeth each having a
bifurcated axial pillar.
Pogonatum perichaetiale subsp. thomsonii (Mitt.) Hyvnen, in a synopsis of genus Pogonatum (Polytrichaceae,
Musci). Acta Bot. Fennica 138: 1 87 (1989). (Fig. 1).
Polytrichum thomsonii Mitt., J. Linn. Soc. Bot. Suppl. 1:155 (1859).
Pogonatum thomsonii (Mitt.) A. Jaeger. Ber. Thtigk. St. Gallischen Naturwiss. Ges. 1873 74: 257 (1875);
Pogonatum tortipes (Mitt.) A. Jaeger. Ber. Thtigk. St. Gallischen Naturwiss. Ges. 1873 74: 257 (1875);
Pogonatum thomsonii var. tibetanum Chen, Sci. Exped. Qomolongma Reg. 235.14 (1962).
-
Sahu & Asthana (2014) 1(3): 13 15 .
www.tropicalplantresearch.com 15
Plants dark brown, erect, simple, 12 15 mm long. Leaves stiff, tufted and forming a bud like structure when
dry, Lower leaves small. Leaves erectopatent, lanceolate from a wider transparent sheathing base, 4 5 mm long
and 0.96 1.12 mm wide, margin sharply toothed in upper part of the leaves. Leaf costa ends in a sharp awn like
point. Leaf base 1/4 to 1/5 of the total leaf length. In cross section of leaf, lamellae covering almost the entire
ventral leaf surface, lamellae 5 6 cells high, end cells of lamellae thick walled, smooth reddish brown,
rectangular with top cell flat or rounded. Apical cells of leaf 12 16 m long and 8 12 m wide, short quadrate.
Basal cells of leaf 20 40 m long and 12 20 m wide, quadrate to rectangular. Leaf costa 140 160 m wide at
base. Sporophyte not seen.
Specimens examined: INDIA, Western Himalaya, Uttarakhand, Pithoragarh, Near Watan Village, 27.09.1990,
V. Nath 205087A (LWG).
Habitat: ca. 3500 m, on soil.
Distribution: India (Simla, Sikkim), Bhutan, South eastern Tibet, Nepal, China.
Hyvnen (1989) synonymized Pogonatum thomsonii and P. tortipes under P. perichaetiale subsp.
thomsonii. In the case of P. tortipes end cells of lamellae are smooth, thick walled, 4 5 cells high, elongated
rectangular with top cells flat and leaf basal part 1/3 of total leaf length, basal cells rectangular up to 145m
long and 24 m wide while in P. thomsonii end cells of lamellae cup shaped with depressed top, lamellae 5 7
cells high, basal leaf cells up to 60m long and 17 m wide (Gangulee 1969). Characteristic end cells of
lamellae and basal leaf portion might be the reason for making P. perichaetiale subsp. thomsonii as separate
subspecies. In our specimens end cells of lamellae are 5 6 cells high, thick walled, smooth, elongated
rectangular, with top cells flat or rounded and basal portion of leaf 1/4 to 1/5 of the total leaf length. P. tortipes
was collected by Hooker in Japanese Expeditions in 1960 63 from Sikkim and it is known in India from that
collection only. Chopra & Kumar (1981) examined the specimen no. 6202 (BM) of P. thomsonii but in that
specimen date of collection and altitude was not mentioned. Pogonatum perichaetiale subsp. thomsonii is very
rare and it has been collected from Pithoragarh, western Himalaya after 30 years. It is still untraced despite
several collections in the area in past few decades. After Hyvnen treatment of this taxon, the plants have been
identified and described from Pithoragarh region of western Himalaya for the first time.
ACKNOWLEDGEMENTS
Authors are grateful to the Director, National Botanical Research Institute (CSIR), Lucknow for
encouragement and providing the facilities and work has been carried out under In house project OLP-0083.
REFERENCES
Asthana AK & Sahu V (2012) Two mosses new to western Himalayan Bryoflora. Phytotaxonomy 12: 6367.
Chopra RS & Kumar SS (1981) Mosses of the western Himalayas and adjacent plains. Published by The
Chronica Botanica Co., New Delhi, India, 142 p.
Gangulee HC (1969) Mosses of Eastern India and adjacent regions Vol I. Published by Author, printed at Sree
Saraswati Press, Calcutta, India, pp. 94180.
Hyvnen J (1989) A synopsis of genus Pogonatum (Polytrichaceae, Musci). Acta Botanica Fennica 138: 187.
