Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 3, 2000
Publication Date: August 1, 2001
Interpretive Summary: Cucumber mosaic virus infects and causes severe losses in pepper production worldwide. Pepper varieties with the ability to completely resist infection by CMV are not yet commercially available. The identification of cultivated varieties or wild relatives of pepper that are better able to fend off attack by viral pathogens such as cucumber mosaic virus is a critical first tstep towards developing resistant varieties. This study shows that over 73 percent of plants from the pepper accession Capsicum frutescens 'BG2814-6' were not infected by cucumber mosaic virus. Standard varieties were completely infected, and over 93% of the most tolerant pepper variety currently available, Capsicum annuum 'Perennial', were partially infected. This study describes the inheritance of the observed resistance in 'BG2814-6', showing that resistance is controlled by at least two genes. At least one of these genes appears to be the same as one of the genes in 'Perennial'. Although 'BG2814-6' is commercially unacceptable due to its very small, extremely pungent fruits, the transfer of the genes conferring virus resistance into other, more acceptable, pepper varieties is now possible and is under way. The identification of new genotypes with resistance to cucumber mosaic virus, as well as information about the number and types of genes controlling the resistance, provide important tools for the development of commercially desirable resistant varieties.
Technical Abstract: A small-fruited pungent pepper accession, Capsicum frutescens 'BG2814-6', is resistant to several isolates of cucumber mosaic virus (CMV). Resistance in 'BG2814-6' is incompletely penetrant and is controlled by at least two major recessive genes. 14-6 and C. annuum 'Perennial', the leading source of CMV tolerance/resistance appear to share one or more CMV resistance genes. CMV was detected in uninoculated leaves in a small percentage of both 14-6 and Perennial plants, indicating that resistance is not absolute in either genotype. ELISA absorbance values of samples taken from inoculated leaves corresponded well with visible viral symptoms for parental genotypes. While Perennial accumulated CMV antigen in inoculated leaves, CMV antigen was not detected in inoculated leaves of many 14-6 plants, suggesting that there may be mechanistic difference in resistance between the two genotypes.