Morphological differentiation of Venturia species infecting different pome and stone fruits in Jammu and Kashmir, India

Scab disease caused by Venturia spp. is a major threat to pome and stone fruit crops which are grown extensively under the temperate climate of Jammu and Kashmir in India, affecting economy of commercial growers. To gain insights into the establishment and spread of the pathogen, it is essential to have a clear understanding of its life cycle, in which the presence or absence of the sexual stage holds considerable importance. The in-vivo and in-vitro morphological differentiation of three Venturia species viz.; Venturia inaequalis, Venturia pyrina, Venturia carpophila revealed that there were significant differences within their morpho-cultural characteristics. However, Venturia carpophila infecting both almond and peach showed insignificant variations in both in vivo and in vitro conditions. Importantly, the teleomorph was only observed in V. inaequalis, which emphasizes that there might be high genetic variation in the pathogen population. Surprisingly, no teleomorph of V. pyrina and V. carpophila was found, which may be related to the fact that both of these pathogen species overwinter as dormant mycelia and conidia under temperate conditions of North Western Himalayas.