ori, idit, zohar and zahov: tablestock and chipstock cultivars bred for adaptation to israel
TRANSCRIPT
Amer J of Potato Res (2001) 78:167-173 167
Ori, Idit, Zohar and Zahov: Tablestock and Chipstock Cultivars Bred for Adaptation to Israel
D. Levy 1, Y. Itzhak 1, E. Fogelman ~, E. Margalit 2, and R. E. Veilleux 3.
IDepartment of Vegetable Crops, Institute of Field and Garden Crops, The Volcani Center, ARO, Bet Dagan 50 250, Israel. 2Elite Enterprises, Sha'ar HaNegev, Shderot 80100, Israel.
~Department of Horticulture, Virginia Polytechnic Institute & State University, Blacksburg, Virginia, 24061. *Corresponding author: Tel: 540-231-5584; Fax: 540-231-3083; Email: [email protected].
ABSTRACT
The cul t ivars Ori, Idit , Zohar, and Zahov have been
bred specifically for adap ta t ion to the Med i t e ranean cli-
mate : Ori and Idi t a re ear ly t ab les tock cul t ivars , Id i t is
su i t ed for "min i p o t a t o e s " (20 to 35 mm in d i a m e t e r ) ;
Zohar is a midseason t a b l e s t o c k cui t ivar , and Zahov is
used as an ear ly chipstock cuitivar. The cul t ivars can be
grown in e i ther o f the two main seasons in the Medi ter-
r anean region: the spring season ( January through Ju ly )
and the win te r season (Sep t embe r through March). The
cul t ivars have rapid emergence and ear ly tuber set, they
are t o l e r an t to high t e m p e r a t u r e s and drought , and are
n o t suscept ib le to e x t e r n a l o r in te rna l defects . In f ie ld
e x p e r i m e n t s , Id i t y ie lds w e r e l ower t h a n the c u l t i v a r
checks (Alpha, Nicola, or Des i ree ) in six o f seven trials.
H o w e v e r , the a t t r a c t i v e a p p e a r a n c e o f t he sma l l ova l
tubers (20-35 mm in d i ame te r ) and the good a roma o f the
baked tubers are advantages. Yield o f Ori and Zohar occa-
s ionally exceeded those o f cul t ivar checks, and the i r yel-
lowish skin, e spec ia l ly in sandy soils, is an advan tage .
Yields and tuber dry m a t t e r con ten t o f the ear ly-matur ing
cul t ivar Zahov were s imilar to Hermes, a s t andard chip-
s tock cul t ivar commonly used in Israel. The ear ly matura-
t ion o f Zahov is desi rable to ex tend the harves t season.
RESUMEN
Los cul t ivares Ori, Idit , Zohar y Zahov han sido mejo-
r a d o s e s p e c i f i c a m e n t e p a r a a d a p t a r s e al c l i m a de l
Medi terr~neo: Ori e Idi t son cul t ivares precoces para uso
directo. Idi t es usado como "mini papa" (20 a 35 nun de
di~metro) ; Zohar es un cul t ivar de uso d i rec to de media
es tac i6n y Zahov es usado como un cul t ivar precoz para
Accepted for publication August 24, 2000. ADDITIONAL KEY WORDS: Cultivar development, heat tolerance, potato, processing, Solanum tuberosum.
prepara r hojuelas. Los cul t ivares c recen en cualquiera de
las dos es tac iones principales de la regi6n mediterr~nea:
p r imavera (de enero a ju l io) e invierno (desde se t iembre
has ta matzo) . Los cul t ivares t i enen r~pida emergencia y
tuber izac i6n temprana, son t o l e r an t e s a las al tas temper-
a turas y sequias y no son suscept ibles a defectos in te rnos
o externos . En exper imentos de campo, los rendimientos
de Id i t f u e r o n m~s bajos que los de cu l t iva res t e s t igos
(Alpha, Nicola o Des i r~e) en seis de s ie te pruebas . Sin
embargo, la apar iencia a t r ac t iva de los pequefios tub~r-
culos ovalados (20-35 mm de dL4metro) y el rico a roma de
los tub~rculos horneados cons t i tuyen una clara ventaja .
Los rend imien tos de Ori y Zohar exced ie ron en ocasiones
a los cu l t iva res tes t igos y su p ie l amar i l len ta , especial-
mente en suelos arenosos, es igua lmente una ventaja . Los
rendimien tos y contenido de ma te r i a seca de los tub~rcu-
los de m adu rac i6n t e m p r a n a de l cu l t i va r Zahov f u e r o n
s imi lares a Hermes , un cu l t iva r e s t~ndar para e l abo ra r
ho jue la s , de uso comtln en I s rae l . La t e m p r a n a madu-
raci6n de Zahov es conveniente porque puede ex tende r se
has ta la t emporada de cosecha.
