A. POURMOHAMMAD1, M. TOORCHI1, S. S ALAVIKIA1 and M. R SHAKIBA2
1 University of Tabriz, Department of Plant breeding and Biotechnology, Faculty of Agriculture, Tabriz 51664, Iran
2 University of Tabriz, Department of Plant Eco-physiology, Faculty of Agriculture, Tabriz 51664, Iran
POURMOHAMMAD, A., M. TOORCHI, S. S ALAVIKIA and M. R SHAKIBA, 2016. Estimation of genetic parameters for yield and yield components in sunfl ower under normal and stress water defi cit. Bulg. J. Agric. Sci., 22: 426–430
The description of a suitable breeding strategy in drought prone environments is an important function for sunfl ower breeders. To achieve this function, dependable information on heritability and gene effects on yield and related traits under these conditions is necessary. Thirty sunfl ower 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 fi lling 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 infl uenced 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.