Nosema bombycis,a crucial pathogen causing silkworm pebrin,poses a significant threat to sericulture production.This study aimed to investigate the genetic diversity within N.bombycis species,providing valuable insights for the prevention and control of silkworm pebrin in the Yunnan sericultural region.We collected infected silkworm samples from diverse rearing ar-eas in Yunnan Province,isolated and purified the Bombyx mori larvae,extracted their genomes,cloned the small subunit ribo-somal DNA(SSU rDNA)and internal transcribed spacer(ITS)sequences,and conducted comprehensive bioinformatics analy-ses.Results revealed that the SSU rDNA sequences of N.bombycis isolated in the Yunnan silkworm region exhibit over 99%ho-mology,with a genetic distance of less than 0.006.However,these isolates displayed variations in length and multiple loci,indi-cating varying degrees of polymorphism.In contrast,the rDNA-ITS sequences exhibited significant genetic differences,charac-terized by multiple base insertions or deletions,as well as single base substitutions and inversions.Utilizing the SSU rDNA and ITS sequences,we constructed a phylogenetic tree,which revealed genetic differentiation among the isolated strains of N.bomby-cis in the Yunnan sericultural region.Notably,the results indicated no direct correlation between the genetic relationships of these populations and their geographical locations.This study has significantly enriched our understanding of the intra-species ge-netic diversity of N.bombycis in the Yunnan silkworm-raising region,providing a valuable foundation for further research on silk-worm pebrin prevention and control strategies.
关键词
家蚕微孢子虫/遗传多样性/核糖体小亚基/转录间隔区
Key words
Nosema bombycis/genetic diversity/ribosomal small subunit/transcribed spacer
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万方数据