7种杀菌剂和5种植物抗病激活剂对油茶炭疽病病菌活性研究

Activities of 7 Fungicides and 5 Plant Disase Elicitors on the Pathogen of Camellia oleifera

胶孢炭疽菌引起的油茶炭疽病是油茶的主要病害之一,试验通过室内毒力测定及活体测定,分别筛选出防治油茶炭疽病的高效杀菌剂和植物抗病激活剂。采用菌丝抑制法测定杀菌剂及植物抗病激活剂对胶孢炭疽菌的毒力;采用离体叶片法,通过病斑减小率评价植物抗病激活剂对油茶炭疽病的诱抗效果。供试7种杀菌剂中以咪鲜胺抑菌活性最强,EC_(50)为0.129 mg/L;嘧菌酯抑菌活性最低,EC_(50)为52.110 mg/L;植物抗病激活剂对菌丝生长无直接抑制作用,但在2年生的油茶苗上喷施后,对病斑在叶片上的扩展均有一定抑制作用,以水杨酸100 mg/L剂量处理的叶片诱导抗病性最佳,诱抗效果为50.13%,芸苔素内酯、茉莉酸甲酯,井岗霉素,苯并噻二唑处理组的最大诱导防病效果依次为36.82%、26.93%、19.67%、17.73%。该试验结果为杀菌剂和植物抗病激活剂的复配制剂提供参考依据,为油茶炭疽病的防治提供新思路。

Camellia anthracnose caused by Colletotrichum gloeosporioides is one of the main diseases of Camellia oleifera.Through indoor virulence test,a fungicide and a plant disease-resistant activator that could effectively control camellia anthracnose were screened out.The virulence of fungicides and plant disease resistance activators to C.gloeosporioides was measured by the mycelial inhibition method;The in vitro leaf method was used to evaluate the induction of plant disease resistance activators on camellia anthracnose by the reduction rate of disease spots anti-defense effect.Among the seven fungicides evaluated,prochloraz had the strongest antibacterial activity,with an EC_(50) value of 0.129 mg/L;azoxystrobin had the lowest antibacterial activity,with an EC_(50) value of 52.110 mg/L;the plant disease-resistant activator had the greatest effect on mycelium.There was no direct inhibitory effect on mycelial growth.However,after spraying on two-year-old C.oleifera seedlings,it had a certain inhibitory effect on the spread of diseased spots on the leaves.Treatment of the leaves with salicylic acid with 100 mg/L dose induced the best disease resistance.The disease prevention effect was 50.13%,and the maximum induced disease prevention effects of the brassinolide,methyl jasmonate,Jinggangmycin,and benzothiadiazole treatment groups were 36.82%,26.93%,19.67%,and 17.73%,respectively.The results of this experiment provide a reference for the compound preparation of disease activator and new ideas for the prevention and treatment of C.anthracnose.