Host range of Phytophthora capsici, the causal agent of tomato crown and root rot in Fars province

This research was performed to determine the host range of tomato isolates of Phytophthora capsici، among other common crops in Fars province. Seeds of tomato، squash، cucumber، melon، pepper، watermelon، pea، french bean، onion، carrot، corn، cantaloupe، eggplant، and wheat were sown in sterilized soil and kept in a greenhouse. Seedlings were inoculated by adding 50 ml of a zoospore suspension (1×105 spores per ml) of Ph. capsici onto the soil surface around the stem of each plant in the pot. Plants were kept in a growth chamber. Disease incidence was measured three times at 5، 10، 15 days post inoculation. Twelve of the tested plant species became infected with Ph. capsici and developed symptoms including crown and root rot، and yellowing، which led to plant death after two weeks. Ph. capsici was re-isolated from all symptomatic plants. Tomato، squash، cucumber، melon، pepper، watermelon، cantaloupe and eggplant were the most susceptible، while، pea، french bean، onion، carrot and sugar beet were less susceptible to the pathogen. Wheat and corn did not show any disease symptoms and were considered as non-hosts. The results of this study showed that common Poaceae crops in Fars province are non-host to Ph. capsici and can be used in crop rotation for disease management.