Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 22, 2008
Publication Date: March 1, 2009
Citation: Robertson, N.L., Coyne, C.J. 2009. First Report of Bean Yellow Mosaic Virus from Diseased Lupinus luteus L. in Eastern Washington. Plant Disease. 93(3):319. Interpretive Summary: Lupines occur around the world as important plant species in agroecosystems and natural ecosystems with over 165 species in the genus Lupinus (family Fabaceae). The USDA, ARS, Western Regional Plant Introduction Station in Pullman, Washington is responsible for the maintenance, storage, and distribution of 76 lupin species. In 2005, over ninety percent of 307 Lupinus luteus L. transplants on a regeneration site developed severe yellowing, necrosis, and stunting with an estimated 5 % death. A plant virus was extracted from diseased L. luteus and characterized using biological and molecular techniques. The purified preparations contained flexuous particles with a putative coat protein that was serologically related to potyiruses. Sequence analysis of a RT-PCR fragment ~1.7 bp led to the identification of the potyvirus as Bean yellow mosaic virus (BYMV) (GenBank Accession No. EU14420, BYMV-Pullman). Coat protein amino acid percent identities ranged from 96 % to 88 % when compared with 20 BYMV isolates from around the world. Although BYMV has been reported from other crops in Washington, this is the first documentation of a natural infection of BYMV in lupine from Washington. Since BYMV may be seed-borne in lupines, the research results are significant in that they directly contribute toward the maintenance of viable healthy seed for distribution to scientists focusing on lupine research.
Technical Abstract: The USDA, ARS, Western Regional Plant Introduction Station, in Pullman, Washington is responsible for the acquisition, maintenance, storage, and distribution of lupine (genus Lupinus, family Fabaceae). Availability of sufficient quantities of healthy and virus-free seed from lupine collections is mandatory for conducting lupine research. In 2005, at least 90% of Lupinus luteus L. seedlings (276) that were transplanted from the greenhouse to a field plot for seed regeneration developed severe virus-like symptoms with an estimated 5% mortality. Upon testing positive for potyvirus infection by indirect ELISA (Agdia, Inc.), an isolate of Bean yellow mosaic virus (BYMV) was identified from leaf extracts of a diseased plant. Purified preparations contained long flexuous rods (electron microscopy) with a coat protein (CP) ~35 kDa (protein gel) that was serologically positive for potyvirus (western blot). The genomic 3'-end was generated by RT-PCR using universal potyvirus primers, and subsequently cloned and sequenced (GenBank Accession No. EU14423, BYMV-Pullman). The CP amino acid identities ranged from 96 to 88 percent when compared with 20 other BYMV isolates. Experimental plant host range assays from mechanical inoculations of the BYMV-Pullman isolate resulted in transmission to several new lupine host species: L. succulentus Douglas ex K. Koch, L. texensis ‘Bluebonnet’, L. texensis ‘Maroon’). This is the first report of a naturally BYMV infected lupine species in Washington. Since BYMV may be seed-borne in lupines, the research results are significant in that they directly contribute toward the maintenance of viable healthy seed for distribution to scientists focusing on lupine research.