烟粉虱病原真菌IfB01菌株的鉴定及产孢条件优化

    Identification of whitefly pathogenic fungal strain IfB01 and optimizaton of sporulation conditions

    • 摘要:
      目的 对从烟粉虱上分离的IfB01菌株进行分类学鉴定并优化其产孢条件.
      方法 采用形态学、ITS1-5.8S- ITS2 rDNA和β-微管蛋白基因序列同源性分析方法鉴定该菌株; 比较不同培养基、培养基含水量、pH、接种量与金属元素对分生孢子产量的影响, 优化产孢条件.
      结果和结论 该菌株菌落形态、分生孢子及产孢结构与玫烟色棒孢霉Isaria fumosorosea相似, 其ITS1-5.8S-ITS2 rDNA和β-微管蛋白DNA序列与玫烟色棒孢霉和爪哇拟青霉Paecilomyces javanicus相似性高于97%, 将该菌株鉴定为玫烟色棒孢霉.培养基配方对IfB01菌株分生孢子产量影响显著, 玉米粉+麦麸混合培养基产孢量最多, 1 g培养基产孢量为6.07 × 109; 麦麸:玉米粉质量比为5:5、培养基含水量(w)为42%、接种量为6 mL菌液时, 其产孢量最高; 该菌株对pH的适应范围较广, pH 5~8时, 都有较好的产孢量; 金属元素对产孢无促进作用, 且镁、铁、钠和钙对IfB01产孢均有抑制作用.

       

      Abstract:
      Objective To identify the taxonomic of IfB01 strain, which was isolated from tobacco white-fly, and to optimize its sporulation conditions.
      Method Identification of IfB01 strain was based on morphological analysis and genetic homology analysis of ITS1-5.8S-ITS2 rDNA sequence and β-tubulin DNA genes. The effects of culture medium, moisture content, pH, amount of inoculation and metallic element on conidial yield were studied. The sporulation conditions were optimized according to the above-mentioned effects.
      Result and conclusion The morphological structure of IfB01 strain was similar to that of Isaria fumosorosea, including colony morphology, conidia and sporulation structure. Analysis of ITS1- 5.8S-ITS2 rDNA sequence and β-tubulin DNA sequences indicated that IfB01 strain shared similarity over 97% with Isaria fumosorosea and Paecilomyces javanica. The strain was identified as I. fumosorosea. Basic media and their ratios, moisture content, pH, inoculum dosages and metallic elements could generate significant influences on the conidiospore production. The sporulation quantity of each gram of corn flour and wheat bran mixed medium was 6.07 × 109, which was the most suitable medium for sporulation. When the ratio of corn flour and wheat bran was 5:5, the moisture content of the medium was 42%, the inoculation amount was 6 mL bacteria liquid of each 20 g medium, the highest spore quantity was achieved. A wide range of pH from 5 to 8 could be adapted. However, metallic elements did not seem to promote sporulation, on the contrary, magnesium, iron, sodium and calcium could inhibit conidia production.

       

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