Location: Crop Protection and Management ResearchTitle: Saturation of genetic maps for identification of QTLs controlling biotic resistance, morphological descriptors and oil quality in tetraploid peanut Author
Submitted to: American Peanut Research and Education Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 5/15/2012
Publication Date: 7/10/2013
Citation: Pandey, M., Feng, S., Culbreath, A., Varshney, R., Wang, M.L., Barkley, N.L., Holbrook Jr, C.C., Guo, B. 2013. Saturation of genetic maps for identification of QTLs controlling biotic resistance, morphological descriptors and oil quality in tetraploid peanut [abstract]. American Peanut Research and Education Society Abstracts. Interpretive Summary:
Technical Abstract: Low genetic diversity in cultivated peanut severely hampered construction of high density genetic maps and as a result genetic maps constructed so far could not go beyond 200 markers. The marker density of these maps is not satisfactory concerning the large genome size, allotetraploid nature and 20 linkage groups. Biotic diseases such as tomato spotted wilt virus (TSWV) and late leaf spot (LLS) are constantly posing threat to sustainable peanut productivity of newly released cultivars. In addition, increased awareness among consumers towards health benefits demands for cultivars with good oil quality. In order to overcome the above constraints, two genetic maps were constructed using Tifrunner × GT-C20 (T population, 158 RILs) and SunOleic 97R × NC94022 (S population, 190 RILs) with 239 and 172 marker loci, respectively (Qin et al. 2012. TAG). Further, screening of markers resulted in the identification of an additional 69 polymorphic markers for the S-population. Realizing the potential of this population, phenotypic data were generated on several traits along with new genotypic data for 250 marker loci on 353 RIL lines. Using QTL Cartographer v 2.5, single marker analysis (SMA) with genotypic and phenotypic data resulted in the identification of highly significant (0.01%) markers for LLS (41 markers), TSWV (10 markers), flowering on the main axis (7 markers), growth habit (13 markers), visual prominence of the main stem (one marker), oleic acid (25 markers), linoleic acid (23 markers), oleic/linoleic (O/L) ratio (15 markers), palmitic acid (5 markers), stearic acid (7 markers), arachidic acid (11 markers), gadolic acid (4 markers), behenic acid (26 markers), lignoceric (21 markers) and cerotic (3 markers) acids. However, there were no significant markers detected for leaf color, total oil content and stem pigmentation. More significantly, a total of 13 common markers were detected in both seasons (2010 and 2011) for LLS resistance. Common markers were also detected between several other traits such as flowering on the main axis and growth habit (5), oleic, linoleic acids and O/L ratio (12), oleic and arachidic acids (7), behenic, oleic and linoleic acids (15), lignoceric, oleic and linoleic acids (11). A gene specific marker for the FAD2B gene was found to be significantly associated with all the fatty acid component traits except stearic, gadoleic and cerotic acids. The construction of a saturated genetic map and detailed QTL analysis is in progress and will be presented.