ESTIMATION OF HETEROSIS AND COMBINING ABILITY FOR YIELDAND ITS COMPONENTS OF WHEAT

摘要

Six genotypes of wheat were carried out in the city of Ramadi Anbar province - Iraq. Genotypes were crossed in using half-diallel analysis during winter season (2016-2017) to produced fifteen Fl crosses. The parent and crosses were cultivated during the season (2017-2018) by RCBD with three replications to estimate heterosis, combining ability and gene action for yield and yield components. The results were showed that high significant were found between parents and Fl crosses. This study indicatinga wide genetic variability for the studied traits. Several crosses recorded significant positive heterosis percentages relative to better parent for seed yield per plant which ranged from -7.28 to 45.04. Both GCA and SCA were significant for all studiedtraits revealing the important role of both additive and dominance gene in the inheritance of the studied traits. Several crosses exhibited significantly positive SCA effects all studied traits especially (Alrashid x Buhutha22) which positive effects forseed yield per plant and 1000 seed weight. Heritability in narrow sense was high for plant height while it was low for grain yield per plant, as well as another trait such as spike length, number of spike/m2, number of grain/ spike and weight of 1000 grain was medium. This results indicated that some gertotypes could be use in breeding program to develop new hybrid with highest seed yield.