黄帚橐吾提取物对保护地辣椒4种病原真菌的抑制活性及其病害防效

Inhibition activities and control efficiency of extracts from Ligularia virgaurea against 4 fungal diseases of greenhouse peppers

针对保护地辣椒多发、危害严重、防治困难的4种真菌病害,开发高效安全的生物农药新资源。通过菌丝生长速率法、孢子萌发法、微量稀释法、种子萌发和温室盆栽防效等试验,研究了黄帚橐吾有机溶剂提取物对保护地辣椒4种病原真菌的抑制活性及其所引发病害的防控效果以及对被保护植物的安全性。结果表明,黄帚橐吾有机溶剂提取物对灰葡萄孢(Botrytis cinerea)、尖孢镰刀菌(Fusarium oxysporum)、茄病镰刀菌(Fusarium solani)和辣椒疫霉(Phytophthora capsici)均有显著的抑制活性,抑制活性强度与其浓度呈正相关,对各病原菌菌丝生长抑制率的EC_(50)分别为11.93、51.25、19.93、13.84g·L^(-1),对其孢子萌发抑制率的EC_(50)分别为15.05、55.26、57.86、16.50g·L^(-1),最小抑菌浓度为0.83~1.75g·L^(-1),最小杀菌浓度为2.50~11.67g·L^(-1)。对4种病原真菌引发的辣椒灰霉病、枯萎病、根腐病和疫病防治效果较好,100倍稀释液的预防效果均可达75%以上,治疗效果也可达70%左右,与相应常用化学农药防效相当。但是其对辣椒种子萌发和幼苗生长有一定的抑制作用,浓度大于20.00g·L^(-1)时,种子萌发抑制率大于52.27%,幼苗株高、根长和生物量均与对照之间存在显著性差异(P<0.05)。由此证明黄帚橐吾有机溶剂提取物能有效防控保护地辣椒多发性真菌病害的危害,是一种广谱生物杀菌剂优质资源,合理应用将具有良好的开发前景。

Because of frequent occurrence of,serious damage from,and difficulty controlling 4 fungal diseases of greenhouse-grown peppers and the desirability of identifying safe and efficient biological rather than chemical technologies for control of these fungal diseases,the effects of Ligularia virgaurea extracts against 4 the fungal pathogens were investigated.The mycelium growth rate,spore germination count,microdilution,seed germination and pot experiment methods of assessing biocontrol were all used.The extracts from L.virgaurea had significant inhibitory activity on Botrytis cinerea,Fusarium oxysporum,Fusarium solani and Phytophthora capsici,and the inhibitory activity was positively correlated with concentration.The EC 50 for mycelium inhibition was,respectively,11.93,51.25,19.93,and 13.84 g·L-1,while the corresponding EC 50 values for inhibition of spore germination rate were 15.05,55.26,57.86,16.50 g·L-1,the minimum inhibitory concentration was 0.83-1.75 g·L-1,and the minimum bactericidal concentration was 2.50-11.67 g·L-1.The extracts from L.virgaurea exhibited visually obvious control efficacy on B.cinerea,F.oxysporum,F.solani and P.capsici.The preventive effect of a 100-fold diluent of the initial L.virgaurea extract was 75%of that noted above,while the control effect was up to 70%,and was similar to the effect of commonly used chemical fungicides.However,to some extent,the extracts from L.virgaurea also inhibited pepper seed germination and establishment.The inhibition of seed germination was above 52%when concentration was higher than 20.00 g·L-1,and the seedling height,root length,and biomass all showed significant reduction compared with the control(P<0.05).These results show that extracts from L.virgaurea provide broad-spectrum control against frequently-occurring fungal diseases of peppers.Prospects for development of a commercial product are good.