基于psbA-trnH基因和18S rDNA的薯蓣属植物系统发育分析

发布时间：2018-05-22 18:19

本文选题：薯蓣属 + 亲缘关系　；参考：《内蒙古农业大学》2017年硕士论文

【摘要】：薯蓣(Dioscorea)是薯蓣属(Dioscoreaa)薯蓣科(Dioscoreaceae)薯蓣目(Dioscoreales)植物。薯蓣科现存大约有650多个种,其系统发育关系还不能确定。薯蓣属植物是多年生且药食兼用的草本植物,其中山药是薯蓣属植物中部分可食用块茎种类的通用名称。此些种类因其块茎淀粉产量高在非洲、亚洲、拉丁美洲、加勒比海和大洋洲广泛种植。薯蓣属植物中栽培较多的种为大薯(alaaa)和薯蓣(Dioscorea),因在长期的进化过程中薯蓣属种类繁多,在栽培和相互引种过程中种类及品种混杂,近缘种难以用传统的形态分类进行区分,市场中存在同名异物、同物异名的现象较为严重,对薯蓣属种质资源的保护和区分尤为重要。本文通过分析山药63个不同样品的psbA-trnH基因片段序列和51个不同薯蓣属植物样品的18SrRNA基因片段序列的亲缘关系和系统关系,结果表明:1.对其61种薯蓣属植物的Q型聚类分析结果表明,各样品间欧式距离差异大,能准确辨别种间关系,具有良好的种质资源辨别作用,当阈值为7.41时,61个薯蓣属植物样品总体分为两大类。2.对63个山药的psbA-trnH基因片段序列进行分析结果显示,所有品种的基因片段序列长度在331bp～418bp之间,序列亲缘关系在100%～50%之间,遗传距离在0.518～0.00之间。其中核苷酸变异位点264个,简约信息位点205个,保守位点178个。核苷酸序列具有明显的种间差异,能够明确区分种间关系。3.通过对51个薯蓣属植物样品18SrRNA基因片段分析,结果显示该基因片段序列长度在1765bp～1652bp之间,其亲缘关系在49%～100%之间。遗传距离在0.000～0.508 之间。4.对薯蓣属psbA-trmH基因片段序列和18S rRNA基因片段序列的聚类分析结合形态指标的聚类分析,可以说明海南山药、洋溪山药、广东大薯、明淮3号山药之间亲缘关系最近,遗传距离为0。陆良山药与曲靖山药与大薯类亲缘关系较近,遗传距离为0,说明此些品系很可能是与田薯类或与田薯近缘种。5.在聚类中表明,河南铁棍山药(2013)与其他河南铁棍山药未能聚在一类中,推测它可能是河南铁棍山药的混淆种。6.基于18SrRNA基因的聚类结果,云南丽江热河野山药中独聚在一支,与普通山药和大薯种之间的亲缘关系较远,推测可能属于其他种或品系。
[Abstract]:Dioscorea (Dioscorea) is a plant of Dioscorea (Dioscorea). There are more than 650 species in the family Dioscorea, whose phylogenetic relationship is uncertain. Dioscorea is a perennial herbaceous plant with both medicine and food, in which yam is the common name of some edible tuber species in Dioscorea. These species are widely cultivated in Africa, Asia, Latin America, the Caribbean and Oceania because of their high tuber starch production. The most cultivated species in the genus Dioscorea are Alaaaa) and Dioscorea zingiberensis. Because there are many species of Dioscorea in the long evolution process, the species and varieties are mixed in the process of cultivation and mutual introduction, so it is difficult to distinguish the relative species by traditional morphological classification. There are homonyms and synonyms in the market, so it is very important to protect and distinguish the germplasm resources of Dioscorea. The phylogenetic relationship and phylogenetic relationship of psbA-trnH gene fragments in 63 different samples of Dioscorea and 51 samples of Dioscorea were analyzed. The results of Q cluster analysis of 61 species of Dioscorea showed that there were great differences in the European distance among the samples, which could accurately distinguish the interspecific relationships and had a good discriminating effect on germplasm resources. When the threshold value is 7.41, 61 samples of Dioscorea can be divided into two categories. The results of the analysis of 63 psbA-trnH gene fragments of Chinese yam showed that the length of the gene fragments was between 331bp~418bp, the genetic relationship was between 100% and 50%, and the genetic distance was between 0.5180.00 and 0.5180.00. Nucleotide mutation sites were 264, parsimonious information sites were 205, and conserved sites were 178. The nucleotide sequence has obvious interspecific differences, and can clearly distinguish between species. 3. The 18SrRNA gene fragments of 51 samples of Dioscorea were analyzed. The results showed that the length of the 18SrRNA gene fragment was between 1765bp~1652bp and the genetic relationship was between 49% and 100%. The genetic distance was between 0.000 and 0.508. The cluster analysis of psbA-trmH gene fragment sequence and 18s rRNA gene fragment sequence of Dioscorea combined with the cluster analysis of morphological indexes can show that the genetic relationship between Dioscorea yam, Yangxi yam, Guangdong Big Potato and Minghuai No.3 is the closest, and the genetic distance is 0. The genetic distance between Luliang yam and Qujing yam is close, the genetic distance is 0, which indicates that these strains are probably related to potato or tuber. 5. In the cluster, it is shown that Henan Ironbar yam (2013) and other Henan Ironbar yam can not be clustered in the same group, suggesting that it may be a confounding species of Henan Ironbar yam. Based on the clustering results of 18SrRNA gene, there is only one branch of Yehe yam in Lijiang, Yunnan, which is far related to common Chinese yam and large potato species, so it may belong to other species or strains.
【学位授予单位】：内蒙古农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S632.1

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