白术两种主要土传病害的分离、鉴定及杀菌剂的室内活性筛选

Isolation and identification of two main soil-borne pathogens on Atractylodes macrocephala and screening of fungicides in vitro

立枯病和白绢病是白术生产种植中的两种主要土传病害,在苗期和生长期都有发生,危害严重。本研究从浙江省磐安县采集具有典型病症的白术植株,对病原进行了分离、纯化和致病性测定。综合形态学特征及rDNA-ITS序列分析表明,白术上的病害是由立枯丝核菌Rhizoctonia solani Kühn引起的立枯病和由齐整小核菌Sclerotium rolfsii Sacc.引起的白绢病。室内毒力测定结果表明,10种供试杀菌剂对立枯病菌的毒力从大到小为:噻呋酰胺>咯菌腈>戊唑醇>四氟醚唑>吡唑醚菌酯>丙硫菌唑>嘧菌酯>啶酰菌胺>苯醚甲环唑>咪鲜胺;对白绢病菌的室内毒力从大到小为:吡唑醚菌酯>噻呋酰胺>嘧菌酯>戊唑醇>咯菌腈>苯醚甲环唑>丙硫菌唑>啶酰菌胺>四氟醚唑>咪鲜胺,其中噻呋酰胺对两种病菌都具有很高的活性,EC_(50)分别为0.06和0.03mg/L,可用于两种病害的防治。

The sheath blight and southern blight are two major soil-borne diseases in the cultivation of Atractylodes macrocephala,which occur severely during seedling and growing periods.In this study,we collected Atractylodes plants with typical symptoms from Pan'an County,Zhejiang Province,and determined the pathogens through isolation,purification and pathogenicity tests.Morphology characteristics and rDNA-ITS sequence analysis indicated that the pathogens were Rhizoctonia solani for sheath blight disease and Sclerotium rolfsii for southern blight disease,respectively.Indoor toxicity tests demonstrated that the bioactivity against R.solani were:thifluzamide>fludioxonil>tebuconazole>tetraconazole> pyraclostrobin > prothioconazole > azoxystrobin > boscalid >difenoconazole> prochloraz,and the bioactivity against S.rolfsii were:pyraclostrobin >thifluzamide> azoxystrobin >tebuconazole> fludioxonil> difenoconazole> prothioconazole> boscalid>tetraconazole> prochloraz.Among them,thifluzamide was most effective to both pathogens,with EC50 values of 0.06 and0.03 mg/L,respectively.