光照对黄瓜霜霉病菌孢子囊存活率的影响

Effect of Light to Sporangium Survival of Cucumber Downy Mildew

研究人工控制光照对黄瓜霜霉病菌孢子囊存活率的影响。结果表明:在人工控制条件下,新鲜黄瓜双霉菌孢子囊经紫外光照4h便可失去萌发能力。阳光直接照射2h后,萌发率明显下降;照射4h后,50%的孢子囊失去活力;照射36h后,绝大部分孢子囊失去萌发能力。黑暗条件下,新鲜孢子囊在自然环境中放置5h萌发率开始下降,72h后绝大部分孢子囊完全失去萌发能力;漫射光有利于孢子囊的存活,经漫射光处理的孢子囊存活期长于黑暗条件下存活期。还表明1～2h的短时间光照能促进孢子囊成熟与萌发,从而提高孢子囊的萌发率。

Effect of light under controlled to sporangium survival of cucumber downy mildew was investigated. The results showed that irradiated under Ultraviolet radiation for 4 h,fresh sporangia of P. cubensis would be killed and no sporangia were germinated. Exposure under the direct sun light for 2 h, the germination ratio of sporangia began decreased, more than 50% sporangia were killed after 4 h treatment under direction sunlight, and most sporangia were lost germination ability after 36 h irradiation under directly sun light. In natural conditions, sporangia began lost germination ability in darkness and the life-span was about 72 h in the conditions. Diffusion light or thin light was in favor of the survival of sporangia. The life-span of sporangia under diffusion light was longer than in darkness. The experiment results also showed that the short time irritation promoted the development of fresh sporangia and raised the germination ratio.