Location: Crop Protection and Management Research
Title: Construction of a genetic linkage map for cultivated peanut and development of QTLs/markers for marker-assisted breeding Author
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 28, 2012
Publication Date: March 28, 2012
Citation: Guo, B. 2012. Construction of a genetic linkage map for cultivated peanut and development of QTLs/markers for marker-assisted breeding [abstract]. Peanut Foundation Annual Project Report Meeting. March 29, 2012. Atlanta, GA. Technical Abstract: Several genetic maps based on recombinant inbred line (RIL) and backcross (BC) populations have been developed for tetraploid peanut recently. The marker density, however, is still very low especially in context of large genome size (2,800Mb/1C) and 20 linkage groups (LGs). Therefore, improvement of peanut genetic linkage map continues to be an important task in order to facilitate quantitative trait locus (QTL) analysis and the development of tools for marker-assisted breeding. The objective of this study was to develop a comparative genetic linkage map from cultivated x cultivated segregation populations and to apply in mapping TSWV resistance and other important agronomic traits in peanut breeding. A total of 4576 simple sequence repeat (SSR) markers were collected and used for screening polymorphisms. Two CAPS (cleaved amplified polymorphic sequence) markers were also included to differentiate ahFAD2A alleles and ahFAD2B alleles. A total of 324 markers were anchored on this integrated map covering 1,352.1 cM with 21 LGs; and 7 homoeologous groups were defined. Seventeen LGs (A1 to A10, B1 to B4, B7, B8, and B9) were aligned to corresponding A-subgenome or B-subgenome of diploid progenitors. Further two major QTLs for TSWV resistance were identified. By using the published peanut maps and the marker segregation data from 10 RILs and one BC population collectively, a reference consensus genetic map has been developed. This map is comprised of 913 marker loci including 911 SSRs and 2 CAPS loci distributed on 20 LGs spanning a map distance of 3,607.97 cM. This reference consensus map will serve as a reliable reference for aligning new genetic and physical maps, performing QTL analysis in a multiple-population design, and evaluating the genetic background effect on QTL expression. In 2011 field trial/phenotyping, there were three planting date and each with 3 replications for both populations ((156 + 354) x 3 x 3) = 4590). PCR-based gene-specific markers have been developed for two putative TSWV resistance genes.