Heritability and Genetic Relationships for Drought‐Related Traits in Peanut

Abstract

ABSTRACTWater‐use efficiency is often genetically correlated with specific leaf area (SLA) and leaf C isotopic composition (δ13C) in peanut (Arachis hypogaea L.). The objectives of this study were to examine the effects of environment, genotype, and genotype × environment interaction on SLA, δ13C, harvest index (HI), and yield and to estimate heritability and the genetic relationships. Fifteen genotypes were tested at two locations with different drought intensities for 2 yr. The additive main effects and multiplicative interaction analysis based on yield data divided eight environments (locations × treatments × years) into four clusters, which reflected a gradient in drought stress, indicating yield trait is a good indication of drought stress. The genotype Exp8‐12 was identified as a best drought tolerant germplasm across environments. Heritability estimates for HI (0.68 to 0.89) and δ13C (0.75 to 0.89) were higher than those for SLA (0.31 to 0.88) and yield (0.12 to 0.65). A positive but small genetic correlation coefficient (rg) (0.26) was found between HI and yield, and low to moderate rg (0.14 to 0.55) were observed between HI and SLA. A relative high negative genetic correlation rg (−0.81 to −0.57) was found between δ13C and yield. In theory, the high heritability and no G×E interaction for δ13C make it possible a surrogate that can be used to assess drought tolerance in peanut breeding.