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Identification of Molecular Markers Associated with Root‐Knot Nematode Resistance in Upland Cotton
Author(s) -
Niu Chen,
Hinchliffe Doug J.,
Cantrell Roy G.,
Wang Congli,
Roberts Philip A.,
Zhang Jinfa
Publication year - 2007
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci2006.07.0499
Subject(s) - rapd , biology , germplasm , genetic marker , amplified fragment length polymorphism , genetics , molecular marker , marker assisted selection , meloidogyne incognita , population , root knot nematode , quantitative trait locus , gene , botany , nematode , genetic diversity , ecology , demography , sociology
Cotton breeding for resistance to root‐knot nematode (RKN) [ Meloidogyne incognita (Kofoid and White) Chitwood] is hindered by the lack of convenient and reliable screening methods for resistant plants. The identification of molecular markers closely linked to RKN resistance will facilitate the development of RKN resistant cultivars through marker‐assisted selection (MAS). Our objective was to identify and develop new DNA markers that are associated with RKN resistance in cotton. Using three pairs of near‐isogenic (NIL) resistant (R) and susceptible (S) lines, two AFLP markers, two RAPD markers, and three RGA markers were identified to be polymorphic between the NIL‐R and NIL‐S lines. One RAPD marker was converted into a sequence‐tagged site (STS) marker. In an F 2 population of ‘ST 474’ × ‘Auburn 634 RNR’, the two RAPD markers and the STS marker were mapped to the same linkage group containing several markers that were previously reported to be linked with the RKN resistance gene rkn1 on chromosome 11 in ‘Acala NemX’. All these markers were found to be associated with a major RKN resistance gene, presumably Mi 2 in the resistant line Auburn 634 RNR, suggesting that rkn1 and Mi 2 are either allelic or closely linked. In addition, no susceptible recombinants were found in a resistance screen of 200 F 2 plants from the cross Acala NemX × Auburn 634 RNR. The utility of the two RAPD markers and the converted STS marker were evaluated using 23 R and 8 S germplasm lines. The RAPD and STS markers, along with other previously reported markers associated with RKN resistance will be useful in germplasm screening, MAS for RKN resistance, and map‐based cloning for RKN resistance genes.