Prediction of biomass sorghum hybrids using environmental feature-enriched genomic combining ability models in tropical environments.

Abstract

Key message: Incorporating environmental features improved the predictive ability of genomic prediction models under multi-environment trials in tropical conditions. Gathering environmental and genomic information can benefit the breeding of sorghum hybrids by overcoming complications imposed by the genotype-by-environment interaction (GEI). In this study, we explored the value of combining environmental features (EFs) and genomic data to enhance predictions for biomass sorghum hybrid breeding, addressing GEI complexities. We also investigated if considering specific time windows for EFs improves the prediction. We used a historical dataset from a tropical biomass sorghum breeding program featuring 253 genotypes across 64 trials. Initially, a first-stage analysis was performed to obtain the adjusted means (EBLUEs) and scrutinize the impact of 29 EFs (geographic, climatic, and soil-related EFs) on GEI. Subsequently, in the second-stage analysis, we used data from 221 hybrids that had both parents genotyped to evaluate the predictive ability and assertiveness of 12 models with different effects. The most relevant EFs included soil organic carbon, insolation on a horizontal surface, longitude, temperature at dew point, and nitrogen content. Across three cross-validation scenarios (CV1, CV0, and CV00), the most effective model encompassed main combining ability effects, GEI, and G $\omega$ I (genotype-by-specific environmental effects interaction), utilizing an environmental kinship matrix ( $\Omega$ ) derived from mean EF values. Only in CV2, a model with a similar structure but utilizing $\Omega$ from specific time windows outperformed others. Our findings highlight the potential of integrating environmental and genomic data to refine predictive models for optimizing biomass sorghum hybrid breeding strategies.