Research Center for Agriculture and Natural Resources of East Azarbaijan, Tabriz, Islamic Republic of
Iran.
Abstract: (5874 Views)
In order to evaluate the physiological indices in relation to the screening of spring
safflower genotypes for drought tolerance and productivity, seed and oil yields and yield
components were measured for five genotypes including Local Arak, Local Esfahan, Sina,
KH23 – 57 and Goldasht. The study was conducted in a loam soil in East Azarbaijan, Iran,
during three successive years (2005-2007). Water treatments consisted of non-stressed and
water deficit imposed from flowering (80% flowering) to maturity. Several physiological
indices including relative water content (RWC), stomatal conductance (Kl), leaf
temperature, osmotic adjustment, and specific leaf weight (SLW) were measured.
Considering the significant decrease of seeds in capitulum, 1000 seeds weight, harvest
index (HI), seed and oil yields due to water deficit, it seems that drought decreased seed
and oil yields mainly via declining these components of yield. Since RWC and Kl decreased
and leaf temperature, osmotic adjustment, and SLW were increased significantly by water
deficit, therefore these indices could reflect the stress effects during seed filling period.
Among RWC, Kl, leaf temperature and osmotic adjustment, significant correlations were
seen. Also significant positive correlations were found among Kl, RWC and SLW with seed
and oil yield. Screening spring safflower genotypes by the abovementioned characteristics
may lead to economically acceptable yields under water deficit condition. Among the
genotypes, Goldasht, with 1,412 and 358 kg ha-1 seed and oil yields, respectively, had the
lowest yield, associated with lower values of RWC, Kl and osmotic adjustment. Other
genotypes had similar seed and oil yields, while Local Arak had the higher amounts of
seed and oil yields, associated with higher values of RWC, Kl and osmotic adjustment. It is
concluded that Local Esfahan, Sina, KH23-57, and especially Local Arak genotypes, can be
used for cultivation in Khosro Shahr and areas with similar climate (cold and semi-arid in
Koppen climate classification) under normal and late season drought conditions.
Received: 2011/01/18 | Accepted: 2011/01/18 | Published: 2011/01/18