16. Physiological screening of cotton (Gossypium hirsutum L.) genotypes against drought tolerance

Abstract

Cotton is a vital fiber and oilseed crop badly affected by soil moisture deficit stress. Screening of cotton germplasm is a prerequisite to classify the cotton genotypes as a drought sensitive and tolerant. With the aim to separate the distinct genotypes, eight cotton genotypes (BH-190, Ali Akbar-802, NIAB-86, NIBGE-115, FH-942, IUB-13, MNH-886, and FH Lalazar) were grown under normal moisture (08 irrigations/ 28 acre inches) and moisture stress (03 irrigations at 60, 90 and 120 DAS/ water deficit of 15 inches) environments. The assessment was done through different physiological parameters (stomatal conductance, osmotic and water potential, photosynthetic rate, relative water contents and canopy temperature). Cell injury and yield were also evaluated. The experimental design was Randomized Complete Block Design (RCBD) in factorial way with three replicates. The data obtained was investigated statistically at 5% probability and Least Significant Difference (LSD) test was used to isolate the significant means (treatment). The results indicated that water stress adversely reduced the values of all the above stated parameters. The cotton genotype BH-190 had significantly greater (p<0.05) yield and physiological attributes and found extra water deficit stress tolerant. While cotton genotype FH Lalazar had least value of these attributes as compared to all remaining cotton genotypes and thus considered as water deficit stress sensitive genotype. So, it can be concluded from the results of this experiment that the physiological screening of low soil moisture stress tolerant varieties could be a superior way to mitigate impact of drought stress on the cotton cultivated in drought susceptible regions.

Keywords: Cotton (Gossypium hirsutum L.); Drought tolerant; Physiological; Screening

http://dx.doi.org/10.19045/bspab.2020.90017