GENETIC AND GENOMIC APPROACHES TO IMPROVE PEANUT AND CORN RESISTANCE TO DISEASE AND AFLATOXIN CONTAMINATION
Location: Crop Protection and Management Research
Title: Identification of molecular markers associated with resistance to TSWV and leaf spots through genetic mapping and selction of high oleic cultivars with high resistance to TSWV
Submitted to: American Peanut Council Meeting
Publication Type: Abstract Only
Publication Acceptance Date: March 7, 2011
Publication Date: March 7, 2011
Citation: Guo, B., Culbreath, A., Brenneman, T., Chen, C.Y., Holbrook Jr, C.C., Wang, M.L. 2011. Identification of molecular markers associated with resistance to TSWV and leaf spots through genetic mapping and selction of high oleic cultivars with high resistance to TSWV [abstract]. American Peanut Council Meeting. March 7-9, 2011. Washington, D.C.
Peanut is vulnerable to a range of diseases, such as tomato spotted wilt virus (TSWV), early (Cercospora arachidicola) and late (Cercosporidium personatum) leaf spots, and southern stem rot/white mold (Sclerotium rolfsii). In peanut production areas in the southeastern U.S., tomato spotted wilt virus disease caused by tomato spotted wilt tospovirus (TSWV) has become more prevalent and more severe. White mold also is a common and often destructive disease of peanut. Nevertheless, the application of biotechnology for improving the cultivated peanut has been hampered by an inability to visualize sufficient genetic variation and by lack of a high-resolution linkage map. Therefore, the objective of this study was to develop a comparative integrated genetic linkage map for cultivated peanut from two RIL populations with diverse genetic backgrounds, in which two runner type cultivars (Tifrunner and SunOleic 97R), one Spanish type cultivar (GT-C20) and one breeding line derived from a cross of Virginia type and hirsuta type (NC94022) were used as parents.
Construction and improvement of a genetic map for peanut (Arachis hypogaea L.) 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 integrated map from two recombinant inbred line (RIL) populations with diverse backgrounds in which two runner type cultivars, one Spanish type cultivar and one breeding line derived from a cross of Virginia type and hirsuta type were used as parents. A total of 4576 simple sequence repeat (SSR) markers from three sources: published SSR markers, newly developed SSR markers from expressed sequence tags (EST) and from bacterial artificial chromosome (BAC) end-sequences were 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 linkage groups (LGs). Combining information from duplicated loci between LGs and comparing with published diploid maps, 7 homoeologous groups were defined and 17 LGs (A1 to A10, B1 to B4, B7, B8, and B9) were aligned to corresponding A-subgenome or B-subgenome of diploid progenitors. LGs for the A-subgenome covered 796.0 cM with 200 loci, and for the B subgenome covered 556.1 cM with 123 loci. One reciprocal translocation was confirmed in the tetraploid cultivated peanut genome. Several chromosomal rearrangements were observed by comparing to published cultivated peanut maps. There were 42, 30 and 46 collinear markers between this integrated map and three published cultivated linkage maps, respectively.
Using this developed map, we have detected two QTLs for resistance to TSWV in these two populations, and 2010 field data have been collected for detection of QTLs associated with resistance to early and late leaf spots. The total oil and oleic contents have been analyzed and