Toward validation of QTLs associated with pod and seed size in common bean using two nested recombinant inbred line populations

Authors: MURUBE, ESTER - Agriculture Research And Development Service (SERIDA); CAMPA, ANA - Agriculture Research And Development Service (SERIDA); Song, Qijian; MCCLEAN, PHILLIP - North Dakota State University; FERREIRA, JUAN - Agriculture Research And Development Service (SERIDA)

Submitted to: Molecular Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/26/2019
Publication Date: 12/24/2019
Citation: Murube, E., Campa, A., Song, Q., Mcclean, P., Ferreira, J.J. 2019. Toward validation of QTLs associated with pod and seed size in common bean using two nested recombinant inbred line populations. Molecular Breeding. 40:7. https://doi.org/10.1007/s11032-019-1085-1.
DOI: https://doi.org/10.1007/s11032-019-1085-1

Interpretive Summary: Common bean is the most important legume crop for direct human consumption. Beans can be consumed as pods (green or snap beans) or as dry seeds after re-hydration (dry beans). The study of the genes responsible for pod and seeds is important to farmers and consumers. Traditional mapping of genes controlling traits requires markers associated with genes. In order for them to be useful in breeding, such markers need to be tested across different varieties of beans. In this study, we identified and validated several gene regions associated with seed and pod phenotypes in two beans with a common parent. The results reveal the complexity of the genetics for pod and seed formation. These findings will assist breeders in the government, at universities, and at private industry improve the development of high quality vegetable common bean cultivars.

Technical Abstract: Common bean (Phaseolus vulgaris L.) is an important legume worldwide which, depending on genotype, can be consumed as green pods or dry seeds after re-hydrated. The aim of this study was to identify QTL associated with seed and pod phenotype and evaluate the consistency of these QTL across different environments, studies and genetic backgrounds. Two nested recombinant inbred populations obtained from the crosses Xana/Cornell 4924 (XC) and Xana/ BAT93 (XB) were used. Populations were phenotyped for pod and seed size (length, width, thickness, area or perimeter), n. seed per pod and seed weigh in two (XB) or five seasons (XC) using a randomize complete-block design. XC population (115 lines) was re- genotyped using the BARCBean6K_3 bean chip and an updated linkage map with 732 makers and 1390 cM was developed. XB population (145 lines) was genotyped through genotyping by sequencing and the corresponding genetic maps consisted of 497 SNP with a total length of 1547 cM. Altogether, 13 and 18 QTL for pod traits and, 21 and 25 QTL for seed traits were detected in the XC and XB population, respectively. In addition, 20 and 27 significant epistatic interactions between QTL were detected in XC and XB populations, respectively. Overlap among identified QTL in two nested population were investigated considering the physical position of the underlying markers in the bean genome. Results revealed four overlapping regions for pod traits and eight for seed traits between XC and XB populations. QTL detected on telomeric genomic regions of the chromosomes Pv01, Pv05, Pv06, Pv07, Pv08 and Pv11 overlap with QTL reported previous works, also associated pod or seed phenotype. Results show the complex architecture of the genetic control of pod and seed phenotype and, the useful of the genome in the integration and validation of QTL.