BACKGROUND
Numerous potato cultivars, mostly S o l a n u m tuberosum L.
ssp. tuberosum, have been bred in the temperate climates of
Europe and North America, where centers for potato breeding
and research have flourished (Love et al. 1998; Plaisted and
Hoopes 1989). The potato is considered to be adapted to cool
climates and to be adversely affected by high temperatures
(Borah and Milthorpe 1962; Hawkes 1978). Because of the recent
cultivation of potatoes in subtropical, semiarid, and arid regions
(Van der Zaag and Horton 1983), the need has arisen to breed
heat-tolerant cultivars (Sinunonds 1971). Although the modem
ssp. t uberosum is extensively adapted to the conditions prevail-
ing in temperate climates, namely moderate day temperatures,
cool nights and long days, certain genotypes have the capacity to
initiate tubers at high temperatures (Ewing et al. 1987; Reynolds
168 AMERICAN JOURNAL OF POTATO RESEARCH Vol. 78
and Ewing 1989) and exhibit relatively small yield losses in hot
seasons (Levy 1986a, b; Tal et al. 1994). It has also been possible
to select heat tolerant clones among seedlings of cultivated vari-
eties (Levy 1984). Apart from tuber initiation and growth, culti-
vars grown in Israel should be resistant to physiological tuber
disorders exaggerated in warm climates. These include tuber
deformation, "chain" tubers, sprouting, shortened dormancy,
internal heat necrosis, and elevated levels of alkaloids (Levy
1986a, b; Dimenstein et al. 1997). Tolerance to these disorders is
important in the selection of better-adapted cultivars.
In many Mediterranean countries, a potato crop can be
grown twice a year (double cropping), in the spring season and
in the autumn/winter season (Levy et al. 1986, 1990). In the
spring season, planting takes place during January or February
and harvesting during May, June, or July, 130-150 days after
planting. Due to prevailing high temperatures, harvest is con-
ducted after midnight and in the early morning.
Some of the tubers harvested in May and June are kept as
seed for the subsequent autumn/winter season, planted in Sep-
tember/October and harvested from December through Febru-
ary, 90-120 days after planting (but 70-90 days after planting for
mini-potatoes). Growers in these regions prefer cultivars that
are able to produce high tuber yields of good quality potatoes in
both seasons. This requires cultivars that can adapt to contrast-
ing climatological conditions (Levy et al. 1990): in the spring sea-
son, growth starts when temperatures are relatively low and
daylength relatively short, and the crop matures under increas-
Ing temperature, daylength and irradiation; in the autumn sea-
son, growth begins under relatively high temperature and long
daylength, whereas the crop matures under decreasing temper-
atures, daylength, and irradiation (Table 1). Daylength in Israel
(latitude 32030 ' N, longitude 35030 , E) ranges from 10 h 3 min on
December 21 to 14 h 15 min on June 21.
Potatoes in Israel are irrigated throughout the season.
Sprinkler irrigation is commonly used, and fertilizers are applied
through the irrigation system. The descriptions and data pre-
sented are for fully irrigated conditions. Irrigation amounts in
the spring season averaged between 625-720 ram, and in the
auttLmn/winter season between 340 and 400 mm. At each site,
the most commonly grown cultivars served as controls.
Ori and Idit were selected from seedlings grown from seed
of open-pollinated Desiree fruit collected in a commercial field
(Levy 1984). Zohar originated from a Desiree x LT7 cross (Levy
et al. 1991). Seeds were sown in speedling trays (Speedling Inc.,
Sun City, FL) containing peat and vermiculite (2:1 v/v) in a
glasshouse maintained at 30-35 C under 12 h day, and 20-22 C
during the nights. Irrigation was applied once or twice a day to
avoid drought stress. The seedlings were examined periodically
for tuberization by lifting each seedling gently and replanting it.
Seedlings that developed tubers were transplanted into 10-cm 2
plastic pots in a cool glasshouse for further development (Levy
et al. 1991). Zahov is a clone selected from seed of a complex
hybrid where the female parent was S. tuberosum cv Atlantic
and the male parent was S. andigena Juz. & Buk. P.I. 347773
haploid clone 13030 • [S. phureja Juz. & Buk. clone PP5 • S.
be~haultii Hawkes, P.I. 265858 clone 9] (Veilleux et al. 1997).
DESCRIPTION Ori
Ori is an early cultivar, earlier than Desiree, with good resis-
TABLE 1--Climatological data (1964-1979) f o r selected locations in Israel.
