Study On The Hyperparasite Of Colesporium Phellodendri

Phellodendron amurens is a valuable medicinal plant. The rust of P. amurens caused by Colesporiurn phellodendri was one of the most important diesease of P. amurens. We found that a parasitic fungus attacked uredium of C. phellodendri. This paper reported the hyperparasitism, the development of natural hyperparasitism, the identification of hyperparasite, the biological characters and soluble protein, isoesterase patterns of the hyperparasites. The study of this hyperparasite may provide scientific base for biological control.The hyperparasites attack uredium of the pathogen and hinder the development of uredium and the release of uredispores. Hyperparasitism of C. phellodendri began in the end of July or early August then peaked in the middle of September. The natural hyperparasitism was very popular in ya'an district. In some areas the hyperparasitic percentage reached 100% and hyperparasitic index was from 60 to 100. The hyperparasite was identified as Ramularia sp.. The discovery of this hyperparasite may provide potentials for biological control.The cultural characters, and effect of temperature, PH, carbon source and nitrogen source on the mycelial growth and spore production of Rarnularia sp. were tested. The results indicated that the cultural type, the rate of mycelial growth and the sporulation of Ramularia sp. were various. The range of tmeperature for mycelium growth was 5～30℃, and the optimum tmeperature was 20～25℃. The range of pH for mycelium growth was 3.0～10.0, and the optimum pH was 6.0～8.0. The optimum tmeperature and pH for spore production was 25℃and 7.0 respectively. The most suitable carbon source and nitrogen were glucose, KNO₃ and NaNO₃ respectively, and inulin, KNO₃, NaNO₃ were suitable for spore production.The optimum temperature, PH and relative humidity for the spore germination were 25-30℃, pH7.0, in drops of water, respectivel. The death temperature for the spore was 43℃(10min). The survival time of conidiospore of C. phellodendri was about foure monthes.Soluble protein and isoesterase electrophoresis pattems of Ramularia sp. from different locations in ya'an were smdued by polyacrymide gel vertical electrophoresis. The species specific protein and eserase bands of Ramularia sp. were found. The results could be used in classification as an additional taxonomic criterion to distinguish the specie.