GENETIC-ANALYSIS OF BROAD-SPECTRUM RESISTANCE TO POTYVIRUSES USING DOUBLED HAPLOID LINES OF PEPPER (CAPSICUM-ANNUUM-L)

Genetic analysis of resistance to PVY in androgenetic doubled haploid lines, F1, F2 and backcross progenies of the Mexican pepper line, CM 3 34 (Capsicum annuum L.), was performed. Three reaction types were obse rved when seedlings were inoculated with several PVY strains of differ ent pathotypes and with an American PeMV strain. Resistant genotypes n ever showed systemic symptoms although some individuals sporadically d eveloped necrotic local lesions on inoculated cotyledons. Susceptible genotypes exhibited either a typical systemic mosaic or a systemic nec rosis that caused the death of the inoculated seedlings. Segregation a nalyses indicated that resistance to pepper potyviruses in CM 334 is c onferred by two genes. The first one, tentatively named Pr4, is domina nt and confers the resistance to all now known pathotypes of PVY and t o PeMV. The second one, tentatively named pr5, is recessive; it confer s only the resistance to common strains of PVY. The systemic necrotic response is conferred by an independent dominant gene, tentatively nam ed Pnl.