Sahu V & Asthana AK (2013) Genus Pogonatum P. Beauv. in Singalila National Park (Darjeeling), eastern
Himalaya, India. Geophytology 43(2): 11724.
-
www.tropicalplantresearch.com 16 Published online: 31October 2014
ISSN (E): 2349 1183 ISSN (P): 2349 9265
1(3): 1621, 2014
Research article
Species composition and structure of Sal (Shorea robusta
Gaertn. f.) forests along disturbance gradients of Western
Assam, Northeast India
Debajit Rabha
Department of Ecology & Environmental Science, Assam University, Silchar, Assam, India
Corresponding Author: [email protected] [Accepted: 12 October 2014]
Abstract: The present paper deals with the structure and species composition of undisturbed and
disturbed secondary Sal forests of Goalpara district, Western Assam, Northeast India. Species
richness was recorded very low with only 3 species in undisturbed Sal forests compare to the 18
species in disturbed Sal forests. The density and basal area were recorded high in undisturbed
forests than the disturbed one. Shorea robusta is the single dominant species and constitute the
bulk of the stocks in both forests types. Girth class distribution of density revealed the dominance
of middle girth classes in undisturbed forests whereas in disturbed forests 45 % of the total density
recorded in lowermost girth class. Anthropogenic disturbances influence the forests structure,
functions as well as services in both forests types in the present study.
Keywords: Species diversity - Density - Disturbance index - Sal forests.
[Cite as: Rabha D (2014) Species composition and structure of Sal (Shorea robusta Gaertn. f.) forests along
distribution gradients of Western Assam, Northeast India. Tropical Plant Research 1(3): 1621]
INTRODUCTION
Sal (Shorea robusta Gaertn. f.) is one of the dominant tree species in the tropical moist as well as dry
deciduous forests in India (Champion & Seth 1968) and frequently forms a mono-specific canopy (Rautiainen &
Suoheimo 1997). Sal is well known for its high timber value and government always attempted to manage Sal
forests for commercial timber production in order to increase revenue (Gautam & Devoe 2006). Sal tree grows
gregariously and tends to form dense vegetation in its natural habitat. Natural Sal forests have high resilience
capacity and survive through regeneration (Soni 1961, Qureshi et al. 1968). In India, Sal forests are found to
occur gregariously in the northern and central regions and cover approximately 13.30% of the total forest area of
the country (Upreti & Nayaka 2005). There is almost a continuous belt of Sal stretching along the sub-
Himalayan tract from Punjab to Assam (Pandey & Shukla 2003) in the northern Indian region.
In Assam, Sal is a semi-deciduous species and found in the form of high forest and coppice forest confined
specially to the Western part of Assam (Sarma & Das 2012). Champion & Seth (1968) categorized Assams Sal
forests as Tropical Moist Deciduous Forest further divided into Khasi hill Sal forest (3C/C1 1a (ii)) and
Kamrup Sal forest (3C/C2 2d (iv)). Kamrup Sal forests are more prominent and confined in Western part of
the state.
Disturbances not only influence diversity but also regeneration and dominance of tree species (Lawes et al.
2007). Recurrent anthropogenic disturbances treated as a major threat of natural Sal forests which can change its
structure as well as function (Lalfakawma et al. 2009). Due to the ongoing over-exploitation, deforestation,
encroachment and alteration in land use and land cover the mother Sal forests gradually replace by secondary
regenerated Sal forest of the low lying areas of Assam (Deka et al. 2012). Again regeneration was very poor
where soil moisture is inadequate and which experienced higher degree of disturbances such as fire and different
human activities (Padey & Shukla 2001, Chauhan et al. 2008). Chitale & Behera (2012) stated that moisture is
one of the key factors that influence the distribution to shift the Sal forests towards northern and eastern India
due to changing climate. Ahmed & Medhi (2005) estimated that there was shrinkage of 1050.46 hectares reserve
forests and proposed reserve forest areas of Goalpara District during the period 19812002 due to encroachment
for human habitation, pasture and agricultural uses. These are causing loss of Sal forest trees at a very fast rate,
thereby encouraging the spread of mix forest communities (Sarma & Das 2012). Timely, accurate assessment
-
Rabha (2014) 1(3): 1621 .
www.tropicalplantresearch.com 17
and understanding of the dynamics of plant resources is important for their sustainable management, utilization
and biodiversity conservation (Sarkar & Devi 2014). Comparatively a good number of quantitative studies of
community attributes are available for tropical Sal forest of northeast India (Uma Shankar 2001, Ahmed &
Medhi 2005, Lalfakawma et al. 2009, Deka et al. 2012, Sarma & Das 2012, Dutta & Devi 2013) but in Western
part of Assam which constitute the major partion of Kamrup Sal forest (Champion & Seth 1968) have not
received much attention, except few similar studies (Deka et al. 2012, Sarma & Das 2012). Therefore the
present study deals with the species composition and other community attributes of undisturbed and disturbed
Sal forest of Goalpara District, Western Assam, Northeast India.
