KMS XINJIANG INSTITUTE OF ECOLOGY AND GEOGRAPHY，CAS
| 中国西北干旱区革苞菊属、脓疮草属植物谱系地理学研究 | |
| Alternative Title | The Phylogeography study of Tugarinovia Iljin and Panzeria Moench in arid areas of northwest China |
| 赵艳芬 | |
| Subtype | 博士 |
| Thesis Advisor | 张明理 ; 潘伯荣 |
| 2019-06-30 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 北京 |
| Degree Discipline | 理学博士 |
| Keyword | 中国西北干旱区 谱系地理学 地理障碍 革苞菊属 脓疮草属 Arid land in northwest China Phylogeograpy Geographic isolation Tugarinovia Iljin Panzeria |
| Abstract | 第四纪气候波动对西北干旱区许多植物的种内分化和居群遗传结构有着显著的影响。 为了揭示第四纪气候变化以及沙漠形成、 演化对中国西北干旱区草本植物的影响， 本文选取了我国荒漠种子植物区系成分， 且在属内物种分类上存在争议的草本植物革苞菊属（Tugarinovia Iljin） 和脓疮草属（Panzeria Moench） 植物作为研究对象。 其中， 革苞菊属隶属于菊科（Asteraceae）， 是一个单种属，包含革苞菊（T. mongolica Iljin）及变种卵叶革苞菊（T. mongolica var ovatifolia Linget Y. C. Ma）。革苞菊已被列入《中国植物红皮书》和国家重点保护的野生植物，也是蒙古高原特有成分。 革苞菊和变种卵叶革苞菊分别分布于内蒙古北部和南部，呈狭域分布，并且在有限的分布区内，居群个体数量很少。 脓疮草属是唇形科（Labiatae）的一个小属，该属植物在西北干旱区分布较广泛，主要分布在蒙古高原的草原区和草原化荒漠区，是蒙古高原的近特有属。在本研究中， 革苞菊属植物运用两个叶绿体基因片段（psbA-trnH 和psbK-psbI），脓疮草属植物运用两个叶绿体片段（trnH-psbA 和 rpoB-trnC） 和一个核基因片段（ITS1-ITS4） 分别对这两个属的遗传多样性和谱系格局成因进行探讨和比较， 主要结果如下：1、对涵盖国内绝大多数分布点的革苞菊属的 16个居群 219个样本进行测序，结果共识别了 17 个（H1-H17） 单倍型。 SAMOVA 分析将这 16 个居群划分为两个明显的谱系分支： 北部组（革苞菊）和南部组（变种卵叶革苞菊），且两个组之间没有共享单倍型。 谱系分化也得到了分子方差分析（AMOVA） 和 BEAST分析的支持。 AMOVA 分析结果表明 52.86%的遗传变异发生在两个地理组之间。革苞菊属植物总的遗传多样性较高（HT = 0.947），居群内遗传多样性较低（HS =0.185）， 表现出很高的遗传分化值（GST = 0.805）；南部组的居群具有更高的遗传漂变（FST = 1， GST = 1） 和近亲繁殖（HT = 1， HS = 0） 负荷。 通过对脓疮草属植物 27 个居群的 269 个个体进行测序， 共得到 7 个叶绿体单倍型和 32 个核基因单倍型。 该属植物具有高水平的遗传多样性（cpDNA： Hcp = 0.6691， HT = 0.673；nrDNA： Hnr = 0.5668， HT = 0.577）。在叶绿体序列中，该属居群间的遗传分化值较高（GST = 0.950）。 分子方差分析（AMOVA）结果显示脓疮草属植物 89.87%的遗传分化发生在三个地理组间（北部组， 中部组和东部组）。 中部组位于贺兰山周边， 具有高水平的遗传多样性（Hcp = 0.6673； HT = 0.753），东部组可能经历了奠基者效应导致物种遗传多样性很低（Hcp = 0.1364； HT = 0.137）。在核基因中，居群间的遗传分化值较低（GST = 0.348），且仅有 8.7%的遗传变异发生在三个地理组之间。2、 根据 BEAST 分析结果， 革苞菊属两个地理组间的分化可以追溯到早更新世（2.4976 Mya）， 早更新世时期的气候波动很可能是导致革苞菊属异域分歧的原因。同时，伴随着沙漠的形成， 它作为地理障碍进一步阻碍了两个地理组间的基因交流，加剧了北部组和南部组之间的分化。 脓疮草属植物 BEAST 分析结果显示， 七个叶绿体单倍型之间的分化发生在更新世早期（1.6053 Mya） 到更新世晚期（0.0857 Mya）， 这与中国西北地区的干旱化和沙漠形成、 扩张的时间相一致。干旱化和沙漠扩张导致了物种多样化和生境片段化。此外，我们推测，沙漠和贺兰山可能作为有效的地理障碍也促进了脓疮草属种内的分歧。3、 以上研究结果表明， 革苞菊和变种卵叶革苞菊之间的遗传分化与赵一之提出的形态分类学观点一致， 建议将分布在南部组的变种卵叶革苞菊作为一个独立种处理。 由于革苞菊在川井苏木、乌力吉和银根的居群拥有较高水平的遗传多样性， 且已被列入国家Ⅰ级重点保护的野生植物， 尚未建立自然保护区，分布区当地除了关注该物种的保护，还考虑植物遗传多样性的保护，因此，需要对这几个特殊的居群设立自然保护小区。南部组的卵叶革苞菊居群则表现出更高的遗传漂变和近亲繁殖负荷，需要对每一个居群进行单独保护。 因此，根据我们的研究结果提出如下建议： 革苞菊属植物的保护应该通过就地保护结合迁地保护的方式来增加物种的有效居群数量和遗传多样性水平。脓疮草属的遗传分化特点支持赵一之对该属的分类处理：阿拉善脓疮草（P. alaschanica） 和甘肃脓疮草（P.kansuensis） 不应该作为 2 个独立的物种，应该归并在脓疮草复合体（P. lanata）中。综上所述，分布在西北干旱区的草本植物革苞菊属和脓疮草属主要受更新世气候波动影响，由于更新世气候变化导致西北地区气候变干、变冷，引起沙漠形成和扩张。沙漠作为地理障碍，导致近缘物种间基因交流受阻，引起总的遗传多样性较高，居群内平均遗传多样性较低，伴随着高的遗传分化值，最终导致物种的分化和形成。以上结果类似于西北干旱区分布的其他植物的遗传多样性和谱系格局，即生境相似的植物表现出相同的遗传结构特征和谱系格局。 |
