Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 4/18/2008
Publication Date: 7/15/2008
Citation: Chen, X.; Culbreath, A.; Brenneman, T.; Holbrook Jr., C.; Guo, B. 2008. Identification and cloning of TSWV resistance gene(s) in cultivated peanuts and development of markers for breeding selection [abstract]. Proceedings from the American Phytopathological Society Meeting, July 26-30, 2008, Minneapolis, MN.
Technical Abstract: Tomato spotted wilt virus, transmitted to plant via thrips, is a destructive pathogen with a worldwide distribution. TSWV has caused a very serious problem in peanut (Arachis hypogaea L.) producing areas in US. In past decades, different tactics (resistant cultivars, chemical, crop rotation and other field practices) have been employed to control spotted wilt. The most promising solution for managing spotted wilt is development of resistant cultivars. Resistance genes to TSWV have been found in tomato and pepper, named Sw-5 and Tsw, respectively. We have discovered 41 gene fragments originally from peanut expressed sequence tags (ESTs) with significant homology to two tomato BAC sequences (AY007366 and AY007367), which spanned 5 different resistance candidate sequences. Reverse northern-blots have identified eighteen clones with significant levels of expression. Out of these clones, we identified one, named Ahsw, with approximately 37% of amino acid identity to tomato Sw-a that has been further characterized. Southern blot indicated that there are at least 4 copies of Ahsw gene in the cultivated peanut genome. Three restriction enzymes, HindIII, EcoRI and RsaI were used to examine whether the restriction fragment length polymorphism exists in these entries, which are resistant or susceptible to TSWV, using Ahsw as a probe. The results showed that different number and length of restriction fragments were observed in different genotypes, suggesting its potential use as a marker. Two mapping populations have been developed. Northern blots revealed different expression patterns of Ahsw, but further experiments are needed to confirm an association of this gene with resistance to TSWV.