MATERIAL AND METHODS
The study was conducted in undisturbed and disturbed Secondary Sal forest located in Goalpara District,
Western Assam, Northeast India (Fig. 1). The geographical location of Goalpara District is between latitude 25
53'26 30' N and longitude 90 07'91 05' E. The vegetation was analysed by delimiting a total of five 0.1
Figure 1. Location of the study area in Goalpara District, Western Assam, Northeast India.
hectare quadrats randomly in each undisturbed and disturbed Sal forests. The girth of all the trees ( 10 cm
GBH) within the sampling area were measured at breast height (i.e. 1.37 m above the ground) and identified.
The climate is damp and warm humid and average annual rainfall of last five-year period (20082012) was
2173.02 mm yr-1
(Hydromet Division 2013).
Quantitative analysis of tree vegetation for Density and Basal area were done by following Misra (1968).
The importance value index (IVI) is the sum of relative density, relative frequency and relative dominance.
Shannon-Wiener diversity index (Shannon & Wiener 1963) was calculated from the IVI values using the
formula -
H =
-
Rabha (2014) 1(3): 1621 .
www.tropicalplantresearch.com 18
Where, is the proportion of individuals of species and total number of individuals all the species
( /N).
Concentration of dominance (cd.) was measured by Simpson index (Simpson 1949).
Cd. =
Where, is same as Shannon-Wiener diversity index.
A disturbance index for each forest site was calculated following Kanzaki & Kyoji (1986), Pandey & Shukla
(2001) and Borah et al. (2014). The disturbance index (DI) was calculated as the basal area of cut trees
measured at the ground level expressed as fraction of total basal area of all trees:
DI % = Basal area of cut stumps
100 Total basal area (cut stumps basal area + Standing tree basal area)
RESULTS
Species richness of pure Sal forests is generally very poor. In the present study only 3 species belonging to
three families was recorded in undisturbed forests whereas 18 species representing 14 families in disturbed Sal
forests (Table 1). Disturbances might be responsible for arrival and establishment of new species in disturbed
Table 1. Cumulative results of the undisturbed and disturbed Sal forest of Western Assam, Northeast India.
Parameter Undisturbed Disturbed
Species number 3 18
Family number 3 14
Density (tree ha-1
) 410 306
Basal area (m2 ha
-1) 26.40 12.90
Shannon index 0.73 2.05
Simpson index 0.60 0.25
Disturbance index (DI %) 7 51
Sal forests besides its high resilience capacity. The density and basal area of the tree species were significantly
lower in the disturbed forests than the undisturbed forests. The encountered density as well as basal area was
410 tree ha-1
and 26.40 m2 ha
-1 in undisturbed and 306 tree ha
-1 and 12.90 m
2 ha
-1 in disturbed forests
respectively (Table 1). Disturbance index indicated the degree of disturbance and found high (51%) in disturbed
forests and less (7%) in undisturbed forests (Table 1). Shorea robusta was found dominant in both undisturbed
and disturbed forests based on IVI score (Table 2). IVI score of each species in both forest types are shown in
Table 2.
In each forest type distribution of density and basal area in different GBH classes was shown in figure 2. In
undisturbed forests maximum density (30%) was recorded in 7090 cm GBH class and overall 78% density in
middle girth classes (50 cm to 130 cm GBH class) evidenced the post mass regeneration of that particular forest.
In disturbed forests maximum density (45%) was recorded in lowermost i.e. 1030 cm girth class and it
drastically decrease in successive girth classes hints its past disturbance history and the resilience capacity.
Density of other species was found high in disturbed Sal forests especially in lower girth class (Table 3).
Diversity index was comparatively more in disturbed forests than undisturbed forests (Table 1).
Figure 2. Girth class distribution of tree species in Sal forest: A, undisturbed; B, disturbed.
-
Rabha (2014) 1(3): 1621 .
www.tropicalplantresearch.com 19
Table 2. IVI score of each species in undisturbed and disturbed Sal forests of Western Assam, Northeast India.
