UNILATERAL COMPATIBILITY OF GENOME SEGMENTS FROM 2 DISTINCT STRAINS OF RED-CLOVER NECROTIC MOSAIC-VIRUS

Two strains of red clover necrotic mosaic virus (TpM 34 and TpM 48) were distinguished by their serological relationship, by the symptoms they induced in selected host plants and by Northern hybridization analysis. Purified RNA 1 and RNA 2 of the two strains were inoculated to the leaves of Chenopodium amaranticolor, Vigna unguiculata and C. quinoa in all possible combinations. It was demonstrated that a heterologous mixture containing RNA 1 of TpM 34 and RNA 2 of TpM 48 was infectious, resulting in lesion development whereas the reciprocal combination was not. The infectious pseudorecombinant was isolated by several single lesion transfers in C. quinoa and its genetic nature was confirmed by serology and Northern hybridization analysis. Inoculation of the pseudorecombinant and the two parental strains of five selected host plants revealed that symptom expression was determined by RNA 1.