بررسي اثر متقابل سال و ژنوتيپ بر وراثت پذيري صفات و پيشرفت ژنتيكي ناشي از انتخاب در يك جامعه دابل هاپلوئيد گندم

An Investigation of Genotype by Year Interaction on Heritability and Genetic Gain from Selection in a Doubled Haploid Population of Wheat

In order to investigate the effect of year and interaction between year and genotype on variance components, heritability and genetic gain from selection for different traits in a doubled haploid wheat (Triticum aestivum L.) population, 157 lines developed from a cross between a wheat cultivar Fukuho-komugi and a breeding line of Oligoculm were evaluated in a randomized complete block design with three replications during growing seasons of 2003 and 2004. The results showed that phenotypic expression of grain yield, biological yield and spikes/m2 were more affected by year than by the other traits. Also, a higher estimation of genotype * year variance was found for these traits. High variation in estimation of the heritabilities and expected genetic gain in 2003 and 2004 and based upon the combined data of both years for grain yield, biological yield, 1000-grain weight and spikes/m2 indicated that there were considerable effects of year as well as of its interaction by genotype on these estimations. The estimated heritabilities (63%, 32% and 36%) and expected genetic gain based on the population mean (22.5%, 14.2% and 10.1%) in 2003 and 2004 and the combined data for grain yield showed that this economical trait can be improved through selection programs. An estimation of expected genetic gain in 2003 and 2004 and based upon a combined data of both years for grain yield were 2048, 754 and 727 kg/ha respectively. These results indicate that an evaluation of wheat genotypes in only one year may not provide adequate appropriate estimates of the heritabilities and genetic gains for yield, biological yield and spikes/m2 and the genotypes should be evaluated in a more than one year lapes of time.