Besor Central Negev
Average monthly Mean daily Average monthly Mean daffy Temperature (C) evaporation temperature (C) evaporation
Month Maximum Minimum (mm) M a x i m u m Minimm'a (mm)
January 17.3 7.3 2.6 16.4 6.0 2.4 February 18.6 7.7 3.7 18.4 6.9 3.1 March 20.8 9.3 4.9 21.3 8.9 4.4 April 24.3 11.7 6.9 25.5 11.5 6.2 May 26.5 14.1 8.0 29.3 13.9 7.7 June 29.1 17.4 8.8 31.9 16.7 8.8 July 30.0 19.3 8.8 32.9 18.5 8.7 August 30.3 19.8 8.0 32.8 18.6 8.0 September 29.2 18. 7 6. 7 31.1 17.1 6.8 October 27.4 16.1 5.3 28.6 14.7 5.3 November 23.6 12.6 3.9 23.4 11.0 3.5 December 18.8 8.8 2.6 17.9 7.3 2.5
Coastal Plain
Average monthly Mean daffy temperature (C) evaporation
Maxiram~ Minimum (ram)
17.9 6.6 1.8 19.2 6.8 4 2.4 21.5 8.6 3.5 24.6 11.0 5.0 26.7 13.6 6.2 29.3 17.1 7.0 30.6 19.3 7.0 30.9 19.6 6.6 29.9 18.1 5.8 28.0 14.8 4.3 24.2 11.2 2.7 19.4 8.2 1.8
2001 LEVY, et al.: TABLESTOCK, CHIPSTOCK CULTIVARS FOR ISRAEL 169
tance to heat and drought. The plant habit is semi-erect with
sturdy stems and light anthocyanin pigmentation of the stem.
Leaves are snmll, dark green without anthocyanin pigmentation
and with fairly deep veins. The terminal leaflet is coalescent. The
inflorescence has a medium number of flowers and light antho-
cyanin in the bud. The corolla is medium sized and pale purple.
Tuber skin is buff colored with flaky surface and slightly ovate.
Eye depth is shallow, 8-12 eyes per tuber, predominantly at the
apical end. Tuber flesh is pale yellow. Dormancy is similar to or
slightly shorter than Desiree. Light sprouts are medium-sized, con-
ical, light red-purple at the base, the terminal bud fairly small,
closed and green.
Idit
Idit is an early cultivar, earlier than Desiree, with good resis-
tance to heat and drought. The plant is low and erect with sturdy
green stems. Leaves are small and dark green with deep veins
and no anthocyanin pigmentation. The terminal leaflet is coales-
cent. Inflorescences have a medium number of white flowers.
Tubers are long, slightly ovate with some pointed, buff colored
with flaky skin. Eyes are shallow, 6-10 eyes per tuber, predomi-
nantly at the apical end. Tuber flesh is pale yellow. Dormancy is
similar to or slightly shorter than Desiree. Light sprouts are
medium sized, narrow, conical with a light red pigmentation at
the base; terminal buds are small, green, and slightly open.
Z o h a r
Zohar is a medium-early cultivar, slightly earlier than
Desiree. Leaves are small and light green with no anthocyanin
pigmentation. The terminal leaflet is frequently coalescent. The
inflorescences have an average number of white flowers. Tubers
are long-oval with smooth yellow sldn and pale yellow flesh (Fig.
1). The eyes are shallow, 5-8 eyes per tuber, predominantly at
the apical end. Dormancy is similar to Desiree. Light sprouts are
medium sized, conical, and green. Terminal buds are small and
slightly open.
Zahov
Zahov is an early cultivar, earlier than Desiree and Hermes.
The plant has delicate stems, fairly spreading with palish green
leaves. The terminal leaflet is sometimes coalescent. The inflo-
rescence has a medium number of small white flowers. Tubers
are oval with smooth yellow skin and yellow flesh (Fig. 2). The
eyes are shallow, averaging 5-7 per tuber, and predominantly at
the apical end. Tuber dormancy is similar to Desiree and slightly
shorter than Lady Rosetta and Hermes.
C H A R A C T E R I S T I C S
All four cultivars exhibit early vine growth. The plants of
Ori and Idit are erect and compact. Zohar develops large haulms
170 AMERICAN JOURNAL OF POTATO RESEARCH Vol. 78
FIG URE 2. Tub ers o f Zahov grown in the w i n t e r s e a s o n in s a n d y - l o e s s so i l in Israel .
early in the season providing good ground cover, and Zahov has
intermediate haulm development.
