Submitted to: Plant Disease
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/3/2001
Publication Date: 9/1/2001
Citation: Gillaspie, Jr., A.G. Resistance to cucumber mosaic virus in cowpea and implications for control of cowpea stunt disease. Plant disease, 2001. Plant disease 85: 1004-1005 (2001). Interpretive Summary: Cowpea stunt disease is the most severe disease of cowpeas in the southeastern US. This disease is caused by a interaction of two viral diseases, Cucumber mosaic virus (CMV) and Blackeye cowpea mosaic virus (B1CMV). Resistance to B1CMV in cowpeas is available in a number of lines, but no resistance is known for CMV. A white-seeded selection from the germ mplasm line PI 441918 was found to be resistant to CMV and immune to B1CMV. This line is of potential value for breeding cowpea lines with more stunt resistance.
Technical Abstract: Cucumber mosaic cucumovirus (CMV) and Blackeye cowpea mosaic potyvirus (B1CMV) interact synergistically in dually infected plants of Vigna unguiculata to cause cowpea stunt disease, the most damaging viral disease of cowpea in the US. Sources of resistance to B1CMV are known and are present in cowpea cvs such as Pinkeye Purple Hull-BVR. However, no sources sof CMV resistance in cowpea have been found. In 1998, a cowpea line, PI 441918, was found in regeneration plots that did not have many viral symptoms, did not contain B1CMV, and had a low titer of CMV as judged by DAC-ELISA. Greenhouse tests showed that infection with CMV produced a lower titer of virus in plants arising from light colored seeds of the PI than plants from dark colored seeds or from a susceptible cv. Coronet. Studies in field plots with CMV - and B1CMV infected Coronet plants as spreader rows showed no infection in the light-seeded plants with B1CMV and da low infection rate with CMV as determined by ELISA. This line offers th high level of B1CMV resistance along with the moderate CMV resistance needed for a parental line to develop stunt resistant cultivars.