Comparative Efficiency of GY*T Approach Over GT Approach in Genotypic Selection in Multiple Trait Evaluations: Case Study of Common Bean (Phaseolus vulgaris) Grown Under Temperate Himalayan Conditions

Abstract

The subjectivity of index selection and unpredictable environmental variabilities cause ambiguities in multiple-trait selection across environments. In the present study, we tested and validated a recently proposed multivariate approach for genotypic selection based on multiple trait evaluations. A genotype by yield*trait (GY*T) biplot approach originally proposed was validated in this study to assess the comparative efficiency of GY*T approach over genotype by trait (GT) approach in genotypic selection on multiple traits in common bean. The analysis is based on six trials spread over four years from 2015–2018 at two locations. Based on the GY*T analysis, the biplot could improve the variation accounted for by PCI and PC2 from 71.37 to 92.81%. The genotypes WB-341, WB-1634 and WB-451 were identified as high yielding and possessed higher seed yield on account of higher values of pods per plant and seeds per pod indicating that these possess the ideal trait combination of yield, pod number and seeds per pod. The genotype WB-222 had the ideal trait combination of yield, pods per plant and plant height. Similarly the genotype WB-185 had the ideal trait combination of yield and 100-seed weight but was poor for pods per plant. The genotype WB-83 had an opposite trait profile to WB-185 especially for 100-seed weight, but was good for pods per plant, even though both had comparable yield levels. Based on the results of present study and few earlier studies, we conclude that GY*T approach based on multi-trait data is comparatively more efficient than GT biplot.