| 【Objective】Pepper anthracnose caused by Colletotrichum acutatum is an important factor restricting the pepper industry in Nanxiong, Guangdong Province. The biological characteristics of C. acutatum were studied to provide references for the control of pepper anthracnose.【Method】The pathogenicity of C. acutatum to different kinds of peppers were determined by artificial inoculation. The effects of temperature, pH, light, medium, carbon source, nitrogen source on C. acutatum were measured by mycelium growth method and microscopic examination.【Result】C. acutatum was pathogenic to red cluster pepper, line pepper, bell pepper, spiral pepper, beauty pepper, yellow skin pepper, green skin pepper, wrinkled skin pepper and pickled pepper. Among nine kinds of peppers, line pepper was more sensitive to C.acutatum and it could be infected without wounds. The suitable temperature for mycelium growth of C. acutatum was 24-28 ℃ . Mycelium growth was the fastest at 26 ℃ , and spore quantity was the largest at 30 ℃. The suitable pH for mycelium growth and spore production was 5.0 - 9.0. Different light conditions had little effect on mycelium growth, but light promoted spore production. The optimum medium for mycelium growth was PDA. Pepper fruit juice medium promoted spore production. Soluble starch, glucose and mannitolare were beneficial to mycelium growth and spore production, while sucrose was good for mycelium growth but bad for spore production. Organic nitrogen source beef extract was optimum to mycelium growth and spore production. 【Conclusion】C. acutatum was highly pathogenic to different kinds of peppers, and it could infected line pepper without wounds. The biological characteristics of C. acutatum were different from those of C.gloeosporioides and C.capsici. |