S.No. Species name Undisturbed Disturbed
R.De R.Fr. R.Do. IVI R.De R.Fr. R.Do. IVI
1 Aegle marmelos (L.) Corr. 1.31 4.44 0.47 6.22 - - - -
2 Alstonia scholaris (L.) R.Br. 1.31 4.44 0.09 5.84 - - - -
3 Artocarpus chama Buch.-Ham. 0.65 2.22 0.14 3.02 - - - -
4 Callicarpa arborea Roxb. 2.61 6.67 7.75 17.03 - - - -
5 Dillenia indica L. 0.65 2.22 0.21 3.08 - - - -
6 Dillenia pentagyna L. 3.92 8.89 2.17 14.98 - - - -
7 Ficus religiosa L. 0.65 2.22 3.73 6.61 - - - -
8 Holarrhena pubescens (Buch.-
Ham.) Wall. ex G.Don 0.65 2.22 0.02 2.90 - - - -
9 Litsea monopetala (Roxb.) Pers. 3.92 8.89 1.26 14.07 - - - -
10 Mallotus ferrugineus (Roxb.)
Muell. Arg 3.27 8.89 1.09 13.24 - - - -
11 Mitragyna rotundifolia (Roxb)
O. Kuntze 1.96 4.44 0.31 6.72 - - - -
12 Shorea robusta Gaertn. 62.09 11.11 71.25 144.45 94.14 41.66 90.22 226.04
13 Schima wallichii (DC) Kuntze 7.19 11.11 8.22 26.52 3.41 33.33 5.53 42.27
14 Spondius pinnata 1.96 4.44 0.31 6.72 - - - -
15 Streblus asper Lour. 1.31 2.22 0.03 3.56 - - - -
16 Sterculia villosa Roxb. 2.61 4.44 0.62 7.68 - - - -
17 Terminalia bellirica (Gatertn.)
Roxb. 2.61 6.67 2.17 11.45 2.43 25.00 4.24 31.68
18 Toona ciliata M. Roem. 1.31 4.44 0.17 5.92 - - - -
Total 100 100 100 300.00 100 100 100 300.00
*R.De.= Relative density; R.Fr.= Relative frequency; R.Do.= Relative dominance; IVI= Importance Value Index.
Table 3. Density of Sal and other species in different girth class in undisturbed and disturbed Sal forest of Western Assam,
Northeast India.
GBH Class (cm) Species Density (tree ha
-1)
Undisturbed Disturbed
10-30 Sal 40 72
Other species 8 66
30-50 Sal 8 18
Other species 2 14
50-130 Sal 322 76
Other species 12 24
>130 Sal 16 30
Other species 2 6
DISCUSSIONS AND CONCLUSION
In present study only 3 species was found in undisturbed Sal forests agreement with the study carried out by
Stainton (1972) in Pure Sal forests of Nepal. More species number (18 species) in disturbed Sal forests might be
due to the anthropogenic disturbances which favour arrival and establishment of new species. In the present
study overall species number is quite low compare to the other studies reported from different part of Northeast
India (Uma Shankar 2001, Lalfakawma et al. 2009, Deka et al. 2012, Sarma & Das 2012, Dutta & Devi 2013).
The density of undisturbed forests was found 410 tree ha-1
and it is comparable to other studies done in different
Sal forests of the country such as 294559 tree ha-1 in Central India (Jha & Singh 1990), 484 tree ha-1 in Eastern
Himalaya, Meghalaya (Uma Shankar 2001), 408 trees ha-1
in Gorakhpur, India (Padey & Shukla 2003), 438 tree
ha-1
in moist Sal forests of West Bengal, India (Kushwaha & Nandy 2012), 422 tree ha-1
in Doboka reserve
forest, Assam, NE India (Dutta & Devi 2013). Comparatively less density in disturbed forests especially >50 cm
GBH class trees (136 tree ha-1
in disturbed against 340 tree ha-1
in undisturbed forests) might be due to the
various anthropogenic disturbances (Table 2). In the present study the basal area was recorded 26.40 m2 ha
-1 in
undisturbed and 12.90 m2 ha
-1 in disturbed Sal forests. Similar basal area (729 m2 ha-1) was reported from Sal
forest of Central India (Jha & Singh 1990). High density of other species in disturbed forests might be due to the
canopy gaps resulted from the disturbances. Disturbances enabled increased light intensity and ultimately
change the environmental condition make favourable for other lights demanding successional species (such as
-
Rabha (2014) 1(3): 1621 .
www.tropicalplantresearch.com 20
Schima wallichii, Callicarpa arborea etc.) leading towards mix forest communities. Species richness of
disturbed forest is a cumulative outcome of differential responses of species to disturbances (Sagar et al. 2003).
