reaction of different cucurbita species to phytophthora capsici, p. melonis and p. drechsleri under greenhouse conditions

the reaction of nineteen different cultivars of cucurbita spp. including cucurbita pepo, cucurbita maxima and lagenaria siceraria to phytophthora capsici, phytophthora melonis and phytophthora drechsleri was studied under greenhouse conditions. plants were grown in steam sterilized soil. one-month-old plants were inoculated with vermiculate hempseed extract inocula of phytophthora and were flooded for 24 hours. the activity of the pathogens was monitored during the experiment by using citrus leaf discs. seedling mortality was monitored two months after inoculation. none of the species were infected with p. drechsleri or p. melonis. cucurbita maxima cultivars hamedan and ace south korea, c. pepo cultivar shabestar and lagenaria siceraria were not infected with p. capcisi. the possibility of using these cultivars as root stocks for grafting against phytophthora species is discussed.