石楠拟盘多毛孢致病毒素除草作用的初步研究

石楠拟盘多毛孢(Pestalotiopsis photiniae)是草莓根腐病的优势致病菌,主要通过毒素引发病害。为明确该病菌毒素对常见几种杂草的影响,本试验利用离体叶片和种子根芽伸长法研究了该病菌粗毒素对几种杂草的致病作用。结果表明:该粗毒素对供试的13种杂草叶片均有不同程度的致病作用,致病强度与杂草种类及粗毒素浓度有关,其中车前、马齿苋、马唐、反枝苋和灰菜5种杂草受害最重,经较低浓度(0.036mg/mL)毒素处理后1d即开始出现褐色斑点,第3天病斑面积达到最大(50%以上);该粗毒素(0.036mg/mL)对车前等5种杂草种子萌发、幼根和幼芽伸长也均有显著的抑制作用,且随毒素浓度升高抑制作用增强,抑制率均在53%以上,但对小麦和大豆种子萌发及根芽伸长均无明显的抑制作用;粗毒素经紫外线照射后,对车前和蒲公英的除草活性在自然光照下比黑暗下明显增强。这些结果揭示石楠拟盘多毛孢粗毒素有一定的除草潜力。

Phytocidal activity of crude toxin produced by Pestalotiopsis photiniae

Pestalotiopsis photiniae is the dominant pathogen of strawberry root rot,and causes disease by its toxin.In order to understand the effect of its toxin on several common weeds,the pathogenicity of crude toxin on these weeds were investigated using detached leaf and root-bud elongation methods.The results showed that P.photiniae crude toxin had evident pathogenicities on all tested 13 species of weeds.The damage of toxin on plantain,purslane,hairy finger,redroot amaranth,and siberian cocklebur was significantly stronger than that on other weeds.The necrotic spots on these weeds leaves appeared at the first day and spot areas reached the maximum(more than 50%) at the third day after treatment with 0.036 mg/mL toxin.In addition,crude toxin strongly inhibited seed germination,root and bud elongation of above mentioned weeds,and inhibition rates were more than 53%,but did not inhibit those of wheat and soybean.Pathogenicities of crude toxin after ultraviolet radiation on plantain and dandelion leaves were enhanced under natural light.These results reveal that P.photiniae toxin has a potential in control common weeds in future.