Working group session:
Structural Genomics
Presentation type:
oral
Authors:
Chee, Peng
Presenter:
Chee, Peng
Correspondent:
Chee, Peng
Abstract:
The development and use of cultivars with resistance to RKN offers the best management tool for RKN. In our earlier study, by using the bulk segregant approach, we identified a major QTL on Chr.11 associated with the resistant phenotype in M-120 RNR. The objectives of this study are to re-evaluate the genetics of the resistance to RKN in the resistant line M-120 RNR using newly developed SSR markers. QTLs analysis revealed that in addition to the previously reported locus on Chromosome 11, a major QTL was present on chromosome 14 with a LOD score of 9.462 and accounted for 31.90% PV. Therefore, our data suggests that there are two major genes controlling root-knot nematode resistance in M-120 RNR. Interestingly, while the resistant allele on Chr. 11 is derived from Clevewilt-6, the resistance allele on Chr. 14 is originated from Wild Mexican Jack Jones. In addition, the gene on Chr. 11 appears to mostly affect gall suppression while that on Chr.14 appears to reduce eggs production but has little effects on root galling. Therefore, it is possible that the transgressive segregation in Auburn 623RNR source, which include the M120 RNR parent used in the current study, is due to the stacking of genes from two moderately resistant parents with different mechanisms for resistance.