Multi-trait selection for mean performance and stability among soybean genotypes evaluated under rainfed conditions across diverse environments in India

Soybean [Glycine max (L.) Merr.] is the predominant rainfed Indian oilseed crop cultivated across diverse agro-climatic zones. Understanding the genotype ? environment interaction (GEI) is crucial for development of stable and wider adaptable soybean varieties. In the current study, 10 elite breeding lines were evaluated across 19 diverse locations for days to flowering, days to maturity, plant height, hundred seed weight and grain yield during 2020. The stability index as measured through weighted average of absolute scores (WAASB) identified SL 1213 and DS 1320 to have stable grain yield. WAASBY superiority index, which is based on mean performance and stability, was also higher for SL 1213. Multitrait stability index (MTSI) was employed to select genotypes with higher grain yield, early flowering, early maturity, higher hundred seed weight and plant height, simultaneously and genotypes DS 1320 and SL 1213 were identified through MTSI. Based on the three indices, SL 1213 was found to be the candidate genotype for breeding for higher yield, wider adaptability and for ideotype breeding. Based on cluster analysis, SL 1213 ? JS 22-07 and SL 1213 ? NRC 149 were found to be the ideal cross combinations for developing high-yielding and wider adaptable genotypes. Through Principal Component Analysis (PCA), grain yield was found to be positively associated with Relative Humidity, Effect of temperature on radiation use efficiency, Deficit by precipitation, Total rainfall precipitation during the crop cycle, Global solar radiation based on latitude and Julian day and Dew-point temperature at 2 m above the surface of the earth.