鹿蹄草素对梨采后黑斑病病原菌的抑制作用

Inhibitory effect of Pyrolin on Alternaria alternata causing occurrence of black spot in postharvest pear

为研究鹿蹄草素对梨采后黑斑病病原菌的抑制作用以达到防腐保鲜的目的,采用生长速率法测定了鹿蹄草素对链格孢菌(Alternaria alternata)菌丝体生长的抑制作用;通过梨果实创伤接种病原菌试验,测定了鹿蹄草素对梨采后黑斑病的防治效果;并用扫描电镜和透射电镜观察鹿蹄草素对链格孢菌超微结构的影响。结果表明,鹿蹄草素对链格孢菌表现出较强的抑制作用,且浓度越高,抑制作用越强,当鹿蹄草素浓度为2.50、5.00g/L时抑菌率均达到了100%;鹿蹄草素对链格孢菌在梨果实上的发生和蔓延有着不同程度的抑制和延缓作用;扫描电镜下可见,处理菌丝扭曲变形,表面粗糙、局部凹陷,菌丝间相互黏连,菌丝断裂,内容物外漏;透射电镜下可见,处理菌丝细胞结构不规整,胞质不均匀,出现质壁分离现象,细胞内部组成紊乱,内含物减少,出现大量电子空白区。

In order to explore the inhibitory effect of pyrolin on Alternaria alternata causing occurrence of black spot in postharvest pear fi＇uit, agar plate test was conducted to test the inhibitory effect in vitro of pyrolin.Fresh pears were used inoculated with A lternaria alternata for studying its effect of inhibitory capacity on the lesion development.The uhrastructure of A lternaria ahernata treated by pyrolin was observed through scanning electron microscope （SEM） and transmission electron microscope （TEM）. The results showed that pyrolin had obvious inhibitory effect in vitro on A lternaria alternata and the action was significantly increased when applied concentration was higher. The inhibitory rate reached 100% when concentrations of pyrolin were 2.5 g/L and 5.0 g/L. And pyrolin had different inhibitory effects against the occuring and spreading of black spot in postharvest pears. Observation under SEM revealed that the mycelium became warped ,deformed and adhered together,cell surface was coarse and sunken,the mycelium was ruptured,inner cytoplast was leakage-induced.The cell structure was irregular, cytoplasm was non-uniformity, internal composition was in disorder, the phenomenon of the plasmolysis occurred, the contents decreased, and many areas of electron blank appeared with TEM observation.