Kushwaha & Nandy (2012) reported that climatic conditions-mainly the rainfall, disturbance regimes and the
management practices influenced the species composition and community structure of Sal forests while in the
present study differences occur mainly because of the disturbance regimes.
Sal is a very important tree species and usually harvested for its timber. The Sal forests of Goalpara district
of Assam were exposed to different intensities of fire and anthropogenic disturbances in the past. Sarma & Das
(2012) stated that Sal forests of Western Assam has been facing great biotic pressures such as illegal felling,
firewood collection, encroachment of peripheral areas leading to pure Sal forests to mix forests which was also
reflected in the present study. Weeds and creeper also greatly influenced the regeneration of Sal forests. The
major threats such as illegal tree felling, firewood collection, encroachment of peripheral areas might be due to
the inadequate conservation strategy, negligence of concerned forest departments. The ongoing disturbances, if
not control then these undisturbed pure Sal forests may degrade and convert to the mix forests in the very near
future.
ACKNOWLEDGEMENTS
Author is thankful to the forest department of Goalpara district for permission and support during the
fieldwork.
REFERENCES
Ahmed M & Medhi D (2005) Encroachment causes shrinkages of forests in Goalpara district, Assam. In: Kumar
A (ed) Environmental Biology S.B. Nangia A.P.H. Publishing Corporation, New Delhi, pp. 167171.
Borah N, Devi AF, Garkoti SC, Das AK & Hore DK (2014) Structural and compositional variations in
undisturbed and disturbed tropical forests of Bhuban hills in south Assam, India. International Journal of
Biodiversity Science, Ecosystem Services and Management 10: 919
Champion HG & Seth SK (1968) A Revised Survey of the Forest Types of India. Govt. of India publications,
New Delhi.
Chauhan PS, Negi JDS, Singh L & Manhas RK (2008) Regeneration of Sal forests of Doon Valley. Annals of
Forestry 16 (2): 178182.
Chitale VS & Behera MD (2012) Can the distribution of Sal (Shorea robusta Gaertn. f.) shift in the northeastern
direction in India due to changing climate? Current Science 102(8): 11261134.
Deka J, Tripathi OP & Khan ML (2012) High dominance of Shorea robusta Gaertn. in alluvial plain Kamrup
Sal forest of Assam, N. E. India. International Journal of Ecosystems 2 (4): 6773.
Dutta G & Devi A (2013) Plant diversity and community structure in tropical moist deciduous sal (Shorea
robusta Gaertn.) forest of Assam, northeast India. Journal of Environmental and Applied Bioresearch 1 (3):
16.
Gautam KH & Devoe NN (2006) Ecological and anthropogenic niches of Sal (Shorea robusta Gaertn. f.) forest
and prospects for multiple-product forest management- a review. Forestry 79: 81101.
Hydromet Division (2013) Hydromet division, India meteorological department. Available from:
http://www.imd.gov.in/section/hydro/distrainfall/webrain/assam/goalpara.txt. (accessed: 19 Sep. 2014).
Jha CS & Singh JS (1990) Composition and dynamics of dry tropical forest in relation to soil texture. Journal of
Vegetation Science 1: 609614.
Kanzaki M & Kyoji Y (1986) Regeneration in subalpine coniferous forests: mortality and pattern of death of
canopy trees. The Botanical Magazine Tokyo 99: 3752.
Kushwaha SPS & Nandy S (2012) Species diversity and community structure in Sal (Shorea robusta) forests of
two different rainfall regimes in West Bangal, India. Biodiversity and Conservation 21: 12151228.
Lalfakawma, Roy S, Vanlalhriatpuia K & Vanalalhluna PC (2009) Community composition and tree population
structure in undisturbed and disturbed tropical semi-evergreen forest stands of north-east India. Applied
Ecology and Environmental Research 7: 303318.
Lawes MJ, Joubert R, Griffiths ME, Boudreau S & Chapman CA (2007) The effect of the spatial scale of
recruitment on tree diversity in Afromontane forest fragments. Biological Conservation 139: 447456.
Misra R (1968) Ecology Workbook. Oxford & IBH Publication co., New Delhi.
Padey SK & Shukla RP (2001) Regeneration strategy and plant diversity status in degraded Sal forests. Current
Science 81: 95102.
-
Rabha (2014) 1(3): 1621 .
www.tropicalplantresearch.com 21
Padey SK & Shukla RP (2003) Plant diversity in managed Sal (Shorea robusta Gaertn. f.) forest of Gorakhpur,
India: species composition, regeneration and conservation. Biodiversity Conservation 12: 22952319.
