Development of Erysiphe pisi on some pea (Pisum sativum) cultivars and on non-hosts

Early development of Erysiphe pisi on the leaves of susceptible and resista nt pea cultivars/lines and on some non-hosts was studied by light microscop y. E. pisi conidia germinated and formed appressoria on both resistant and susceptible leaves of pea. However, further development was stopped on the leaves of resistant cultivars/lines as mostly only one germ tube was produc ed at 48 h after inoculation. Though papillae formation was there at the si te of penetration in both resistant and susceptible pea leaves, it was prom inent in the susceptible pea leaves. Failure of development was mostly asso ciated with hypersensitive: death of the attacked cells. While E. pisi fail ed to produce multiple germ rules on a number of non-hosts, less than 1 % o f conidia produced multiple germ tubes (From 1-4, uni- and bipolarly) on le aves of a fern (Nephrolepis cordifolia).