寡雄腐霉分泌物对植物病原真菌的抑制作用及其对番茄灰霉病的防治效果

为了探明寡雄腐霉分泌物中小分子量物质对病原真菌的作用,应用玻璃纸法和生长速率法测定了分子量小于8 kD的寡雄腐霉分泌物对9种植物病原真菌菌丝生长的抑制作用。结果表明,分子量小于8 kD的寡雄腐霉分泌物能强烈抑制森禾腐霉、灰葡萄孢、黄色镰刀菌的菌丝生长,抑菌率分别达到88．9%、86．7%和84．6%;对供试的4种腐霉以及尖孢镰刀菌的4个专化型的抑菌率均达显著性差异。在扫描电镜下可见,经寡雄腐霉分泌物处理的灰葡萄孢菌,菌丝细胞壁破裂、穿孔、干瘪,且菌丝分化出的分生孢子梗少,产孢量明显下降。温室盆栽试验表明,寡雄腐霉滤液对番茄灰霉病具有显著的预防保护作用与治疗作用,其预防保护作用与杀菌剂多菌灵1000倍的防治效果达到同一显著水平。

Inhibitory effect of the secretion of Pythium oligandrum on plant pathogenic fungi and the control effect against tomato gray mould

In order to investigate the effect of the molecular weight less than 8 kD secretion of Pythium oligandrum on plant pathogenic fungi, the inhibition effect on 9 species total 16 isolates of plant patho- genic fungi was tested on Petri dishes with cellophane paper and growth rate methods, The secretion of P. oligandrum distinctly depressed the mycelia growth of P. sylvaticum, Botrytis cinerea, and Fusarium cul- morum with inhibition rates of 88.9%, 86.7% and 84.6%, respectively. The inhibition rates of four Pythium species and four formae speciales of F. oxysporum were significant difference (P=0.05), re- spectively. The morphology of B. cinerea treated with the secretion of P. oligandrum was abnormal under scanning electron microscope with mycelia shriveled, small spores appeared in the cell wall and spore output reduced significantly. In the greenhouse trial, the filtrate of P. oligandrum had significantly pro- tective and curative effect against tomato gray mould, and the protective effect of the filtrate was equiva- lent strong with carbendazim 1000 times dilution.