Resistance in Faba Bean (Vicia faba) to Bean Yellow Mosaic Virus. I. P. S. Gadh, Graduate Student, Department of Plant Science, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2. C. C. Bernier, Professor, Department of Plant Science, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2. Plant Dis. 68:109-111. Accepted for publication 7 August 1983. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-109.

Sixty-eight open-pollinated faba bean selections resistant to bean yellow mosaic virus (BYMV) in preliminary field experiments were evaluated further in the field from 1978 through 1981. The selections were inoculated with the “mosaic” strain of BYMV mechanically and by exposure to viruliferous pea aphids (Acyrthosiphon pisum) in separate experiments. Most selections were heterogeneous for disease reaction. Repeated testing and reselection increased the number of symptomless plants in the progeny of accessions 2N138, 2N23, 2N295, and 2N85. The number of resistant (symptomless and mild mosaic) plants also increased in the progeny of accessions 2N101, 2N65, and 2N425. One hundred twenty-five selections from the 1978 field trials were evaluated further and self-pollinated in the greenhouse in 1978 and 1979; inbred lines from accessions 2N138, 2N295, 2N23, 2N65, 2N76, and 2N2 were symptomless. All plants of the inbred line from accession 2N138 remained symptomless in aphid-inoculated field trials. Five additional lines had 70–90% symptomless plants. When superior selections and inbred lines were inoculated with the “necrotic” strain of BYMV, only accession 2N138 was immune under field and greenhouse conditions. In addition, many selections and inbred lines were heterogeneous with a few plants resistant to both virus strains.