|HAGERTY, C - Oregon State University|
|CUESTA-MARCOS, A - Oregon State University|
|CREGAN, P - Retired ARS Employee|
|MCCLEAN, P - North Dakota State University|
|MYERS, J - Oregon State University|
Submitted to: Journal of the American Society for Horticultural Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/23/2015
Publication Date: 3/1/2016
Citation: Hagerty, C.H., Cuesta-Marcos, A., Cregan, P., Song, Q., Mcclean, P., Myers, J.R. 2016. Mapping snap bean (Phaseolus vulgaris L.) pod and color traits, in a dry bean x snap bean recombinant inbred population. Journal of the American Society for Horticultural Science. 141(2):131-138.
Interpretive Summary: Snap beans are the vegetable form of common bean and harvested before seeds mature. Whole pods are prepared by cooking, or preserved by freezing or canning. The most important traits in snap beans are pod wall fiber content, pod thickness and pod well succulence and seed color. However, the genome map position of the genes controlling these traits in the common bean genome is unknown. In this study, we created progenies by crossing a dry bean with a snap bean accession and evaluated these progeny for processing and morphological traits. In addition, we assayed the progeny with the BARCBean6K_3 Beadchip containing 6,000 Single Nucleotide Polymorphism (SNP) markers. We identified the genomics regions of the genes controlling these traits and the extent of the genes affecting the traits. The finding in this research will assist breeders in understanding the effect of genetic factors controlling the traits and developing high quality vegetable common bean cultivars.
Technical Abstract: Snap bean (Phaseolus vulgaris) breeding programs are tasked with developing varieties that meet the standards of the vegetable processing industry and ultimately that of the consumer; all the while matching or exceeding the field performance of existing varieties. While traditional breeding methods have had a long history of meeting these requirements, genetic marker technology, combined with the knowledge of important quantitative trait loci (QTL), can accelerate breeding efforts. In contrast to dry beans, snap bean immature pods and seeds are consumed as a vegetable. Several pod traits are important in snap beans including: reduced pod wall fiber, absence of pod suture strings, and thickened, succulent pod walls. In addition, snap bean pods are selected for round pod cross-section, and pods tend to be longer with cylindrical seed shape. Seed color is an important trait in snap beans, especially those used for processing, as processors prefer white-seeded cultivars. The objective of this study was to investigate the genetic control of traits important to snap bean producers and processors. RR6950, a small seeded brown indeterminate type IIIA dry bean accession, was crossed to OSU 5446, a type I Blue Lake four-sieve breeding line to produce the RR138 F4:6 recombinant inbred mapping population. We evaluated the RR138 RI population for processing and morphological traits, especially those affecting pods. The RR138 population was genotyped on the Illumina BARCBean6K_3 Beadchip. The Single Nucleotide Polymorphism (SNP) data was used to assemble a linkage map, and identify QTL for pod traits. The linkage map produced from this study contained 1,689 SNPs across 1,196cM. The map was populated with an average of one SNP for every 1.4cM, spanning 11 linkage groups. In this study, seed and flower color genes B and P were located on Pv02 and Pv07, respectively. The location for P in our map based on SNP physical location was compared to the physical location of the putative candidate gene for P. We found locations did not coincide, which may be a function of P being located in a low recombinant region of the chromosome. A QTL for string:pod length ratio was found on Pv02 controlling 32% of total genetic variation. QTL for a suite of important processing traits including pod wall fiber, pod height, pod width, pod wall thickness, and pod wall thickness were found clustering on Pv07 and controlled 21, 26, 18, and 16% of genetic variation for each of these respective traits. A QTL for pod length was found on Pv09 controlling 5% of genetic variation.