|Study on Biological Characteristics of Colletotrichum acutatum in Pepper
|中文关键词: 辣椒炭疽病 尖孢炭疽菌 生物学特性 致病性
|英文关键词: pepper anthracnose Colletotrichum acutatum biological characteristics pathogenicity
| 【目的】由尖孢炭疽菌引起的辣椒炭疽病是制约广东南雄辣椒产业的重要因素，对病菌生物学特性进行研究，旨在为辣椒炭疽病的防治提供参考。【方法】通过人工接种测定尖孢炭疽菌对不同种类辣椒的致病性，采用菌丝生长法和镜检孢子量测定温度、pH、光照、培养基、碳源和氮源对尖孢炭疽菌的影响。【结果】尖孢炭疽菌对指天椒、线椒、柿椒、螺丝椒、美人椒、黄皮洒椒、绿皮尖椒、皱皮椒、泡椒均有致病性，其中线椒对尖孢炭疽菌更为敏感，不需要伤口就可被侵染为害。适合尖孢炭疽菌菌丝生长的温度为 24~28 ℃，26 ℃时菌丝生长最快，30 ℃时产孢量最大；适宜生长和产孢 pH 为 5.0~9.0；不同光照条件对菌丝生长影响差异不大，但光照促进孢子产生。PDA 利于菌丝生长，辣椒果煎汁培养基促进孢子产生；可溶性淀粉、葡萄糖和甘露醇利于病菌生长和孢子产生，蔗糖利于菌丝生长但不利于产孢。有机氮源牛肉膏培养基最利于病原菌菌丝生长和产孢。【结论】尖孢炭疽菌致病性强，可在无伤口下侵染线椒，其生物学特性与胶孢炭疽菌和辣椒炭疽菌存在种间差异。
| 【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.