QTL analysis of seed size and yield-related traits in an inter-genepool population of common bean (Phaseolus vulgaris L.)

Abstract

Quantitative trait locus (QTL) analysis of seed size and yield-related traits provide useful information to contribute to breeding programs. A recombinant inbred line population composed of 100 lines from a cross of Goli cultivar and breeding line AND1007 was grown in field and greenhouse conditions to identify QTLs controlling the important primary traits affecting seed size and yield-related traits. A linkage map consisting of 240 SNPs, spanning ∼520 cM of common bean genome was used for QTL mapping. A total of 39 QTLs were identified on different chromosomes, which explained 5 to 32–32 % of the phenotypic variance for the measured traits. Thirty-one of them had only individual effects, six were only involved in three epistatic interactions and two had both individual and epistatic effects. Most of the positive alleles for seed size traits and number of seeds per pod originated from the Andean parent (AND1007) while the alleles related to number of pod and seeds per plant originated from Mesoamerican parent (Goli). QTLs for seed weight, seed length and seed yield co-localized on the Pv09, suggesting these traits may be controlled by QTLs that are linked together or have pleiotropic effects. A major QTL was found for seed length (SL9.1GA) which explained ∼32 % of the phenotypic variance and had repeatability over field and greenhouse trials. Overall, results showed that QTLs with single-locus additive and epistatic effects were involved in the control of bean seed size and yield-related traits while the effects of epistatic interactions were smaller than single-locus QTLs.