| Other Abstract | Quaternary climate fluctuations have significant effects on the intraspecificdifferentiation and population genetic structure of many plants in arid northwestChina. In order to reveal the impact of Quaternary climate change and desertformation and evolution on the herbaceous plants in the arid northwest China, thepaper selected floristic components of desert seed plants in China and thecontroversial herbaceous in the classification of Tugarinovia Iljin and PanzeriaMoench were studied. Among them, Tugarinovia belongs to Asteraceae family, and isa monotypic genus including T. mongolica Iljin and one additional variety, T.mongolica var ovatifolia Ling et Y. C. Ma. T. mongolica has been listed in the “ChinaPlant Red Book” and the national key protected wild plants. It is also endemiccomponent of the Mongolian Plateau. The two species were distributed in the northand south of Inner Mongolia, respectively. The species has a limited geographicalrange and declining populations. Panzeria is a small genus of Labiatae family. It ismainly distributed in the grassland and grassland desert areas of the MongolianPlateau. It is a near endemic genus of Mongolian Plateau.In this study, two chloroplast gene fragments (psbA-trnH and psbK-psbI) for theTugarinovia and two chloroplast fragments (trnH-psbA and rpoB-trnC), one nucleargene fragment (ITS1-ITS4) for Panzeria were used to explore and compare thegenetic diversity and phylogeographic patterns of these two genera, respectively. Themain results are as follows:(1) A total of 219 samples from 16 populations of Tugarinovia covering most ofthe distribution sites were sequenced in China and 17 (H1-H17) haplotypes wereidentified. The SAMOVA analysis divided the 16 populations into two distinctlineages: the northern (T. mongolica) and southern groups (T. mongolica var.ovatifolia), and no haplotypes were shared between the two groups. The lineagedifferentiation was also supported by AMOVA and BEAST analyses. AMOVA analysis showed that 52.86% of genetic variation occurred between two geographicalgroups. The total genetic diversity was higher (HT = 0.947), and genetic diversitywithin populations was lower (HS = 0.185), showing a high genetic differentiationvalue (GST = 0.805). The southern group showed a higher genetic drift (FST = 1, GST =1), and the inbreeding load (HT = 1, HS = 0). Seven chloroplast haplotypes andthirty-two nuclear haplotypes were obtained by sequencing 269 individuals from 27populations of Panzeria. The result revealed high levels of genetic diversity (cpDNA:Hcp = 0.6691, HT = 0.673; nrDNA: Hnr = 0.5668, HT = 0.577) and high level ofgenetic differentiation (GST = 0.950) among populations in the cpDNA sequences.AMOVA results showed that 89.87% of the genetic variation occurred among threegeographic groups (northern, central, and eastern group). The central group is locatedaround Helan Mountains and has a high level of genetic diversity (Hcp = 0.6673; HT =0.753). The eastern group may have experienced a founder effect leading to lowgenetic diversity (Hcp = 0.1364; HT = 0.137). In the nuclear genes, the geneticdifferentiation value among populations was low (GST = 0.348), and only 8.7% ofgenetic variation occurred among the three geographic groups.