轮纹病菌在苹果枝干上侵入途径的扫描电镜观察

对富士苹果枝干轮纹病在不同部位发生频率进行了调查,并用轮纹病菌(Botryosphaeria berengriana f.piri- cola)对富士苹果一年生枝条进行室内接种,保湿处理,在接种后不同时期采样通过扫描电镜对轮纹病菌在苹果枝条 上的侵入途径进行观察。结果表明,枝干轮纹病病斑在皮孔部位发病频率为92％,非皮孔部位为8％。扫描电镜观察 表明,保湿条件下轮纹病菌接种4 h后即可萌发形成侵染菌丝侵染苹果枝条,其可通过枝条皮孔、表面伤口及表皮缝 隙进行侵入,但皮孔是最主要的侵入途径;24 h内分生孢子基本可完成从吸附、萌发到侵入的过程。

Observation of infection approach of Botryosphaeria berengriana f.piricola on apple stem under scanning electron microscope

In this study the occurrence frequency of ring rot disease in different part of Fuji stems were investigated and scanning electron microscope was applied to observe the infection approach of Botryosphaeria berengriana f. piricola on Fuji stems in different time after inoculation. The results showed that the occurrence of ring rot disease was 92% in lenticels and 8% not in lenticel. The observations with scanning electron microscope revealed that spores of B. berengriana f. piricola germinated and produced infection hyphae 4 h after inoculation under humid condition, then the infection hyphae infected apple stem through lenticel, wound and epidermis gap. The lenticel was the uppermost infection approach. Spores finished the process of attachment, germination and infection in 24 h after inoculation.