In the developing world, plant breeding and seed improvement systems must be promoted to reduce the crops vulnerability. Development of improved genotypes of different crop plants through enlightened plant breeding are earnestly needed to deliver climate change adaptation and help in food security. Five durum wheat cultivars (Syrian-4, Dumes-1, Sham-7, Yousef-1 and Haurani) were crossed during 2016-17 in a half diallel fashion to create 10 F-1 hybrids at Duhok University, Iraq. During 2017-18, the seeds of all the genotypes (five parental genotypes + 10 F-1 hybrids) were grown with early (November 20, 2017) and late (December 20, 2017) sowing in a randomized complete block design (RCBD) with three replications at two different locations i.e., Sumel - Duhok University and Amedi - Duhok city, Iraq. The combined analysis of variance showed significant (p <= 0.01) differences for hybrids, environments, and hybrid x environment interactions. Analysis of variance for combining ability showed that mean squares due to GCA and SCA were significant (p <= 0.01) indicating the role of both additive and non-additive gene effects in inheritance of studied traits. In general, parental lines i.e., Sham-7 and Haurani were found as good general combiners for most of characters. The SCA effects were significant for three hybrids i.e., Syrian-4 x Sham-7, Sham-7 x Haurani and Duma-1 x Haurani for majority of the characters. In order to determine the stability of genotypes in four different environments, the stability parameters were used to identify the stable genotypes through regression coefficient (Bi) and variance of deviation from regression (S(2)d). Results further revealed that genotypes differed in their response across various environments for all the variables. Some genotypes reflected stability for one character and unstable for other trait, showing a wide range of variation. According to stability parameters parental lines (Sham-7 and Haurani) and F-1 hybrids i.e., Duma-1 x Haurani, Sham-7 x Haurani and Duma-1 x Sham-7, had the best stability for grain yield and its components, thus indicating a wide range of adaptation across environments. These investigations will play an important role in managing some strategies for improvement in durum wheat through diallel cross in future breeding program.
Askander, HSA
COMBINING ABILITY AND STABILITY STUDIES IN F1 POPULATIONS OF TRITICUM DURUM ACROSS ENVIRONMENTS
Pakistan Journal Of Botany