A Novel Root-Knot Nematode Resistance QTL on Chromosome Vu01 in Cowpea

G3: Genes, Genomes, Genetics

Jansen R. P. Santos^1,2¹  William C. Matthews^1²  Arsenio D. Ndeve^1³ 

[1] Departamento de Fitopatologia, Universidade de Brasilia, Brasilia, DF, 70910-900 Brazil^2;Department of Botany and Plant Sciences, University of California, Riverside, CA 92521,^3;Deptartment of Nematology^1

关键词: Meloidogyne spp.;    Quantitative Trait Loci;    Vigna unguiculata;   

DOI  :  10.1534/g3.118.200881

学科分类：生物科学（综合）

来源: Genetics Society of America

【 摘 要 】

The root-knot nematode (RKN) species Meloidogyne incognita and M. javanica cause substantial root system damage and suppress yield of susceptible cowpea cultivars. The narrow-based genetic resistance conferred by the Rk gene, present in some commercial cultivars, is not effective against Rk -virulent populations found in several cowpea production areas. The dynamics of virulence within RKN populations require a broadening of the genetic base of resistance in elite cowpea cultivars. As part of this goal, F1 and F2 populations from the cross CB46-Null (susceptible) x FN-2-9-04 (resistant) were phenotyped for M. javanica induced root-galling (RG) and egg-mass production (EM) in controlled growth chamber and greenhouse infection assays. In addition, F families of the same cross were phenotyped for RG on field sites infested with Rk -avirulent M. incognita and M. javanica . The response of F1 to RG and EM indicated that resistance to RKN in FN-2-9-04 is partially dominant, as supported by the degree of dominance in the F2 and F populations. Two QTL associated with both RG and EM resistance were detected on chromosomes Vu01 and Vu04. The QTL on Vu01 was most effective against aggressive M. javanica , whereas both QTL were effective against avirulent M. incognita . Allelism tests with CB46 x FN-2-9-04 progeny indicated that these parents share the same RKN resistance locus on Vu04, but the strong, broad-based resistance in FN-2-9-04 is conferred by the additive effect of the novel resistance QTL on Vu01. This novel resistance in FN-2-9-04 is an important resource for broadening RKN resistance in elite cowpea cultivars.

【 授权许可】

CC BY