Performance stability for grain yield and genotypes by environment interaction in field pea genotypes in the highlands of Bale Southeastern Ethiopia

Thirteen field pea genotypes were evaluated along with two standard checks, Harena and Tullushenen, and local cultivar for three consecutive years ۲۰۱۶ to ۲۰۱۸ main cropping season, bona, in the highlands of Bale, Southeastern Ethiopia. The study was conducted using randomized complete block design with four replication in order to identify high yielding, stable field pea genotypes with resistance or tolerant types of reaction for major diseases in the study areas. Genotypes X environment interaction and grain yield stability were analyzed and estimated using AMMI model analysis. The AMMI model analysis revealed significant variation for genotypes, environment, genotype x environment interaction at (P<۰.۰۱%.). The environment accounted for ۸۲.۹۹% of the total variation for yield whereas the genotypes accounted for ۹.۵۴% and the Genotypes x environment interaction explained for ۷.۴۶% of the total variation for grain yield. This indicates that the tested genotypes responded differently to the environment or the environment differently discriminate the genotypes. The first two AMMI components also showed significant variation and totally accounted for ۵۵.۴۵% which indicates at the model fit for this study. Based on the stability parameters like ASV and GSI used to discriminate the stable genotypes, G۱۴, G۸ G۴, G۱۶ and G۳ had lower ASV and showed stable performance over the testing environments. In order to reduce the effect of GE interaction and to make selection of genotypes more precise and refined, both yield and stability of performance should be considered simultaneously. Accordingly, genotypes with code, G۵, G۴ and G۱۴ had lower GSI indicating stable performance. But G۵ had almost equal mean grain yield with the check (G۱۴). Furthermore, this genotype besides its stable performance over the tested environment, it showed tolerant types of reaction for Powdery mildew, Downey mildew and Aschochtya blight. Therefore, G۴, (ACC۳۲۰۰۳-۲) was identified as candidate genotypes to be verified in the coming cropping season for possible release for the highlands of Bale and similar agro-ecologies.Thirteen field pea genotypes were evaluated along with two standard checks, Harena and Tullushenen, and local cultivar for three consecutive years ۲۰۱۶ to ۲۰۱۸ main cropping season, bona, in the highlands of Bale, Southeastern Ethiopia. The study was conducted using randomized complete block design with four replication in order to identify high yielding, stable field pea genotypes with resistance or tolerant types of reaction for major diseases in the study areas. Genotypes X environment interaction and grain yield stability were analyzed and estimated using AMMI model analysis. The AMMI model analysis revealed significant variation for genotypes, environment, genotype x environment interaction at (P<۰.۰۱%.). The environment accounted for ۸۲.۹۹% of the total variation for yield whereas the genotypes accounted for ۹.۵۴% and the Genotypes x environment interaction explained for ۷.۴۶% of the total variation for grain yield. This indicates that the tested genotypes responded differently to the environment or the environment differently discriminate the genotypes. The first two AMMI components also showed significant variation and totally accounted for ۵۵.۴۵% which indicates at the model fit for this study. Based on the stability parameters like ASV and GSI used to discriminate the stable genotypes, G۱۴, G۸ G۴, G۱۶ and G۳ had lower ASV and showed stable performance over the testing environments. In order to reduce the effect of GE interaction and to make selection of genotypes more precise and refined, both yield and stability of performance should be considered simultaneously. Accordingly, genotypes with code, G۵, G۴ and G۱۴ had lower GSI indicating stable performance. But G۵ had almost equal mean grain yield with the check (G۱۴). Furthermore, this genotype besides its stable performance over the tested environment, it showed tolerant types of reaction for Powdery mildew, Downey mildew and Aschochtya blight. Therefore, G۴, (ACC۳۲۰۰۳-۲) was identified as candidate genotypes to be verified in the coming cropping season for possible release for the highlands of Bale and similar agro-ecologies.

Keywords:

AMMI , AMMI Stability Value (ASV) , Genotypes Selection Index (GSI) , Grain yield , Stability