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  • Seedling characters for correlation of some species of CohortUnisexuales (sensu Bentham and Hooker) in the Forest Patches

    of Dakshindinajpur, West Bengal

    P. Kamilya and Ayan DasDepartment of Botany, Balurghat College, Balurghat 733101, Dakshindinajpur, West Bengal, India

    E-mail: pkamilya.in@gmail.com & logangenex@gmail.com

    [Received 31.10.2014; Revised 19.12.2014; Accepted 24.12.2014; Published 31.12.2014]

    AbstractSeedling morphology of twenty-four taxa of the families (= natural orders) Euphorbiaceae andUrticaceae of the order (= cohort) Unisexuales (sensu Bentham & Hooker 1862 1883) havebeen studied from different forest patches of Dakshindinajpur District of West Bengal. Theseseedlings are described on the basic parameters for characterization of seedlings. Correlation ofthe taxa has been shown using seedling characters with UPGMA method to understand whetherthis correlation has any connection with natural system of classification.

    Key words: Seedlings, Seedling characters, Correlation, Dendrogram

    INTRODUCTION

    Seedling development is an early juvenile stage in plants life cycle. Non-volatile morphologicalcharacters of seedlings are very important to understand this initial process of plant life cycle(Paria et al 2006). Different taxa within the same or different groups exhibit diversity in thisstage and on the basis of which correlation can be drawn to understand the variability in thenatural characters among them. Many workers like Naidu & Shah 1978; Sampathkumar1982; Balasubhramanyam & Swarupanandan 1986; Deb & Paria 1986; Kamilya & Paria1993a,b, 1997; Paria & Kamilya 1999; Paria et al. 1990, 2006; Kamilya 2011; Duke 1965,1969; De Vogel 1980; Bokdam 1977; Ng 1975; Popma & Bongers 1988; Guillermo et al.2001 and Zanne et al. 2005 have worked to understand the impact of seedling characters ontaxonomy. However, correlation among taxa on the basis of seedling morphology is rare intheir works. In this work, an attempt has been made to understand the numerical relationshipamong taxa depending on seedling characters of twentyfour species of which sixteen ofthe family Euphorbiaceae and eight of the family Urticaceae under the order Unisexuales(sensu Bentham & Hooker 18621883). Numerical analysis has been carried out on thebasis of their seedling characters to draw correlation among them. In addition, we tried tofind out whether this correlation matches traditional system or not.

    MATERIALS AND METHODS

    The study was conducted in different natural and seminatural forest patches of Dakshindinajpurdistrict of West Bengal during August, 2013 to September, 2014. The total forest area in thedistrict is 2.95 sq km (Mitra & Mukherjee 2013) with mean annual rainfall 1847.8 mm andmean annual temperature varying from 23 29 C. The vegetation is mostly semi-deciduoustype (Kamilya 2011).

    Pleione 8(2): 416 - 426. 2014. ISSN: 0973-9467 East Himalayan Society for Spermatophyte Taxonomy

  • Seeds and seedlings are collected from their natural habitat in different forests atdifferent times. The seeds are sown in garden of the Department of Botany, BalurghatCollege and seedlings were raised. The natural seedlings are then compared with the raisedones for identification. Herbarium sheets are made with the pressed and dried seedlings anddiagnosed following Duke 1965; Burger 1972; DeVogel 1980 and Paria et al. 2006. Seedlingsare then characterized and an artificial key to the taxa has been made for the identificationof seedlings in natural habitat.

    For statistical analysis, characters were considered in numerical form as shown inTableI. To understand the interrelationships among the taxa, a dendrogram has been createdusing DendroUPGMA software. DendroUPGMA makes clustering from a set of variablesfrom similarity or dissimilarity matrix using Unweighted Pair Group method with ArithmeticMean (UPGMA) algorithm (Garcia-Vallve 1999). The numerical characters are put in fastalike format and the system is run in Pearson coefficient to measure linear correlation betweenthe OTUs (Sneath & Sokal 1973). The outcome is in phylip format where mean branchdivergence value between the taxa is displayed from which finally produce the dendrogram.

    The seedlings are displayed in the form of field photographs with highlightedparacotyledons and first two leaves for some of the studied species [PLATE - I] and handdrawings for others [PLATE - II]. Their characters are shown in the form of numericals(Table I) with the related characters for each value below the table. The taxa are arrangedalphabetically in the table along with references to figure and voucher numbers. Thoughseedlings are described upto 7th to 10th leaves stage, but due to more prominent distinctivenature it was considered up to 1st two leaved stage only.

