گزينش همزمان براي عملكرد و پايداري و مقايسه آن با آمارهاي مختلف پايداري

Simultaneous Selection for Yield and Yield Stability and its Comparison with Different Stability Statistics

Both yield and stability of yield should be considered simultaneously in order to reduce effect of genotype * environment interaction and to make selection of genotypes more precise and effective. One applied method is simultaneous selection for yield and stability (YS;). The objective of this study was to utilize YS; statistic in cultivar selection and compare the results with other statistics such as S^2i , CV;, S^2di, and R^2i, Twelve foreign corn hybrids with two Iranian check hybrids, SC 704 and SC 604, were evaluated in a randomized complete-block design with four replications at five locations in 1996 cropping season. Six hybrids with overall mean grain yield of 11.31 tha^-1 were selected by Kangʹs method. Overall mean yield of selected hybrids by only yield (regardless of hybrid stability), yield plus environmental variance (or environmental coefficient of variation) and yield plus coefficient of regression and deviations from regression mean squares were 11.30, 11.16 and 11.31 tha^-1, respectively. Regard to the LSD%5 (-0/827), differences among overall mean yields or different selection creteria (different stability statistics) were not significant. It is concluded that when we use YS[ statistic, we can insure precise selection of the clutivar.