Genotype x environment interaction and associations among stability parameters in durum wheat (Triticum turgidum Var. Durum)

Abstract

Identification of stable and high yielding variety is one of the main objectives of any breeding program. However, genotype by environment interaction (GEI) affects performance of genotypes making it difficult for varietal recommendation. Therefore, this experiment was conducted with the objectives of assessing genotype by environment interaction (GEI), determining stable genotypes, and the associations among different stability parameters. The experiment was conducted at six locations in Amhara Region of Ethiopia during 2018/2019cropping season. Twelve durum wheat varieties were used using randomized complete block design with three replications. Combined analysis of variance (ANOVA) for grain yield was executed. The stability of the varieties were assessed using Ebrehart and Russel’ model, Wricks’ ecovalence (Wi), cultivar superiority measure (Pi), Nassar and Huehn’s mean absolute rank difference (Si1) and variance of ranks (Si2), Kang’s yield stability index (YSI), AMMI stability value (ASV), and AMMI models. The ANOVA showed highly significant difference among the genotypes, locations and their interactions. The study revealed that there was positive and significant associations among the stability parameters including bi, S2di, AMMI-1, ASV, Wi, Si(1), and Si(2), providing similar aspects of information in identifying durum wheat genotypes in the context of Amhara region of Ethiopia. Moreover, Pi and YSI were positively and significantly associated with grain yield indicating these models were best in identifying stable durum wheat varieties. Based on Pi stability measurement, Hitossa and Fetan were the most stable varieties, and can be recommended for the testing locations and similar agro-ecologies for large scale  production.