(2) According to BEAST analysis, the differentiation between the twogeographic groups of Tugarinovia can be traced back to the early Pleistocene epoch(2.4976 Mya), when climate fluctuations most likely resulted in the allopatricdivergence of Tugarinovia. At the same time, with the formation of desert, as ageographic barrier, it further blocked gene flow between the two geographic groups,and also enhanced the differentiation of the northern and southern groups. TheBEAST analysis of Panzeria showed that the divergence between the seven cpDNAhaplotypes occurred in the early Pleistocene (1.6053 Mya) to the late Pleistocene(0.0857 Mya), coincides with aridification and expansion of the desert acrossnorthwest China that resulted in species diversification and habitat fragmentation. Inaddition, we speculate that the deserts and the Helan Mountains may act as effectivegeographic barriers to promote the intraspecific diversity of Panzeria.(3) The above results indicate that the genetic differentiation between T.mongolica and T. mongolica var. ovatifolia are consistent with the morphologicaltaxonomy proposed by Yizhi Zhao. This paper proposes to treat T. mongolica varovatifolia distributed in the southern group as an independent species. In the northerngroup, the populations Chuanjinsumu, Wuliji and Yingen displayed the higher level ofgenetic diversity, and has been included in the national level I protected wild plants,no nature reserves have been established. In addition to paying attention to theprotection of this species, the protection of plant genetic diversity should also beconsidered. Therefore, it is necessary to establish a nature reserve for thesepopulations. The southern group showed a higher genetic drift and the inbreeding loadrequired protection for each population. Based on our results propose that theprotection of Tugarinovia should be implemented through in situ and ex situconservation practices to increase the effective population size and genetic diversity.The genetic differentiation characteristics of Panzeria support Yizhi Zhao's taxonomictreatment of this genus. P. alaschanica and P. kansuensis should not be regarded astwo independent species, but should be included in the P. lanata.In summary, the herbaceous plants Tugarinovia and Panzeria distributed in thearid northwest China were most affected by climate fluctuations of Pleistocene. Dueto the Pleistocene climate change, the northwest China became dry and cold, andcaused desert formation and expansion. Desert as a geographic barrier, resulted in theblockage of gene flow among closely related species, and csused high total geneticdiversity, lower average genetic diversity within populations, accompanied by highergenetic differentiation value, which ultimately leads to species differentiation andformation. The above results are similar to the genetic diversity and phylogeographicpatterns of other plants distributed in arid northwest China, that is, plants with similarhabitats show the same genetic structure and phylogeographic patterns. |
| Subject Area | 植物学 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.xjlas.org/handle/365004/15377 |
| Collection | 中国科学院新疆生态与地理研究所 研究系统 |
| Affiliation | 中国科学院新疆生态与地理研究所 |
| First Author Affilication | 中国科学院新疆生态与地理研究所 |
| Recommended Citation GB/T 7714 | 赵艳芬. 中国西北干旱区革苞菊属、脓疮草属植物谱系地理学研究[D]. 北京. 中国科学院大学,2019. |
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