TY - JOUR T1 - Estimation of Genetic Parameters for Grain Yield and Related Traits in Wheat Using Diallel Analysis Under Optimum and Moisture Stress Conditions TT - برآورد پارامترهای ژنتیکی عملکرد دانه گندم و خصوصیات مرتبط با آن به روش تلاقی دای‌آلل در شرایط رطوبتی مطلوب و تنش خشکی JF - JSTNAR JO - JSTNAR VL - 11 IS - 1 UR - http://jstnar.iut.ac.ir/article-1-659-en.html Y1 - 2007 SP - 229 EP - 241 KW - Wheat KW - Diallel cross KW - Combining ability KW - Gene effect KW - Environmerrtal effect. N2 - Half diallel crosses of eight bread wheat cultivars were used to estimate the genetic parameters and types of genetic control for yield and yield components, and to determine the effects of environmental factors on these parameters. Parents and their F2 hybrids were grown in a randomized block design under irrigated and stressed (terminal drought) conditions. For all traits, except for number of spikelets per spike and number of grain per spike, the effect of environment (irrigated v.s stressed) and genotype by environment interaction were significant. The mean square of GCA for all characters was significant in both environments, except for number of fertile tillers in the irrigated condition and grain yield in the stressed conditions. The mean square of SCA was significant for plant height only in the irrigated condition, while for number of fertile tillers and grain yield it was significant in both conditions. The high significant ratios of GCA to SCA mean square indicated the importance of additive genetic effects on controlling plant height, spike length number of grain per spike in both environments and number of spikelets per spike in the stressed condition. The parameter estimation revealed partial dominance gene actions for plant height, spike length and grain per spike in both environments, and number of spikelets per spike in stressed environment, whereas over-dominance gene actions were observed for the other traits in one or both conditions. M3 ER -