COMPARATIVE POTYVIRUS HOST RANGE, SEROLOGY, AND COAT PROTEIN PEPTIDE PROFILES OF WHITE LUPIN MOSAIC-VIRUS

A potyvirus isolated from white lupin (Lupinus albus) plants with severe mosaic symptoms was purified; compared with other selected potyviruses in terms of host range, serology, and coat protein peptide profiles; and found to be distinct. Accordingly, it has been assigned a new name, white lupin mosaic virus (WLMV). In reciprocal enzyme-linked immunosorbent assays with polyclonal antisera, WLMV behaved similarly to the Scott isolate of bean yellow mosaic virus (BYMV) and was distinguishable from the PMV-1 isolate of pea mosaic virus and the Pratt isolate of clover yellow vein virus (CYVV). In preliminary host range and pathogenicity tests, however, WLMV was distinct from BYMV, lacking the capacity to infect standard BYMV-susceptible cultivars of bean (Phaseolus vulgaris) and attacking BYMV-resistant cultivars of pea (Pisum sativum). When tested against a panel of 22 potyvirus-differentiating monoclonal antibodies, WLMV evidenced an absence Of two epitopes common to all examined members of the BYMV subgroup of potyviruses and the presence of one epitope not previously known among BYMV subgroup members. In comparisons of trypsin digests of WLMV coat protein by high-performance liquid chromatography with those of other selected potyviruses, peptide profiles of WLMV most closely resembled a severe isolate (BYMV-S) of BYMV, but the terminal regions of its coat protein structure were distinctive.