ESTIMATION OF GENETIC PARAMETERS FOR YIELD AND YIELD COMPONENTS IN SUNFLOWER UNDER NORMAL AND STRESS WATER DEFICIT

M. R Shakiba, M. Toorchi, S. S Alavikia, A. Pourmohammad

Abstract: The description of a suitable breeding strategy in drought prone environments is an important function for sunflower breeders. To achieve this function, dependable information on heritability and gene effects on yield and related traits under these conditions is necessary. Thirty sunflower hybrids were produced by line × tester cross of six male-sterile and five restorer lines. hybrids were evaluated in three levels of irrigation as follows: non-stressed plots irrigated at regular intervals (W1), mild water stress (W2), from the beginning of button stage (R4) to seed filling initiation (R6), and severe water stress (W3) started from the beginning of button stage (R4) to physiological maturity. Based on observations, plant height, stem diameter, number of seed were controlled by additive effects under irrigation conditions. Head diameter, plant height, stem diameter, 1000-seed weight, number of seed and yield were controlled by additive effects under mild stressed conditions. Under severe stress conditions, however, head diameter, plant height, stem diameter, number of seeds were controlled by additive effects, plant height and stem diameter were controlled by both additive and dominant effects and Seed yield was mainly influenced by dominant effects. Yield correlated positively with head diameter and plant height, 1000-seed weight and number of seeds. According to heritability and correlation between traits, under drought stressed conditions in breeding programs, number of seed, head diameter and plant height can be reliable criteria for selection of tolerant genotypes with higher yields.

Keywords: drought stress; gene action; heritability; line tester; sunflower

Date published: 2017-08-29