Estimation of heritability and some genetic parameters for yield and yield-related traits of wheat using Diallel design

Wheat is one of the most important edible crops used in several food products. The success of plant breeding programs depends on the availability of parents with desired genetic diversities. In this context, we evaluated the genetic parameters in eight wheat genotypes namely Kohdashet, Morvaread, N-80-19, Darya, UR-82-17, Ehsan, Bacounoura and Atrack as well as theirs F1 progenies in term of grain yield and the relevant traits. Randomized complete block design with three replications was used. Data analysis indicated that genotypes and their F1 hybrids significantly affected grain yield, biological yield, thousand-grain weight, grains per spike, grain weight in spike, plant height, peduncle length and second internode length. The Model I of Griffing's method II was used in SAS software to determine GCA, SCA and other genetic parameters. Among parents, Ehsan cultivar exhibited the highest GCA for grain yield, thousand-grain weight, grain weight in spike, plant height and biological yield. P6×P7 cross was found to have the highest SCA effects on grain yield, thousand-grain weight and plant height. In addition, among examined characteristics, the thousand-grain weight and the peduncle length had the highest broad sense (h2= 0.98) and narrow sense heritability (H2= 0.62), respectively. These findings indicated that the distinctive crosses engaged in progenitors belongs to high×low GCA; therefore, it is inessential to set crosses with high×high GCA. As a result, potential homozygous lines can be selected from transgressive segregations to increase yield. Such crosses can be applied for exploiting heterosis.