Ori and Idit were compared to Desiree at various locations
in Israel in both winter and spring seasons. The locations pro-
v ided a range of growing condi t ions including the modera t e
coastal region, four arid regions in the Negev Desert (including
the sandy soil desert region of the Besot), and finally the Golan
Heights at 900 m above sea level, the only area where potato can
be grown during the summer in Israel. Ori outperformed the
control in three of the eight trials and had the same yield as
Desiree in Merom Golan (Table 2). Idit did not yield as well as
the cont ro l in six of the seven trials (Table 2); however , the
a t t ract ive oval shape of the tubers of 20-35 mm and the r ich
aroma of the baked tubers justify its release.
Zohar was tested at five different locations (Table 3). It out-
p e r f o r m e d Spunta, one of the mos t popula r cult ivars in the
Mediterranean region, had yields similar to Alpha, and slightly
higher yields than Santana and Nicola (Table 3). Desiree (red
skin) and Kennebec (round shape) had higher yields than Zohar;
howeve r , the a t t rac t ive ob long t u b e r shape and the br igh t
smooth yel low skin with shallow eyes of Zohar are preferable
and justify its release.
Table 4 shows yield, dry matter, and reducing sugar content
for Zahov at three locations. The yield of Zahov was similar to
that of Hermes, an important chipstock cultivar in Israel. Dry
matter content of Zahov was higher than Hermes and reducing
sugars were either not present or present at a low concentration,
as with Hermes (Table 4). On a scale of 1 (low quality) to 9 (best
quality), as evaluated by a panel of 30 persons, the taste, texture,
color, shape, appearance, and acceptance were respectively 8.2,
8.2, 8.4, 7.3, 7.2, and 8.1 for Zahov, compared to 8.0, 8.0, 8.2, 7.0,
TABLE 2--Fresh tuber yield (kg m 2) of Ori, Idit, and corresponding controls, under field conditions at various locations
and seasons in Israel.
Tuber yield (kg ra ~)
Place Year Season Soft type Ori Idit Control
Coastal Plain 1983/84 Winter Light loam 3.5 4.1 3.7 (Desiree) 1985 Spring 4.6 4.3 6.1 (Desiree) 1
Merom Golan 1985 Summer ~ Brown clay loam 6.6 5.6 6.6 (Desiree) ~ Northern Negev 1985 Spring Loess 3.9 3.2 5.0 (Desiree) 1
1986 Spring 4.2 3.9 4.9 (Alpha) 1 Central Negev 1987 Spring Loess 7.3 5.1 6.9 (Nicola) 1 Western Negev 1997 Spring Loess 9.2 7.8 (Desiree) 1 Besor 1999/00 Winter Sandy soil 4.3 3.9 3.9 (Nicola)
1Control seed tubers imported from Europe. 2Grown in.the summer season from April to September.
2001 LEVY, et al.: TABLESTOCK, CHIPSTOCK CULTIVARS FOR ISRAEL 171
TABLE 3---Fresh tuber yield (kg m-2) of Zohar under fleld conditions at f ive locations in different seasons in lsrael. The
control cultivar used at each location is given parentheticaUy.
Tuber yield (kg m 2)
Location Year Season Soil type Zohar Control
Central Negev 1995/96 Winter Loess 3.7 3.7 (Alpha) Northern Negev 1996/97 Winter Loess 5.0 3.2 (Spunta) Coastal plain 1996 Spring Light loam 5.0 5.9 (Kennebec) ~ Western Negev 1997 Spring Loess 5.7 7.8 (Desiree) l Northern Negev 1997/98 Winter Loess 3.4 4.0 (Desiree) Besor 1998/99 Winter Sandy soil 3.3 3.7 (Nicola) Besor 1998/99 Winter Sandy soil 4.8 4.7 (Santana) Besor 1999/00 Winter Sandy soil 4.1 3.9 (Nicola)
IControl seed tubers imported from Europe.
7.4, and 7.9 for Hernms. Zahov matures earlier than Hermes, an
advantage that allows extension of the harvest period.
For the winter season seed tubers are commonly produced
in Israel the preceding spring, i.e., harvested in June and kept at
6-8 C until planting in autumn (Levy et al. 1986). For the spring
season , however , s eed tube r s are general ly i m p o r t e d f rom
E u r o p e whe re ha rves t t akes p l ace the p r e c e d i n g a u t u m n
(August-September). Hence, when comparing spring yields in
Tables 2 and 3, the different physiological and chronological
ages of the seed tubers should be considered: seed of the local
cultivars was about 2 months older than for the control cuitivars
and may have affected vigour and yield. The high yield of Ori in
the trials in Central and Western Negev and in Besor indicate
maintenance of seed tuber vigour (Table 2).
