Abstract

The presence of genetically based difference in drought stress tolerance is a key for breeding cultivars with enhanced tolerance to water stress by selection and breeding. In order to achieve such evidence inGossypium hirsutum, 90 genotypes were evaluated for growth and productivity traits in randomized complete block design (RCBD) with three replications. The genotypes were evaluated under well watered (W1) and water stressed conditions (W2). From the variance analysis, significant differences were detected among varieties for seed cotton yield, boll number, boll weight, number nodes and plant height. The data indicates that the numbers of formed bolls in water stressed were less than that in non-stress conditions, and significantly correlated with seed cotton yield. High heritability and high genetic advance was also found for certain traits. Some genotypes were ranked top on the basis of plant height and number of nodes, while others ranked well on the basis of seed cotton yield. Hence, to become clear of this difficulty, selection index was performed by giving an equal weight to all the growth and productivity traits studied. Index ranked all 90 genotypes from top to low and revealed that MNH-6070, MNH-552, SLS-1, MNH-812, MNH-806, MNH-636, FH-113, 4 F, MS-40, CIM-1100, 1021(Kivi), L.S.S, MNH-807, FH-682, 841/52 were the top 15 genotypes more tolerant and stable at drought stress condition.

Key words: Cotton, drought, selection index.