Organization of Genetic Variability and Trait-specific Accessions in a Diverse Set of Horse Gram [Macrotyloma uniflorum (Lam.) Verdc.] Germplasm

Abstract

Background: Mere presence of phenotype-based quantitative traits (QT’s) variability is of less significance in breeding crops including horse gram. A dependable knowledge on relative contribution of genetic and non-genetic sources on the QT’s variability and organization of variability in terms of similar and diverse groups of genotypes is useful in selection of most desired parents to generate breeding populations and in formulating appropriate selection strategies to breed improved horse gram cultivars. The objectives of the study were to (i) quantify QT’s variability and (ii) identify trait-specific accessions in a diverse set of germplasm accessions. Methods: A set of 196 horse gram germplasm accessions along with two checks were evaluated in simple lattice design with two replications at two locations, representing southern and eastern dry zones of Karnataka, India during 2020 and 2021 late rainy seasons for five quantitative traits. Result: The germplasm accessions differed significantly and variance attributable to genotypes contributed over 95% to total phenotypic variance for all the traits. The germplasm accessions could be grouped into four clusters. The quantitative trait means and variances of accessions distributed among the four clusters differed significantly. The trait-specific accessions identified in our study are suggested for preferential use in generating variability followed by selection in F2/BC1 populations for economically important traits.