Environment X Genetic Stability of Different Sorghum Bicolor Varieties/Promising Lines Under Various Environmental Conditions

Abstract

Sorghum (Sorghum bicolor L. Moench) as an important food and fuel crop is undergone breeding for novel types, and its expansion into the new environments is necessary, however the efforts become complicated for breeders as well as agronomists to select for the best performing genotype in a particular environment due to unexpected, but significant genotype x environment interaction. This study was performed to thoroughly analyse the trade-offs between the agronomic performance and stability of sorghum genotypes produced under agro ecological conditions of Bahawalpur, Pakistan. Three sorghum lines i.e., G1 (S14), G2 (S22) and G3 (Jowar-86) were evaluated under eight environments which were formed by combining two sites of varying soil conditions (saline and normal soil) and were sown at four different sowing dates in order to determine the yield performance. Furthermore, AMMI analysis and GGE (generation×gene×environment) interactions were performed to identify the most stable variety for semi-arid environment. The results revealed that soil conditions significantly affect the grain yield of sorghum. The highest yield was obtained in E4 (1799 kg ha -1) under normal soil conditions and the best performing line was identified as G1. While under saline/problematic conditions E3 gave mean yield of 1530 kg ha-1 while line G1 gave 1505 kg ha-1 of yield. As far as the AMMI and GGE analysis is concerned, significant value for scores of PCAs were obtained as PC1 (61.3%) and PC2 (38.7%) while GGE analysis also gave significantly different scores for PC1 and PC2 as 86.8 and 13.2% respectively. The genotype G1 had low PC1 scores (1.59) as compared to G2 and G3 and thus it was identified as most stable genotype. The environment (E3) and (E4) were highly correlated to each and (E6), (E8) were discriminatory environments for all tested genotypes.