Qureshi IM, Shrivastava PBL & Bora NKS (1968) Sal (Shorea robusta) natural regeneration De-Novo effect of
soil working and weeding on the growth and establishment. Indian Forester 94: 591598.
Rautiainen O & Suoheimo J (1997) Natural regeneration potential and early development of Shorea robusta
Gaertn. f. forest after regeneration felling in the Bhabar-Terai Zone in Nepal. Forest Ecology and
Management 92: 243251.
Sagar R, Raghubanshi AS & Singh JS (2003) Tree species composition, dispersion and diversity along a
disturbance gradient in a dry tropical forest region of India. Forest Ecology and Management 186: 6171.
Sarkar M & Devi A (2014) Assessment of diversity, population structure and regeneration status of tree species
in Hollongapar Gibbon Wildlife Sanctuary, Assam, Northeast India. Tropical Plant Research 1(2): 2636.
Sarma SK & Das RK (2012) Community Structure of Sal (Shorea robusta, Gaertn.f) Forests of Western Assam,
India. The Botanica 59-61: 6777.
Shannon CE & Wiener W (1963) The Mathematical Theory of Communication. University of Illinois Press,
Urbona, USA.
Simpson EH (1949) Measurement of diversity. Nature 163: 688.
Soni RC (1961) Recent trends in Sal natural regeneration techniques with particular reference to B3 Sal. Proc.
Silva. Conf., Dehra Dun.
Stainton JDA (1972) Forests of Nepal. John Murray, London.
Uma Shankar (2001) A case of high tree diversity in a Sal (Shorea robusta) dominated lowland forest of Eastern
Himalaya: Floristic composition, regeneration and conservation. Current Science 81: 776786.
Upreti SDK & Nayaka S (2005) Shorea robusta-an excellent host tree for lichen growth in India. Current
Science 89(4): 594595.
-
www.tropicalplantresearch.com 22 Published online: 31 October 2014
ISSN (E): 2349 1183 ISSN (P): 2349 9265
1(3): 2226, 2014
Research article
Comparative evaluation of nutritional, biochemical and
enzymatic properties of the mycelium of two Pleurotus species
Ashutosh Rajoriya1, Anuradha Panda
2 and Nibha Gupta
1*
1Plant pathology and Microbiology division, Regional Plant Resource Centre, Bhubaneswar-751015, Odisha
2MITS School of Biotechnology, Bhubaneswar, Odisha
*Corresponding Author: [email protected] [Accepted: 20 October 2014]
Abstract: Aim of the present studies focuses on nutritional, antioxidant and extracellular
enzymatic activity of mycelium of Pleurotus sajor-caju and Pleurotus florida. Results shows that
both of the mushroom mycelium possess multiple nutritional, antioxidant components along with
good extracellular enzymatic activities. Methanolic extract of Pleurotus sajor-caju showed higher
phenolic and flavonoid content (1.010.57 mg gm-1
and 0.140.01 mg gm-1
) than Pleurotus florida
(0.450.05 and 0.110.01 mg gm-1
). A high alkaloid content was exhibited in P. sajor-caju than P.
florida, apart from the antioxidant components. P. sajor-caju showed high protein and
carbohydrate content i.e. 10.551.62 mg gm-1
and 32.167.16 gm 100gm-1
respectively, as
compared to P. florida which showed less amount of protein and carbohydrate content (8.50015
mg gm-1
and 8.301.09 gm 100gm-1
). Enzymatic screening showed good activity of amylase and
lipase where as Xylanase and protease activity in both the mushroom mycelium was negative.
Overall studies revealed that both the mushroom mycelium are potential source of antioxidants and
extracellular enzymes, especially flavonoids, amylase and lipase.
Keywords: Pleurotus - Mycelium - Nutritional - Antioxidants - Enzymatic.
[Cite as: Rajoriya A, Panda A & Gupta N (2014) Comparative evaluation of nutritional, biochemical and
enzymatic properties of the mycelium of two Pleurotus species. Tropical Plant Research 1(3): 2226]
INTRODUCTION
Wild edible mushroom have been integrated part of the diet, especially among rural, urban dwellers and
tribal people. Some of the common edible mushrooms, which are predominantly consumed in India are
Pleurotus sajor-caju, P. florida, P. platypus, P. djamor, Volvariella volvacea and Calocybe indica (Pan et al.
