INHERITANCE OF RESISTANCE TO THE NL-8 STRAIN OF BEAN COMMON MOSAIC-VIRUS IN PISUM-SATIVUM

The NL-8 strain of bean common mosaic virus (BCMV-NL8) can infect Pisum sativum systemically without causing appreciable symptoms. The presence of the virus in susceptible genotypes can be ascertained by enzyme-linked immunosorbent assays (ELISA) or indicator hosts. Resistance to BCMV-NL8 was found in domestic cultivars known to be resistant to bean yellow mosaic virus (BYMV) and five other viruses. In crosses involving the multiresistant cultivar Bonneville and two susceptible lines, resistance to BCMV-NL8 was conferred by a single recessive gene, to which the symbol bcm is tentatively assigned. This gene is closely linked to a cluster of other resistance genes present on chromosome 2, conferring resistance to BYMV, clover yellow vein virus, pea mosaic virus, lentil strain of pea seed-borne mosaic virus, and watermelon mosaic virus 2. BCMV-NL8 was not detected in seeds of seven pea lines systemically infected with this virus.