ISSN 1021-4437, Russian Journal of Plant Physiology, 2008, Vol. 55, No. 6, pp. 808–813. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © K.R. Bhatt, V.S. Thaker, 2008, published in Fiziologiya Rastenii, 2008, Vol. 55, No. 6, pp. 895–900.
Seed as a rich source of many hormones, is known
to be essential for normal development of fruit; the size
and shape of many fruits being determined by seed
number and distribution . GA is thought to be a lim-
iting factor controlling the seed growth . It was
observed that GA level remained high in immature
seeds and decreased during seed maturation ; how-
ever, study on role of endogenous GA during seed
development especially in cotton is scarce. By manipu-
lating physiological processes in cotton seed, it may be
possible to increase the cotton yield.
Despite many advances in recent years, many ques-
tions related to seed development remained unan-
swered. Application of GA suggested that GA-induced
growth responses are regulated by the modulation of
GA concentration in cells and by altering the ability of
the cells to respond to this change [4, 5]. In the present
This text was submitted by the authors in English.
study, an attempt was made to evaluate the endogenous
level in kernel and seed coat as related to seed
MATERIALS AND METHODS
(G. Cot) varying in their seed dry
weight (91 mg/seed and 65 mg/seed at maturity, respec-
tively) were taken for this study.
Certiﬁed seeds were purchased
from Solar Agro-Biotech Co. from Rajkot. Seeds were
grown during 2003–2005 in botanical garden at Sau-
rashtra University, Rajkot (20.58–23.08 north latitude
and 70.20–71.40 east longitude). Seeds were assorted
for uniform size, soaked in water for 3 h, and sown at
the soil depth of about 1 cm. Seedling growth was mon-
itored and healthy seedlings with strong vigor were
allowed to grow further. Cultivation practices including
irrigation, application of fertilizers, insecticides etc.
were conducted to optimize the yield as described by
Thaker et al. .
On the day of anthesis, each
ﬂower was tagged and healthy bolls were harvested for
Relationship between Gibberellic Acid and Water Amount
in the Cotton Seed
K. R. Bhatt and V. S. Thaker
Department of Biosciences, Saurashtra University, Rajkot 360 005, India;
fax: +91–0281–2576802; e-mail: firstname.lastname@example.org
Received January 12, 2007
—The role of endogenous GA
and its application to seed development in two cotton genotypes
Hybrid-6 (H-6) (big seeds) and Gujarat cotton 13 (G. Cot) (small seeds) was studied. Kernel and seed coat were
subjected to growth analysis in terms of dry weight, water amount, and rates of dry matter accumulation and
water uptake. H-6 kernel had manifold higher dry weight and water amount than G. Cot. Seed coat of both gen-
otypes had similar dry weight at maturity, but the maximum rates of dry matter accumulation and water uptake
were distinctly higher in H-6. According to growth analysis, development of seed kernel and coat was subdi-
vided into four phases, i.e., cell division, cell elongation, dry matter accumulation and maturation. Endogenous
level was estimated in kernel and seed coat by indirect ELISA using antibodies raised against GA
amount per seed components was higher in the seed kernel of H-6 than of G. Cot, except 33 and 36 days after
anthesis in kernel. H-6 seed coat had the higher amount of GA
during cell division phase than that of G. Cot.
Close correlation between in vivo GA
level and water amount was recorded in both seed components. With
+ NAA treatments in ovule culture, higher promotion in dry weight, water amount and seed size
was noted in G. Cot than in H-6 suggesting that G. Cot is more deﬁcient in endogenous GA
. The greatest stim-
ulation of parameters studied was obtained in ovule culture with GA
+ NAA. When GA
+ NAA was
applied, initial signiﬁcant difference in water amount and seed size was nulliﬁed. Data presented in this study
indicated that GA
regulates cell expansion through the water uptake by cotton seed.
Key words: Gossypium hirsutum - Gossypium arboreum - dry matter accumulation - immunoassay - GA
nel - seed coat - ovule culture
: DMA—dry matter accumulation, DMF—dimethyl-
formamide, DPA—days post anthesis, G. Cot—Gujarat cotton-