Multi-environment Evaluations Across Ecological Regions Reveal That the Kernel Oil Content of Cottonseed Is Equally Determined by Genotype and Environment

Cotton is the fifth-largest
oil crop in the world. A high kernel
oil content (KOC) and high stability are important cottonseed attributes
for food security. In this study, the phenotype of KOC and the genotype-by-environment
interaction factors were collectively dissected using 250 recombinant
inbred lines, their parental cultivars sGK156 and 901-001, and CCRI70
across multi-environments. ANOVA and correlation analysis showed that
both genotype and environment contributed significantly to KOC accumulation.
Analyses of additive main effect multiplicative interaction and genotype-by-environment
interaction biplot models presented the effects of genotype, environment,
and genotype by environment on KOC performance and the stability of
the experimental materials. Interaction network analysis revealed
that meteorological and geographical factors explained 38% of the
total KOC variance, with average daily rainfall contributing the largest
positive impact and cumulative rainfall having the largest negative
impact on KOC accumulation. This study provides insight into KOC accumulation
and could direct selection strategies for improved KOC and field management
of cottonseed in the future.