植物源提取物对三七根腐病病原菌的抑菌效应及对三七的化感作用

Antifungal effects of plant extracts on root-rot pathogens and allelopathy on Panax notoginseng

筛选出适宜的植物源,以期为三七根腐病的绿色防控及生态种植提供新的可行的途径。以三七根腐病病原菌Fusarium oxysporum、Fusarium solani、Cylindrocarpon destructans和Alternaria panax为靶标,采用平板对峙法分析多种植物源提取液对病原菌的抑菌效果、抑菌时效和毒力值,并通过计算化感响应指数(RI)探明其对三七种子萌发、出苗及生长的化感作用。结果表明:紫茎泽兰提取液对F.solani和C.destructans抑菌率最高(分别为64%和90%),且抑制时效最长;野艾蒿提取液对F.oxysporum和C.destructans抑菌效果显著,并使A.panax菌落7 d内接近零增长;黄花蒿、土荆芥、大蓟和大狼毒提取液对4种病原菌的抑菌率均达50%以上;紫茎泽兰、黄花蒿和野艾蒿植物源的毒力效应均高于对照多菌灵(P<0.05);植物源提取物对三七种子萌发表现出"低促高抑"的浓度效应,黄花蒿、紫茎泽兰和野艾蒿在低浓度时(2.5 mg·mL^(-1))化感促进作用显著;植物源提取物对三七的出苗率和株高存在促进效应,黄花蒿和大蓟最显著。紫茎泽兰、黄花蒿和野艾蒿提取物在三七根腐病绿色防控中具有应用潜力。

To select suitable plant sources for the green control of Panax notoginseng root rot and provide a new feasible way for ecological planting,we used Fusarium oxysporum,Fusarium solani,Cylindrocarpon destructans,and Alternaria panax as the targeted root-rot pathogenic fungi of Panax notoginseng.The antifungal effect,antifungal time,and virulence value of various plantderived extracts against pathogenic fungi were analyzed by plate confrontation method.The allelopathic response index(RI)was calculated to investigate the allelopathic effects on the germination and emergence of P.notoginseng seeds and seedling growth.The extract of Eupatorium coelestinum had the highest antifungal rate against F.oxysporum and C.destructans,which were 64%and 90%,respectively,while the inhibition time was the longest.The extract of Artemisia lavandulaefolia had a significant inhibitory effect on F.oxysporum and C.destructans,and caused A.panax to fall near zero growth within seven days.The antifungal rates of Artemisia annua,Chenopodium ambrosioides,Cirsium japonicum,and Euphorbia jolkinii extracts for the four pathogens were above 50%.The toxic effects of E.coelestinum,A.annua,and A.lavandulaefolia were all higher than that of carbendazim(P<0.05).Plant-derived extracts showed a"low boosting-high inhibition"concentration effect on seed germination of Panax notoginseng,with significantly promoting effect of A.annua,E.coelestinum and A.lavandulaefolia at low concentration(2.5 mg·mL^(-1)).Plant-derived extracts had positive on seedling yield and plant height,with A.annua and C.japonicum being the most significant.Therefore,extracts of E.coelestinum,A.annua,and A.lavandulaefolia have the potential of being applied in green control of Panax notoginseng root rot.