Reactions of field pea cultivars to four races of Fusarium oxysporum f. sp. pisi

Abstract

Reactions of the 117 field pea cultivars available in Canada were evaluated to the four common races (1, 2, 5, and 6) of Fusarium oxysporum Schl. f. sp. pisi (van Hall) Sny. and Hans, the causal agent of fusarium wilt, in growth chambers. Based on the visual assessment of foliar wilt symptoms, 49 cultivars were resistant to at least one of the four races, and the remaining 68 cultivars were susceptible to all four races. Of these resistant cultivars, Ascona and 44 other cultivars were resistant to race 1; Impala to race 2; Aladin to races 1 and 2; and Radley and Princess to races 2, 5, and 6. In an effort to standardize the methodology for screening field pea for resistance to the pathogen, other quantitative parameters including shoot length, vascular discoloration, and shoot and root dry weights were evaluated on selected cultivars. Correlation analysis revealed that foliar wilt symptoms and the reduction in shoot length were highly correlated (r = -0.90, P < 0.01). The result suggests that the reduction in shoot length could be used to supplement the visual severity rating for fusarium wilt in field pea.