广西三七灰霉病流行规律及药剂筛选

Occurrence of Panax notoginseng Grey Mould and Selection of Funficides in Guangxi

对广西三七灰霉病的典型病斑进行分离培养、致病性检测,通过形态学观察并结合r DNA-ITS序列分析鉴定病原菌;通过室内及田间试验研究了温湿度对菌丝生长、孢子萌发的影响,以及病害的病程和病斑显症率,并对不同立地条件、不同生长年限三七灰霉病的发生规律进行调查;最后采用菌丝生长速率法研究了15种杀菌剂对病原菌的抑制作用。结果表明,三七灰霉病病原菌为灰葡萄孢菌(Botrytis cinerea);菌丝生长、孢子形成及萌发的最适温度为20℃,孢子萌发需要高湿度,低于100%湿度不萌发;不同季节、不同生长年限三七的病程为5~13 d,病斑在田间的持续显症期为6 d;三七灰霉病在三七生长期都能发生,10~11月份为发生高峰期,其中不同立地条件下的发病严重度顺序为旱地>坡地>林下,不同生长年限下的顺序为3年生三七>2年生三七>1年生三七;咯菌腈、嘧菌环胺与嘧菌酯、氟硅唑对病原菌的菌丝生长抑制率达100%。

In the study, the pathogen of Panax notoginseng Grey was isolated and cultured. Moreover, single spore isolates,morphological observation, pathogenicity test, and combined with molecular biology methods were used to identify the pathogen. Mycelium growth, spore germination, the course of the disease and the lesion appearance rate were studied in the laboratory and field; The disease occurrence was studied in the P. notoginseng gardens of different site conditions and different growing years. The inhibitory rates of 15 fungicides were tested using the mycelium growth rate method. The results indicaded that the pathogen was Botrytis cinerea. The proper temperature for mycelium growth, spore formation and germination was 20 ℃; Conidia did not germinate in the condition of relative humidity bellow 100%; The development of the disease was different for P. notoginseng of different age and different season,and the period of symptomatic appearance of the disease was about 6 d; The disease occurred during the whole growth period of the host plants, and the disease peak was from October to November; The disease severity was drylandslopeunder forest, and that for growing ages was three yearstwo yearsone year; Four kinds of fungicides including fludioxonil, cyprodinil, azoxystrobin, and flusilazole showed high inhibitory rates of 100% on B. cinerea.