|Authors: ||N. Yang, G. Reighard, K. Gasic, D. Ritchie, W. Okie|
|Keywords: ||SSR marker, leaf, fruit, QTL, disease|
Bacterial spot, caused by Xanthomonas arboricola pv. pruni, is a serious disease that can affect peach fruit quality and production worldwide.
This disease causes severe defoliation and blemishing of fruit, particularly in areas with high rainfall, strong winds, high humidity and sandy soil.
The molecular basis of its tolerance and susceptibility in peach is yet to be understood.
To study the genetics of the peach in response to bacterial spot, an F2 segregating population between two peach cultivars, ‘Clayton’, a resistant phenotype, and ‘O’Henry’, which is very susceptible to bacterial spot, was created.
Phenotypic data for leaf and fruit response to bacterial spot infection were collected at two locations: the Sandhills Research Station, Jackson Springs, North Carolina (NC); the Sandhill Research and Education Center, Pontiac, South Carolina (SC). Out of 574 SSR markers developed in Prunus, only 7% (38) were informative among parents and used to develop a framework genetic linkage map.
Markers based on the NBS-LRR (nucleotide binding site, leucine-rich repeat) resistance gene analogs were developed to increase the map density.
Single marker analysis indicates several interesting markers highly associated (P<0.001) with the bacterial spot resistance trait.
Kruskal-Wallis and Simple Interval Mapping revealed one putative QTL associated with low incidence of bacterial spot located on LG4. Marker-assisted selection for bacterial spot resistance will be discussed.
Download Adobe Acrobat Reader (free software to read PDF files)