Biotic and abiotic s t ress condit ions tend to enhance the
metabolism of alkaloids (Sinden and Webb 1974). In earlier stud-
ies, elevated levels of glycoalkaloids were measured in tubers
exposed to high temperatures (Dimenstein et al. 1997). Hence,
glycoalkaloid levels were assessed in tubers grown under field
condi t ions in both spring and win te r seasons (Table 5). Gly-
coalkaloid content in tubers of Zahov was higher than in tubers
of the other cultivars, which may be associated with the exotic
germplasm of its parents (Gregory 1984; Veilleux et al. 1997).
However, under these conditions, the glycoakaloid level of Zahov
did not reach the limit of 20 mg 100 g ~ tuber fresh weight.
Under common growing conditions in Israel, the appearance
of internal heat necrosis in the tubers is a prominent criterion for
discarding unsuitable cultivars and clones. In Ori, Idit, Zohar, and
Zahov, internal heat necrosis has been rare. However , under
severe stress conditions known to cause extensive internal necro-
sis in Atlantic, some necrosis nfight appear in Idit and Zahov.
USAGE
Ori and Zohar have good tuber appearance and no after-
cooking darkening, and thus are suitable for tablestock use. The
TABLE 4--Fresh tuber yields (kg m z), dry matter content (DM, %), and reducing sugars content (RS, %) of Zahov grown at
three locations, including both the winter and spring seasons in the Central Negev, in Israel.
Location Year Season Soil type
Central Negev 1996 Spring Loess Central Negev 1996/97 Winter Loess Western Negev 1996/97 Winter Loess Northern Negev 1997/98 Winter Loess Western Negev 1998/99 Winter Loess Western Negev 1998/99 Winter Sandy-Loess
~Control seed tubers imported from Europe.
Zahov Control
Yield DM RS Yield DM RS (kg m z) % % (kg m ~ ) % %
2.9 17.3 0.00 2.4 (Panda) ~ 16.4 0.00 2.4 3.4 (Lady Rosetta) 17.6 0.00 2.5 20.4 0.05 3.0 (Hermes) 20.1 0.05 2.6 18.5 0.05 4.0 (Desiree) 2.9 17.8 3.0 (Hermes) 17.2 0.00 2.8 17.4 0.00 2.8 (Hermes) 16.8 0.00
172 AMERICAN JOURNAL O F POTATO R E S E A R C H Vol. 78
TABLE 5--Content o f total glycoalkaloids (TGA, m g 100 g.1 tuber f resh weight + S.E.) in tubers o f f o u r n e w cultivars evalu-
ated in f o u r env ironments in Israel in both w in te r and spring seasons over several years.
TGA (mg 100 gl tuber fresh weight _+ S.E.) in cultivar
Location Year Season Ori Idit Zohar Zahov
Coastal Plain 1992/93 Winter 5.6 • 0.4 Coastal Plain 1993 Spring 8.4 • 0.5 Coastal Plain 1993/94 Winter Coastal Plain 1996 Spring Central Negev 1996 Spring Coastal Plain 1997 Spring Western Negev 1997 Spring 5.4 • 0.3 Coastal Plato 1998/99 Winter 8.8 • 0.1 Besot 1998/99 Winter Besor 1999 Spring
11.0• 9.4• 7.0•
5.2• 4.5•
8.3• 6.3• 3.5•
12.0• 7.4•
14.5• 12.7• 10.6• 6.8•
cul t ivars have a relat ively h igh dry m a t t e r c o n t e n t (18%-20%)
al lowing thei r use for h o m e m a d e f rench fries tha t are slightly
b r o w n due to the i r sugar conten t . The long oval s h a p e of Idit
m a k e s it sui table for p roduc t ion of mini po ta toes (or baby pota-
toes), 20-35 m m in diameter . Idit has except ional po ta to aroma,
especial ly w h e n baked. The pr imary use for Zahov is as an early
p rocess ing cult ivar due to i ts h igh specific gravity and at t ract ive
chip color and taste.
SEED AVAILABILITY
Small quanti t ies of seed are available for tes t ing pu rposes
f rom the Volcani Center, ARO (D. Levy).
ACKNOWLEDGMENTS
The authors acknowledge the impor tant cont r ibut ion of the
Uni ted States-Israel Binat ional Agricultural Research and Devel-
o p m e n t Fund (BARD) to the deve lopmen t of po ta to r e s e a r c h
and breeding in Israel. Cont r ibut ion of the Volcani Center, Bet
Dagan, Israel, No. 141/99 Agricultural Research Organization.
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