New sources of resistance to Phytophthora capsici in Capsicum spp.

Phytophthora blight caused by Phytophthora capsici is a dangerous disease in pepper that may devastate the crop unless properly controlled when environmental conditions are favorable for outbreak of the disease and the varieties grown are susceptible. Although many pepper varieties released nowadays are resistant to the disease to a certain degree, continuous search for sources of resistance to the disease is necessary to cope with buildup of virulence and pathotype specialization against the resistance genes deployed. Two hundred accessions of pepper germplasm received from the RDA gene bank, and 17 accessions received as sources of resistance to P. capsici from the University of Georgia (UG) were grown for seed increase in 2011. The accessions successfully increased and some others were tested for resistance against a highly virulent strain (Pc018) of P. capsici isolated from an infected plant of a resistant commercial cultivar in Youngyang from 2011 to 2012. The PI201237-3, PI201237-4, PI566811-1, PI566811-2, PI593573-1, PI593573-3, and PI640532-1 of the UG accessions, KC00807-1 and KC01744 of C. chinense, KC00937 received from National Horticultural Research Institute in 2003, and KC01322 introduced from Laos in 2007 were resistant enough to exploit for breeding resistance. The resistance sources are new additions to the sources of resistance to P. capsici, tested to domestic strain of P. capsici and readily available in Korea.