2008; Ramkumar et al. 2010). Pleurotus species is known as oyster mushrooms, which are widely spread
saprophytic macrofungi and distributed throughout the temperate and tropical forests of the world (Gunde-
Cimerman 1999). Oyster mushrooms are now in second rank among the cultivated mushrooms in the world
(Chang 1991) and are known to have potent antitumor, antimicrobial activities (Zhang et al. 1994; Gerasimenya
et al. 2002). Pleurotus sp are rich in minerals (Ca, P, Fe, K and Na) and vitamin C, B-complex (alarrmak
2007). Apart from the different nutritional and antioxidant components mushroom mycelium possess different
enzymes (Nonaka et al. 1997; Bose et al. 2007; Kadimaliev et al. 1998). Pleurotus is known for the different
cellulolytic and amylolytic enzymes (Sawiska & Kalbarczyk 2011; Jonathan & Adeoyo 2011). Recently
Pleurotus ostreatus and P. sajor-caju is characterized for the protease activity (Choi & Shin 1998; Ravikumar et
al. 2012). In Odisha mainly oyster mushroom Pleurotus sajor-caju and Pleurotus florida are grown
commercially. Both of them are liked by local people on account of unique characteristic of aroma and taste. In
the present work, this was taken into the consideration because reports suggests that fruit body of both of the
species possess good nutritional and antioxidant components along with industrially important enzymes and
since mycelium is the miniature of fruit body, therefore same behaviour was expected from the respective
mushrooms, hence it intended to evaluate the mushrooms nutraceuticals (Nutritional and Pharmaceutical)
potential.
-
Rajoriya et al. (2014) 1(3): 2226 .
www.tropicalplantresearch.com 23
MATERIAL AND METHODS
Nutritional analysis
Protein estimation was done by the method given by Bradford (1976). Estimation of carbohydrates was
carried out by following phenol sulphuric acid method (Dubois et al. 1956; Hedge & Hofreiter 1962). Reducing
sugars in the mycelium was done by following dinitrosalicylic acid method (Miller 1972). Non reducing sugar
was calculated by following the formula of Nazarudeen (2010).
Antioxidant analysis
One gm of fresh mycelium sample was disintegrated with 10 ml of methanol. Samples were stirred for 15
minutes for effective extraction and centrifuged at 3000 rpm for 20 minutes. Supernatants were referred as
methanolic extract and kept at 4 C until analysis (Puttaraju et al. 2006). The DPPH activity was estimated in the
methanolic extracts by colorimetric method (Chan et al. 2007). Ascorbic acid equivalent Antioxidant Capacity
(AEAC) was calculated by calibrating the value of above absorbance in standard ascorbic acid curve and
expressed in mg per gram of dried sample. Ferric Reducing Antioxidant Power (FRAP) assay was done by
following the method of Benzie & Strain (1996) and Athavale et al. (2012) and. The total phenolic content in
the mycelium were determined through Folin-phenol method with slight modifications (Singleton & Rossi
1965). The flavonoid content of sample was estimated by using aluminium chloride colorimetric technique and
flavonoid content was expressed in terms of mg quercetin equivalents per gram of extract (Chang et al. 2002).
The concentration of -carotene and lycopene in mushroom mycelium extracts was estimated
spectrophotometrically (Nagata & Yamashita 1992; Barros et al. 2007). Alkaloid content in the mushroom
mycelia was quantified spectrophotometrically (Srividya & Mehrotra 2003). Tannin content was estimated in
the sample by Folin denis reagent tannic acid was served as standard and expressed in mg gm-1
(Schanderl
1970).
Extracellular enzymatic activity
i) Amylase activity: All the mushroom mycelium was screened for the extracellular amylase activity for
which starch agar media was used. After the appreciable amount of the growth in plates they were
flooded with 1% iodine solution. Clear zone around the mycelial growth was recorded for the starch
hydrolysis activity.
ii) Cellulase activity: The medium containing 0.5% sodium salt of carboxymethylcellulose was used for the
tests. After the mycelial colonization plates were flooded with congo red solution (0.2%) and washed
with 1M NaCl solution followed by the incubation period of 15 minutes.
iii) Lipase activity: Spirit blue agar media was used for the screening of lipase activity. After the requisite
amount of growth of mushroom mycelium a clear zone or precipitate was observed for the positive
organism.
iv) L-Asparaginase activity: For screening of L- Asparaginase activity, medium containing 1% L- asparagine
was used where L-asparagine served as an active ingredient, after the mycelial growth plate was flooded
with Nesslers reagent. Plates showing pink coloration after the addition were recorded as extracellular
L- asparaginase producer.
v) Protease activity: Gelatin agar media was used for the screening of protease producing organism, for
which centre inoculation was done, after the incubation of 10 days plates were flooded with the reagent
containing 15% HgCl2 and 20% HCl.
vi) Xylanase activity: Medium containing xylan was used for the screening of Xylanase activity in mushroom mycelium. After the appreciable growth in the plate it was flooded with 0.1% Congo red,
incubated for 30 minutes and washed with 1M NaCl subsequently. Plate was observed for the formation
of clear zone for the production of Xylanase enzyme.
