吉林省水稻鞘枯病病菌生物学特性及药剂敏感性

Pathogen Identification and Biological Characteristics of Rice Sheath Blight Caused by Nigrospora oryzae in Jilin Province and Susceptibility to Fungicides

[目的]对引起吉林省水稻鞘枯病的病原菌进行鉴定,对其生物学特性及药剂敏感性进行研究。[方法]采用组织分离,单孢纯化获得分离物。柯氏证病后结合病菌形态特征及ITS序列对病菌进行鉴定;并对病菌的生物学特性进行研究;采用生长速率法测定病菌对12种杀菌剂的敏感性。[结果]病菌鉴定为Nigrospora oryzae;病菌菌丝最适生长及产孢温度为25℃;菌丝在PCA、OA、在以甘露醇和蔗糖为碳源、胰蛋白胨为氮源的培养基上生长良好;pH值为5.0最适菌丝生长;全光照条件利于菌丝生长。病菌在PCA和OA、果糖为碳源、天冬氨酸为氮源的培养基上产孢良好;pH值为7产孢最佳,全光照条件有利于产孢。菌丝致死温度为49℃,孢子致死温度为52℃。病菌对1%申嗪霉素悬浮剂、25%咪鲜·己唑醇微乳剂、45%丙环唑水乳剂、250 g/L嘧菌酯悬浮剂、40%氟环·稻瘟灵悬浮剂、525 g/L三环·丙环唑悬浮剂、20%井·烯·三环唑可湿性粉剂的敏感性较高,EC50值小于1.0 mg/L。[结论]明确了水稻鞘枯病的病原菌种类及病菌生物学特性,筛选出7种抑菌效果较好的杀菌剂。

[Aims] This paper aims to identify the pathogen and to study biological characteristics of rice sheath blight and its susceptibility to fungicides. [Methods] The isolates were obtained by tissue isolation and single spore purification methods. Koch′ s postulation of isolates was successfully performed. According to morphological and molecular characteristics, all isolates were identified. Biological characteristics of the pathogen were studied. Mycelial growth rate was used to detect the susceptibility of the pathogen to 12 fungicides. [Results] The pathogen was identified as Nigrospora oryzae. The suitable temperature for mycelial growth and spore production was 25 ℃. The optimal media for mycelial growth were PCA and OA. Mannitol, sucrose, tryptone, pH 5, and full light were beneficial for mycelial growth. PCA, OA, fructose, pH 7 and full light were suitable conditions for sporulation. The lethal temperature of mycelial and spore were 49 and 52 ℃ respectively. The pathogen was more susceptible to phenazine-1-carboxylic acid 1% SC, prochloraz·hexaconazole 25% ME, propiconazole 5% EW, azoxystrobin 250 g/L SC,epoxiconazole·isoproth iolane 40% SC, tricyclazole·propiconazole 525 g/L SC, validamycin·diniconazole·tricyclazole20% WP than other fungicides. [Conclusions] The pathogen of rice sheath blight was identified as N. oryzae and its biological characteristics and susceptibility to fungicides were clarified, meanwhile 7 susceptible fungicides were selected.