Location: Crop Protection and Management ResearchTitle: Construction of a Genetic Linkage Map and Identification of QTLs for Resistance to TSWV in Cultivated Peanut (Arachis hypagea L.) Author
Submitted to: American Peanut Research and Education Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 7/1/2010
Publication Date: 7/10/2010
Citation: Qin, H. Guo, B. Li, Y. Culbreath, A. Guo, Y. Knapp, S. He, G. Chen, C.Y. Cook, D. Holbrook, C.C. Wang, M.L. Tillman, B. Isleib, T. 2010. Construction of a Genetic Linkage Map and Identification of QTLs for Resistance to TSWV in Cultivated Peanut (Arachis hypagea L.)[abstract]. Presented at the APRES annual meeting in Clearwater, FL. on July 13-17, 2010. Interpretive Summary:
Technical Abstract: A genetic linkage map is critical for identifying the QTL (quantitative trait loci) underling targeted traits. Over the last few years, progress has been made in marker development from multiple sources enabling the expansion of quality resources needed for genotyping applications in cultivated x cultivated populations. The most recently published intra-specific maps were constructed from the crosses of cultivated peanuts (Varshney et al. 2009; Hong et al. 2010), in which only 135 and 175 simple sequence repeat (SSR) markers were sparsely populated in 22 linkage groups, respectively, representing the 20 chromosomes of A. hypogaea. A high resolution linkage map with sufficient markers will increase the chances of QTL identification. Two intra-specific F2:7-RIL (recombinant inbred line) populations of 248 and 352 lines derived by single seed descent from crosses between ‘Tifrunner’ × GT-C20 and ‘SunOleic 97R’ × NC94022’ have been developed and used in this study. The primary phenotype evaluation conducted in 2009 (F2:5) has demonstrated that a significant divergence among RILs of both populations was obvious. The populations are suitable for linkage map construction and QTL analysis. We have collected 4,574 SSR markers and screened for polymorphisms in the parents. Of these SSRs, 269 and 173 markers were polymorphic in these two populations, respectively, and used for the genetic map constructions. The constructed linkage genetic map for S population has 20 linkage groups (LG) with 186 mapped loci (173 SSRs and 13 with two loci). In 2009, we conducted field evaluation of F2:5 lines for disease resistance to TSWV with two replications. From our preliminary result, one QTL for TSWV resistance has been identified. The identified QTL may explain 40% phenotypic variation. The seeds for these populations have been advanced to next generation (F2:7) and more field phenotypes will be conducted in 2010 for confirming this major QTL. This map will be compared with the genetic map from T population. Furthermore, an integrated map will be constructed from these two populations with more markers to better cover the peanut genome.