贵州烟草棒孢霉叶斑病生防菌鉴定及防治药剂筛选

为有效防治烟草棒孢霉叶斑病，采用Biolog全自动微生物鉴定系统鉴定了本实验室前期工作中筛选得到的生防菌株YC2140，进一步对其进行了16S rRNA和gyr B序列分子鉴定，并选取生产上常用的5种杀菌剂和YC2140菌株进行了盆栽和田间防效试验。结果显示，经Biolog鉴定和分子鉴定，YC2140菌株为荧光假单胞菌Pseudomonas fluorescens。盆栽试验结果表明，在药剂推荐施用剂量(449.78 mL/hm²或449.78 g/hm²)下，对烟草棒孢霉叶斑病的防治效果由高到低依次为500 g/L氟啶胺悬浮剂(防治效果78.77%)、450 g/L咪鲜胺水乳剂(77.85%)、430 g/L戊唑醇悬浮剂(67.12%)、1×10⁸ cfu/mL YC2140发酵液(61.64%)和50%啶酰菌胺水分散粒剂(46.12%)。相同施药剂量下的田间试验结果表明，防治效果由高到低依次为450 g/L咪鲜胺水乳剂(43.33%)、500 g/L氟啶胺悬浮剂(40.97%)、430 g/L戊唑醇悬浮剂(27.94%...

Identification of biocontrol strain and screening of fungicides against Corynespora leaf spot on tobacco in Guizhou Province

In order to effectively control the tobacco Corynespora leaf spot, the biocontrol strain YC2140 screened in the previous work of our laboratory was identified by Biolog automatic microbial identification systemlog automatic microbial identification system 16S rRNA and gyrB sequence molecular identification. Five fungicides commonly used in production and YC2140 were selected for pot and field control experiments. Results showed that the YC2140 strain was identified as Pseudomonas fluorescens by molecular method and Biolog identification system. The pot experiment results showed that under the recommended dosage (449.78 mL/hm2 or 449.78 g/hm2), the control efficacy on Corynespora leaf spot from high to low was fluazinam 500 g/L SC (the control efficacy was 78.77%), prochloraz 450 g/L EW (77.85%), tebuconazole 430 g/L SC (67.12%), 1 × 108 cfu/mL YC2140 fermentation broth (61.64%) and boscalid 50% WG (46.12%). The field trial results under the same dosage showed that the control efficacy from high to low was prochloraz 450 g/L EW (43.33%), fluazinam 500 g/L SC (40.97%), tebuconazole 430 g/L SC (27.94%), 1 × 108 cfu/mL YC2140 fermentation broth (26.15%), 70% mancozeb WP (dosage 2998.50 g/hm2, control efficacy 21.99%). The results of this study can provide reference for the screening of fungicides for the control of tobacco Corynespora leaf spot disease.