A major QTL corresponding to the Rk locus for resistance to root-knot nematodes in cowpea (Vigna unguiculata L. Walp.)

Autor: Arsenio Ndeve, Jansen R. P. Santos, W. C. Matthews, Bao-Lam Huynh, Philip A. Roberts, Jeffrey D. Ehlers, Timothy J. Close, Mitchell R. Lucas
Jazyk: angličtina
Rok vydání: 2015
Předmět:
Zdroj: TAG. Theoretical and Applied Genetics. Theoretische Und Angewandte Genetik
TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik, vol 129, iss 1
ISSN: 1432-2242
0040-5752
Popis: Key message Genome resolution of a major QTL associated with the Rk locus in cowpea for resistance to root-knot nematodes has significance for plant breeding programs and R gene characterization. Abstract Cowpea (Vigna unguiculata L. Walp.) is a susceptible host of root-knot nematodes (Meloidogyne spp.) (RKN), major plant-parasitic pests in global agriculture. To date, breeding for host resistance in cowpea has relied on phenotypic selection which requires time-consuming and expensive controlled infection assays. To facilitate marker-based selection, we aimed to identify and map quantitative trait loci (QTL) conferring the resistance trait. One recombinant inbred line (RIL) and two F2:3 populations, each derived from a cross between a susceptible and a resistant parent, were genotyped with genome-wide single nucleotide polymorphism (SNP) markers. The populations were screened in the field for root-galling symptoms and/or under growth-chamber conditions for nematode reproduction levels using M. incognita and M. javanica biotypes. One major QTL was mapped consistently on linkage group VuLG11 of each population. By genotyping additional cowpea lines and near-isogenic lines derived from conventional backcrossing, we confirmed that the detected QTL co-localized with the genome region associated with the Rk locus for RKN resistance that has been used in conventional breeding for many decades. This chromosomal location defined with flanking markers will be a valuable target in marker-assisted breeding and for positional cloning of genes controlling RKN resistance. Electronic supplementary material The online version of this article (doi:10.1007/s00122-015-2611-0) contains supplementary material, which is available to authorized users.
Databáze: OpenAIRE