|Yang, Nannan -|
|Reighard, Gregory -|
|Ritchie, David -|
|Gasic, Ksenija -|
Submitted to: HortScience
Publication Type: Abstract Only
Publication Acceptance Date: May 1, 2010
Publication Date: August 5, 2010
Citation: Yang, N., Richard, G.L., Richie, D., Okie, W.R., Gasic, K. 2010. Construction of a genetic linkage map for identification of molecular markers associated with resistance to Xanthomonas arboriciola pv. pruni in peach [Prunus persica (L.) Batsch][abstract]. HortScience. 45(8):S304. Interpretive Summary: One of the most serious diseases of peach in the southeast US is bacterial spot disease. This disease causes leafspot and leaf drop, as well as fruit spot, and is expensive to control. It can make fruit unmarketable in bad years. This project established genetically identical plantings in GA, SC and NC of seedlings from a cross of OHenry (very susceptible) x Clayton (very resistant). After rating these trees for disease resistance or susceptibility, it will be possible to study the DNA and find molecular markers associated with the trait. This will allow screening of greenhouse seedlings for the resistance, so susceptible trees can be discarded before planting in the orchard. The process will greatly enhance the process of breeding for resistance and ultimately provide better varieties for commercial and home growers.
Technical Abstract: Bacterial spot, caused by Xanthomonas campestris pv. pruni, is a serious disease that can affect peach fruit quality and production. The molecular basis of its tolerance and susceptibility is yet to be understood. To study the genetics of the peach in response to bacterial spot, an F2 population of 188 individuals from a cross between Clayton, a resistant phenotype, and O’Henry, which is very susceptible to bacterial spot, was created. Four hundred and thirty-two SSR markers already mapped in Prunus were tested for their polymorphism. Only 25% (108) were informative and were used in development of a genetic linkage map. The F2 population was planted at three locations: the Sandhills Research Station, Jackson Springs, NC; the Sandhill Research and Education Center, Pontiac, SC; and the ARS-USDA Southeastern Fruit and Tree Nut Laboratory at Byron, GA. Field data for response to bacterial spot infection were collected three times a year from two locations, NC and SC. Preliminary data indicate involvement of one or two major genes in peach having resistance to bacterial spot leaf infection. The genetic map in combination with field data will be used to locate the region(s) in the genome associated with bacterial spot resistance. Marker-assisted selection for bacterial spot resistance will be discussed.