Reactions of field pea varieties to three isolates of Uromyces fabae

Xue, A.G. and Warkentin, T. D. 2002. Reactions of field pea varieties to three isolates of Uromyces fabae. Can. J. Plant Sci. 82: 253-255. Reactions of 93 field pea varieties to three isolates of Uromyces fabae (Pers.) de Bary (Uf-1, Uf-2, and Uf-3) were measured as leaf area with symptoms (LAS) under controlled environmental conditions. Significant differences (P < 0.05) were observed from pea varieties and rust isolates, and variety x isolate interaction. Of these varieties, Tara and Century were most resistant (LAS <2%) to both Uf-1 and Uf-3 isolates; Victoria and Topper were most resistant to Uf-2 only; and Titan, Tipu, Emerald, and Yellowhead were most resistant to Uf-3 only. The remaining varieties had LAS of 2-67% for Uf-1, 2-86% for Uf-2, and 2-45% for Uf-3, and were considered susceptible to the respective isolates. Over the average of 93 varieties, Uf-3 had LAS of 8.6% and was considered a less virulent isolate compared to Uf-1 (16.2%) and Uf-2 (15.2%). It is suggested that several different pathogenic isolates are required to test pea lines for rust resistance. A growth room inoculation and assessment method was developed in this study and can be used for evaluating pea lines for susceptibility to U. fabae.