Identification of Phytophthora Species on Phytophthora Blight of Aloe
in October, 1997 and September,1998, Phytophthora blight of Aloe vera L was found in the Aloe Nursery of the Hainan Tropical Crop Tissue Culture Center and a garden of South Chi na University of Tropical Agriculture, Danzhou City, Hainan Province. Infected leaf spots were water soaked and dark green rot at the beginning. A total of 10 isolates were obtained and identi- fied to be Phytophthora nicotianae van Breda de Haan (P.parasitica) according to their morphology and cardinal temperatures. There were 3 mating types among these isolates: A1, A2, and A1A2 (the sex organs of these isolates can be formed by pairing with not only A1 but also A2).