Genetic mapping of the novel Turnip mosaic virus resistance gene TuRB03 in Brassica napus

Abstract

A new source of resistance to the pathotype 4 isolate of Turnip mosaic virus (TuMV) CDN 1 has been identified in Brassica napus (oilseed rape). Analysis of segregation of resistance to TuMV isolate CDN 1 in a backcross generation following a cross between a resistant and a susceptible B. napus line showed that the resistance was dominant and monogenic. Molecular markers linked to this dominant resistance were identified using amplified fragment length polymorphism (AFLP) and microsatellite bulk segregant analysis. Bulks consisted of individuals from a BC(1) population with the resistant or the susceptible phenotype following challenge with CDN 1. One AFLP and six microsatellite markers were associated with the resistance locus, named TuRB03, and these mapped to the same region on chromosome N6 as a previously mapped TuMV resistance gene TuRB01. Further testing of TuRB03 with other TuMV isolates showed that it was not effective against all pathotype 4 isolates. It was effective against some, but not all pathotype 3 isolates tested. It provided further resolution of TuMV pathotypes by sub-dividing pathotypes 3 and 4. TuRB03 also provides a new source of resistance for combining with other resistances in our attempts to generate durable resistance to this virus.

Mapping and candidate-gene screening of the novel Turnip mosaic virus resistance gene retr02 in Chinese cabbage (Brassica rapa L.)

“…Eight resistance genes have been mapped in Brassica, TuRB01 and TuRB02 , TuRB03 (Hughes et al 2003),…”

“…Most of the genes mapped in brassicas are specific to certain TuMV isolates, being found in B. napus and B. rapa . Most of them are dominant, such as TuRB01 , TuRB03 (Hughes et al 2003), TuRB04-05 (Jenner et al , 2003, and TuRB01b (Rusholme 2000). TuRB01 is a single dominant resistance gene and was the first TuMV resistance gene described in Brassica.…”

“…Molecular markers have been used to position TuMV resistance genes on genetic linkage maps Rusholme 2000;Hughes et al 2003;Rusholme et al 2007), which provide a powerful tool to facilitate marker-assisted selection for This paper describes molecular markers linked to a resistance gene effective against TuMV-C4 in B. rapa and the genetic and physical mapping of the gene retr02 in Chinese cabbage, using the bulked segregant analysis (BSA) approach of Michelmore et al (1991). The candidate TuMV resistance gene is described and sequences from resistant and susceptible plants provided.…”

Double haploids, markers and QTL analysis in vegetable brassicas

“…Populations of DH lines with genetically Wxed status have recombination frequencies that are easy to score, (Kearsey and Farquahar 1998) and 'mapping' populations of DH lines derived from speciWc crosses have been used to develop several published linkage maps of B. oleracea, for example, at Warwick HRI and Birmingham University, two DH populations (the AG population produced from a cross between a DH line A12DHd of B. alboglabra and a DH line GDDH33 derived from the F1 broccoli cv. Green Duke, and the NG population derived from a cross between a DH lines derived from the cauliXower cv.…”

Differential gene expression in incompatible interaction between turnip mosaic virus and non-heading Chinese cabbage

“…TuRB03 was mapped on chromosome N6 in B. napus (cv. Westar), which was verified to be dominant and monogenetic by segregation analysis of a backcross generation (Hughes et al 2003). TuRB04 and TuRB05 are single dominant TuMV resistance loci, as validated by the examination of plant phenotypes induced by TuMV inoculation in B. napus line 165.…”