野生型金龙胆草核型和亲缘地理结构分析

Analysis on Karyotype and Phylogeographic Structure of Wild-type Conyza blinii H.Lév.

金龙胆草Conyza blinii H.Lév.为我国云贵川地区重要的中药材,具有良好的消炎,止咳,平喘的功效。为了探究野生金龙胆草居群间的差异及其产生原因,本试验采集了9个不同地区的野生金龙胆草样本,对其进行苦蒿素含量测定、土壤无机元素含量测定、核型分析、叶绿体基因组以及亲缘地理结构分析。结果显示:在这9个居群中,攀枝花地区的野生金龙胆草次生代谢产物苦蒿素含量最高(4.8 mg/g),且该地区土壤Fe元素含量最高(5.52%)。核型分析显示金龙胆草为二倍体,染色体核型公式2n=2x=20=18m+2st。叶绿体基因组的系统进化分析表明,金龙胆草与匙叶紫菀(Aster spathulifolius Maxim.)亲缘关系较近。基于金龙胆草cpDNA的亲缘地理分析结果显示,Hap1为祖先型且金龙胆草经历过种群扩张事件,AMOVA分析显示6.2%的变异来自居群间,93.8%的变异来自居群内,居群间分化程度中等。综上,金龙胆草居群间并无显著的染色体变异,所以种群内部变异和土壤环境因素可能是金龙胆草居群间产生不同程度的苦蒿素含量差异的原因,本研究为金龙胆草野生资源的开发和利用提供理论基础。

In order to explore the diversity among wild C.blinii H.Lév.populations,nine samples collected from different regions were analyzed for their blinin content,soil inorganic element content,karyotype analysis,chloroplast genome and genetic geographic structure were analyzed.The results showed that blinin content,the secondary metabolite of wild C.blinii H.Lév in Panzhihua area,was the highest(4.8 mg/g),and the Fe content in the soil was the highest(5.52%).C.blinii H.Lév.tenuifolia was identified as diploid species(2n=2x=20=18m+2st),and no significant difference in karyotype between populations was detected.Phylogenetic analysis of chloroplast genome showed a close relation with Aster spathulifolius Maxim.The cpDNA phylogeographic analysis revealed that Hap1 was an ancestral type and had experienced population expansion events.AMOVA analysis showed that 6.2%variation came from among populations,93.8%from came from within populations,and the degree of differentiation between populations was moderate.In conclusion,there is no significant chromosomal variation among wild C.blinii H.Lév populations,the variation within the populations and soil environmental factors may be the reasons for the different of blinin content.This study provides a theoretical basis for the development and utilization of the wild resources of C.blinii H.Lév..