基于DNA条形码的食用菌与其易混有毒真菌的鉴定

Identification of edible fungi and their easily mixed wild toxic fungi based on DNA barcodes

中文关键词:  分子鉴定  大型真菌  DNA条形码技术

英文关键词:molecular identification  edible fungi  wild toxic fungi  DNA barcoding

中文摘要:

      目的 利用DNA条形码技术对常见可食用真菌与其易混的野生有毒真菌进行分子鉴定。方法 使用MEGA7.0软件对GenBank中获得菌类的ITS2、nrLSU及EF1-α基因序列进行分析和序列比对, 计算各分类群种内与种间的kimura 2-parameter (K2P)遗传距离、构建相邻结合法(neighbor joining, NJ)系统聚类树, 利用ITS2数据库预测各物种的ITS2二级结构。利用4Sale软件进行ITS2二级结构比对, 运用ProfDistS软件构建剖面邻接(profile neighbor joining, PNJ)进化树。结果 遗传距离结果表明各分类群存在明显的条形码间隔(barcoding gap); NJ树结果显示各物种均可独立分支, 具有良好的单系性; PNJ树同样可以区分食用菌与易混有毒真菌; 各物种的ITS2二级结构均存在明显差异。结论 ITS2、nrLSU和EF1-α可作为DNA条形码用于可食用真菌与其易混的野生有毒真菌的鉴定, 为推动真菌的分子鉴别在食品安全管理中广泛应用, 保障食品安全与公众健康提供了新的技术手段。

英文摘要:

      Objective To conduct molecular identification of common edible fungi and their easily mixed wild toxic fungi by DNA barcoding technology. Methods MEGA7.0 software was used to analyze and align the ITS2, nrLSU, and EF1-α gene sequences of fungi obtained from GenBank. The kimura 2-parameter (K2P) genetic distance within and between each taxonomic group was calculated, the neighbor joining (NJ) system cluster tree was constructed, and the secondary structure of ITS2 for each species was predicted by ITS2 database. 4Sale software was used to compare ITS2 secondary structure, and the ProfDistS software was used to construct a profile neighbor joining (PNJ) evolutionary tree. Results The genetic distance results indicated that there were significant barcoding gap in each taxonomic group; the NJ tree results showed that each species could independently branch and had good monophyletic traits; PNJ trees could also distinguished between edible fungi and easily mixed toxic fungi; there were significant differences in the secondary structure of ITS2 among different species. Conclusion ITS2, nrLSU, and EF1-α can be used as a DNA barcode for the identification of edible fungi and their easily mixed wild toxic fungi, providing a new technological means for promoting the widespread application of fungal molecular identification in food safety management and ensuring food safety and public health.