A Reliable Method for Phytophthora cajani Isolation, Sporangia, Zoospore Production and in Planta Infection of Pigeonpea

Abstract

Pigeonpea (Cajanus cajan L.) is an important legume crop of rainfed agriculture. High levels of protein in pigeonpea make it a valuable protein source for developing countries. Phytophthora blight caused by Phytophthora cajani (P. cajani) is a potential threat to pigeonpea (Cajanus cajan L.) production, affecting the crop irrespective of cropping system, cultivar grown and soil types (Pande et al., 2011; Sharma et al., 2006). The primary mode of infection of P. cajani is sporangium and zoospore. Therefore, sensitive and reliable methods for zoospore production and estimating infection severity are desirable in case of Phytophthora blight of pigeonpea (Sharma et al., 2015). Here we present a protocol for isolation of P. cajani from infected plants, sporangia and zoospore production and in planta infection technique of pigeonpea seedlings. These methods will be important tool to devise a platform for rapid and reliable screening against Phytophthora blight disease of pigeonpea as well as for host x pathogen x environment interaction studies.