贵州花椒褐斑病病原鉴定及防治药剂筛选

Identification and screening fungicides of the pathogen of Zanthoxylum bungeanum brown spot

近年来,贵州花椒产区发生一种新的褐斑病害。为明确引起花椒褐斑病的病原,本研究从惠水县断杉镇花椒基地采集花椒褐斑病样本,采用组织分离法和致病性测定获得花椒褐斑病菌。通过对花椒褐斑病菌的形态学观察及ITS、RPB2和LSU序列分析,将花椒褐斑病菌鉴定为细极链格孢(Alternaria tenuissima)。杀菌剂室内抑菌活性测定表明,选用的10种杀菌剂对A.tenuissima的生长均表现出一定的抑制作用,其中以25%吡唑醚菌酯悬浮剂、30%肟菌·戊唑醇悬浮剂和60%苯醚甲环唑水分散粒剂对该病原菌生长的抑制作用较强,EC50值分别为0.0449、0.1295和0.6769μg·mL^(-1)。本研究结果为花椒褐斑病的有效防控提供了参考。

In recent years,a new important disease on Zanthoxylum bungeanum was found in Guizhou Province,and named as the brown spot of Z.bungeanum.To identify the pathogen,the typical disease samples were collected from producing areas in Duanshan Town,Huishui County,Guizhou Province for isolation.The pathogen was obtained by tissue isolation and pathogenicity test.Based on the morphological observation and sequence analysis of internal transcribed spacer(ITS),RNA polymerase II(RPB2)and large ribosomal subunit(LSU),Alternaria tenuissima was identified as the pathogen causing Z.bungeanum brown spot.The experiments for the antifungal activity screening in vitro showed that all the ten fungicides selected in this study showed certain inhibitory effects on the colony growth of A.tenuissima,where 25%Pyraclostrobin SC,30%Oxime·tebuconazole SC,and 60%Difenoconazole WG exhibited relatively higher inhibitory effects with the EC50 values of 0.0449,0.1295 and 0.6769μg·mL^(-1),respectively.The above results would provide a helpful guidance for effectively controlling Z.bungeanum brown spot.