New Source of Resistance to Cucumber mosaic virus in Capsicum frutescens

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. The accession BG2814-6 and C. annuum 'Perennial', the leading source of CMV tolerance, appear to share one or more CMV resistance genes. CMV was detected in uninoculated leaves in a small percentage of both BG2814-6 and Perennial plants, indicating that resistance is not absolute in either genotype. Enzyme-linked immunosorbent assay absorbance values of samples taken from inoculated leaves corresponded well with visible viral symptoms for parental genotypes. While Perennial plants accumulated CMV antigen in inoculated leaves, CMV antigen was not detected in inoculated leaves of 73% of BG2814-6 plants, suggesting that there may be a mechanistic difference in resistance between the two genotypes.

Keywords: cucumovirus; disease resistance; pepper; polygenic resistance.