WAASB-based stability analysis and simultaneous selection of forage sorghum for forage yield traits

Abstract

In response to the growing population and increasing demand for cattle products, enhancing sorghum forage yield is essential for ensuring food security. This study aimed to identify stable genotypes with high forage yields and key yield traits for sorghum breeding programs. Ninety-five forage sorghum lines were evaluated under five distinct climatic conditions over two years (2020–2021), revealing significant genotype × environment interaction (GEI) effects for 14 agronomic traits. Two BLUP-based mixed model stability methods, weight average absolute score based on BLUP (WAASB) and the multi-trait stability index (MTSI), were employed for stability analysis. Three genotypes, G90 (424B), G80 (382B) and G3 (349B) were identified stable and high yielding for forage yield based on WAASB based methods. The MTSI, a novel simultaneous selection index, effectively selected genotypes based on multiple agro-morphological traits, except for the leaf-to-stem ratio. Genotypes G81, G90, G80, and G89 were identified as desirable based on the MTSI. The strength and weakness plot is highlighted as a valuable graphical tool for identifying and selecting genotypes based on trait strengths and weaknesses. Among these, G90 (424B) and G80 (382B) stood out as superior, excelling in both forage yield and early maturity, as determined by WAASB based methods and MTSI method. These genotypes warrant further comprehensive investigation across diverse environments and show significant potential for future breeding programs.