    RESULT

    The observations on the structure of seedlings and the result of the numerical survey hasbeen presented in Table 1. PLATES I & II presented the photographs and drawings of theseedlings under study.

    Based on the morphological characters a Key has been prepared to identify these seedlingsin natural conditions:

    Artificial Key to the seedling species (Key valid for taxa studied only):

    1. Seedlings phanerocotylar ........... 21a. Seedlings cryptocotylar ............. 222. Apex of paracotyledons other than retuse ... ........ 32a. Apex of paracotyledons retuse ..... 193. Hypocotyl strictly rounded; first 2 leaves always opposite ........ .......... 43a. Hypocotyl may be rounded or angular; first 2 leaves opposite or alternate .... 124. Apex of paracotyledons obtuse or shallowly sinuate, primary vein 1, 3 or 7; first 2

    leaves, elliptic, widely elliptic or obovate, base cuneate or rounded, venationcamptodromous ...................... .................... ................... ........ 5

    4a. Apex of paracotyledons rounded or truncate, primary veins 5; first 2 leaves orbicularor ovate, base peltate, cordate or truncate, venation actinodromous 9

    5. Paracotyledons elliptic, oblong or flabellate; tip of first 2 leaves obtuse or mucronate .. 65a. Paracotyledons ovate; apex of first 2 leaves acute Glochidion ellipticum

    P. Kamilya & Ayan Das 417

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    418 Seedling characters of some species of Cohort Unisexuales

  • P. Kamilya & Ayan Das 419

  • 6. Hypocotyl pubescent; number of primary veins in paracotyledons 3 or 7, venationactinodromous; first 2 leaves elliptic or widely elliptic, obtuse .... .... 7

    6a. Hypocotyl glabrous; number of primary veins in paracotyledons one, venationhyphodromous; first 2 leaves obovate, mucronate Breynia retusa

    7. Paracotyledons oblong or flabellate, apex shallowly sinuate; first 2 leaves widely elliptic;first internode pubescent or tomentose ................... ..... 8

    7a. Paracotyledons elliptic, obtuse; first 2 leaves elliptic; first internode glabrous ............ Antidesma acidum

    8. Paracotyledons oblong, slightly oblique, primary veins 5; base of first 2 leaves cuneate;first internode pubescent ................. .... Bridelia stipularis

    8a. Paracotyledons flabellate, not oblique, primary veins 7; base of first 2 leaves rounded;first internode tomentose ................... Bridelia tomentosa

    9. Hypocotyl glabrous; paracotyledons oblong, base rounded, apex rounded; base of first 2leaves peltate or cordate, apex rounded or acute, glandular hair present on the petiole;heteroblastic development present .... ................ ........ 10

    9a. Hypocotyl pubescent or sparsely pubescent; paracotyledons obovate, truncate, basecuneate; base of first 2 leaves truncate, apex acuminate, glandular hair not present;heteroblastic development absent ... ..................... ........... 11

    10. First 2 leaves orbicular, base peltate, apex rounded ..... Jatropha podagrica10a. First 2 leaves ovate, base cordate, apex acute Jatropha gossypifolia11. Hypocotyl sparsely pubescent; margin of first 2 leaves dentate; first internode round,

    tomentose ... ................. ................... Mallotus repandus11a. Hypocotyl densely pubescent; margin of first 2 leaves serrate; first internode angular,

    hirsute ..... ........................ ....... Mallotus philippinensis12. Apex of first 2 leaves acute, obtuse or acuminate, venation actinodromous or

    camptodromous ... ... ... ...... 1312a. Apex of first 2 leaves always acute, venation always camptodromous . 1713. Petioles of paracotyledons adaxially deeply concave, paracotyledons suborbicular or

    flabellate, apex shallowly sinuate or rounded, venation actinodromous; base of first 2leaves cuneate, attenuate, cordate or truncate, margin dentate or crenate dentate

    1413a. Petioles of paracotyledons dorsiventrally flattened dorsally shallowly channeled,

    paracotyledons oblong, apex obtuse, venation hyphomous; base of first 2 leavesrounded, margin serrate ............. ... ............... Trema orientalis

    14. Apex of paracotyledons shallowly sinuate; first 2 leaves elliptic, venationcamptodromous; first internode glabrous ... ... ....... 15

    14a. Apex of paracotyledons rounded; first 2 leaves ovate, venation actinodromous; firstinternode pubescent ...

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