Reactions of cultivars of bean (Phaseolus vulgaris L.) to bean common mosaic virus (BCMV)

Abstract

3 plants of each cultivar were raised in pots filled with sterile soil, 451 bean cultivars were tested in all. Inoculum was prepared from 30-day-old plants of P. vulgaris. Seedlings of test varieties were inoculated when 2 weeks old, the inoculum consisted of 14 virus isolates ground in 0.01 m phosphate buffer, pH 7.3 and manually inoculated onto primary leaves of seedlings dusted with 500 mesh carborundum. A cultivar was rated resistant if no systemic infection could be detected and susceptible if it became systemically infected or if the presence of the virus in inoculated leaves of plants without systemic symptoms was demonstrated by virus indexing. Only 68 showed some resistance. The other 383 were found susceptible, with 77 of them expressing systemic necrosis, the remainder showing mosaic symptoms