RESULTS AND DISCUSSION
In the present studies moderate to high nutritional components and antioxidant activities with varying levels
of phenolics, proteins and alkaloids were recorded in the two species of Pleurotus (Table-1). Relatively higher
amount of the protein content (10.551.62 mg gm-1
and 8.500.15 mg gm-1
) in both of the species was observed
as compared to the other species of Pleurotus as reported by Jean-Phillip (2005). Carbohydrate content in the
Pleurotus sajor-caju and Pleurotus florida was 32.16 and 8.30 gm 100gm-1
, respectively which was less than
the cultivated variety of Pleurotus as reported by Paz et al. (2012) but much more than the reports of Boda et
al. (2012). Pleurotus along with many other types of edible mushrooms have been known as a potent source of
-
Rajoriya et al. (2014) 1(3): 2226 .
www.tropicalplantresearch.com 24
nutrients as well as natural antioxidants. Findings from this research showed that fungal mycelia studied have
antioxidant capacity where FRAP and DPPH free radical scavenging activities assay showed a remarkable
difference between both the species. P. sajor-caju showed higher DPPH scavenging activities than P. florida i.e.
Table 1. Nutritional components and antioxidant activities of Pleurotus spp.
S. No. Parameters P. sajor-caju P. florida
1 Protein (mg/gm) 10.551.62 8.500.15
2 Carbohydrates (gm/100gm) 32.167.16 8.301.09
3 Red. Sugars (mg/gm) 24.371.04 12.911.51
4 Non Red. Sugars(gm/100gm) 29.727.09 7.001.02
5 DPPH scavenging (%) 45.530.01 9.95 1.14
6 AEAC(mg/gm) 0.101.69 0.020.00
7 FRAP (mg AEAC/gm) 0.790.10 0.060.01
8 Phenolics (mg/gm) 1.010.57 0.45 0.05
9 Flavonoids (mg/gm) 0.140.01 0.11 0.01
10 Beta carotene (mg/gm) 0.0380.012 0.0180.005
11 Lycopene (mg/gm) 0.0160.001 0.0070.002
12 Tannins (mg/gm) 5.180.64 4.480.86
13 Alkaloids (mg/gm) 0.490.01 0.470.08 DPPH- 2, 2-Diphenyl-1-picryl hydrazyl
AEAC- Ascorbic acid Equivalent Antioxidant Capacity.
FRAP- Ferric Reducing Antioxidant Power
(45.530.01%) and (9.95 1.14%) along with their corresponding AEAC value which was 0.101.69 mg gm-1
and 0.020.00 mg gm-1
, respectively. Phenolic and flavonoid content in both of the species confirms the study
of Vamanu (2012) and Jeena et al. (2014) in P. ostreatus. High amount of - carotene (0.0380.012 mg gm-1)
and lycopene (0.0180.005 mg gm-1
) content was recorded in P. sajor-caju where as comparatively less amount
of the same was recorded in P. florida. Presence of -carotene and lycopene was less as compared to the
investigations of Pal et al. (2010). Alkaloids are responsible for different cytotoxic and antimicrobial properties
(Ozcelik et al. 2011) Present study revealed the high amount of alkaloid was recorded in P. sajor-caju
(0.490.01 mg gm-1
) and P. florida (0.470.08 mg gm-1
). Tannins are responsible for different biological
activities such as antioxidant, antimicrobial and antitumor activities (Yoshizawa et al. 1987; Yoshida et al.
1989; Yoshida et al. 2009). Tannin content in P. florida and P. sajor-caju ranged from 4.48-5.18 mg gm-1
.
Comparatively P. sajorcaju, exhibited better scavenging of free radicals including high levels of protein,
carbohydrate, reducing sugars, phenol along with both FRAP and DPPH scavenging activities than P. florida. In
the present studies of the enzymatic activity of these mushroom mycelium, P. florida showed higher amylase
and lipase activity than P. sajor-caju, both the species were negative for the Xylanase and prote