本文選題：紅豆杉屬　切入點(diǎn)：分子譜系地理學(xué)　出處：《中國林業(yè)科學(xué)研究院》2016年博士論文　論文類型：學(xué)位論文

【摘要】：中國的紅豆杉屬(Taxus L.)植物資源豐富,分布廣泛,中國植物志(1999)中記載有三種兩變種。由于人們過度開發(fā)利用,已經(jīng)處于瀕危狀態(tài)。因此了解紅豆杉屬植物天然群體的遺傳多樣性及遺傳結(jié)構(gòu)對于評價(jià)和保護(hù)紅豆杉屬的遺傳資源具有重要理論價(jià)值。紅豆杉屬植物是第三紀(jì)孑遺物種,因此分子譜系地理學(xué)研究將為研究紅豆杉屬遺傳多樣性形成機(jī)制及推斷該屬物種遷移演化歷史提供依據(jù)。本論文選取全中國范圍內(nèi)的紅豆杉屬各種典型分布區(qū)植物樣本,開發(fā)并篩選出富含多態(tài)性的微衛(wèi)星標(biāo)記用于不同種群遺傳多樣性及遺傳結(jié)構(gòu)分析,同時(shí)開展了基于4個(gè)質(zhì)體DNA序列片段和1個(gè)核基因片段的基因變異來分析國內(nèi)現(xiàn)存5種紅豆杉(包括變種)的譜系地理關(guān)系及遺傳多樣性水平,從而推測種群的歷史動(dòng)態(tài),為制定遺傳資源的保護(hù)策略提供理論依據(jù)。主要研究成果如下:(1)紅豆杉屬植物64個(gè)種群具有較高水平遺傳多樣性。聯(lián)合的葉綠體序列片段得到44個(gè)單倍型,總的單倍型多樣性Hd=0.7368,總的核苷酸多態(tài)性π=0.00396;線粒體基因片段檢測出6種單倍型,整體的單倍型多態(tài)性Hd=0.4660,核苷酸多態(tài)性π=0.00066,HT=0.451。其中,東北紅豆杉HT=0.662,須彌紅豆杉復(fù)合類群HT=0.819;基于ITS基因序列檢測出73種單倍型,總體水平的單倍型多樣性Hd=0.9143,核苷酸多樣性π=0.00891,總的遺傳多樣性HT=0.813。其中,東北紅豆杉HT=0.750,須彌紅豆杉復(fù)合類群HT=0.831;12對SSR引物檢測我國紅豆杉41個(gè)種群的遺傳多樣性,共檢測288個(gè)等位基因,平均每個(gè)等位基因數(shù)為19.244個(gè),平均期望雜合度He=0.479,且群體內(nèi)的基因多樣度(Ht)的平均值為0.498大于群體間的基因多樣度(Hs)的平均值為0.282。綜合比較,西南地區(qū)的橫斷山區(qū)和秦嶺-大巴山區(qū)表現(xiàn)出高的遺傳多樣性,華東地區(qū)和華中地區(qū)及東北長白山區(qū)均表現(xiàn)相對較低的遺傳多樣性。(2)AMOVA分析遺傳結(jié)構(gòu)表明,基于質(zhì)體DNA序列分析結(jié)果為種群間遺傳變異顯著大于種群內(nèi)的遺傳變異,而基于核基因(ITS序列和nrSSR標(biāo)記)分析結(jié)果為種群內(nèi)的遺傳變異大于種群間遺傳變異水平。主要因?yàn)閲鴥?nèi)紅豆杉屬植物為雌雄異株,其葉綠體DNA和線粒體DNA都是父系遺傳,表現(xiàn)花粉流,而因其無花粉囊的花粉結(jié)構(gòu)及處于林下次層林的特征,阻礙了花粉的傳播而限制了花粉流,使得種群間變異大于種群內(nèi)的遺傳變異。而核基因遺傳表現(xiàn)為種子流,紅豆杉屬植物的果實(shí)味道香甜,顏色鮮艷,深得部分鳥類的喜愛,從而得到長距離傳播,促進(jìn)了種子流,而降低了種群間的分化。(3)本研究檢測到了紅豆杉屬植物的種群具有明顯的譜系結(jié)構(gòu)(核基因:GST=0.412,NST=0.792;葉綠體基因:GST=0.7840,NST=0.8280),NST均顯著大于GST(P0.001),從單倍型的嚴(yán)格一致性樹和network圖也可以看出,不同地區(qū)的單倍型得到較好的聚類,且Mantel檢驗(yàn)結(jié)果也表明,紅豆杉屬植物的種群間的遺傳距離與地理距離之間有顯著的相關(guān)性,這也就表明紅豆杉屬植物的種群間也存在一定的地理隔離影響,這也是紅豆杉屬植物的種群間遺傳分化和具有明顯的譜系地理格局的重要原因。(4)種群歷史上是否經(jīng)歷過擴(kuò)張的檢驗(yàn)結(jié)果表明,Tajima’s D檢驗(yàn)表明符合中性突變進(jìn)化,而失配分析的結(jié)果也未檢測到紅豆杉屬植物種群經(jīng)歷過近期擴(kuò)張,只有長白山區(qū)的失配分析曲線圖表現(xiàn)為單峰,說明長白山區(qū)的種群可能經(jīng)歷了擴(kuò)張。而從本研究所得的單倍型分布規(guī)律上看,主要存在兩種形式,其一很多種群都具有其獨(dú)特單倍型,其二,一些種群共享同一種單倍型,這些很有可能表明紅豆杉分布區(qū)經(jīng)歷過異域片段化,存在多個(gè)避難所。
[Abstract]:Chinese Taxus (Taxus L.) is rich in plant resources, wide distribution, flora Chinese (1999) there are three species and two varieties recorded. Due to excessive exploitation of people, are already endangered. So understanding the genetic diversity of natural populations of Taxus plants and genetic structure has important theoretical value for the evaluation of genetic resources and the protection of Taxus. Taxus is the third century relic species, so the research of molecular phylogeography for research on genetic diversity of Taxus species inferred that the formation mechanism and evolution history of migration and provide the basis. This paper selects the Chinese within the scope of all kinds of typical plants of the genus Taxus distribution samples, developed and selected micro microsatellite polymorphism rich for different population genetic diversity and genetic structure, and carry out the 4 plasmid DNA sequence fragment and 1 nuclear based for tablets Analysis of the existing 5 kinds of genetic variation of Taxus chinensis (including varieties) of the phylogenetic relationship and genetic diversity level, which suggested that the historical population dynamics, provide a theoretical basis for the protection strategy of genetic resources. The main research results are as follows: (1) the 64 populations of Taxus plants have a high level of genetic diversity. The obtained fragment combined with chloroplast sequences of 44 haplotypes, the haplotype diversity of Hd=0.7368, =0.00396 of the total PI nucleotide polymorphism; mitochondrial gene fragments detected 6 haplotypes, overall Hd= haplotype polymorphism 0.4660 nucleotide polymorphism, =0.00066, HT=0.451., HT=0.662 yew, Taxus wallichiana compound group HT=0.819; ITS gene sequence detected 73 haplotypes based on the overall level of Hd=0.9143 haplotype diversity, nucleotide diversity of PI =0.00891, the total genetic diversity of HT=0.813. In HT=0.750, yew, Taxus wallichiana compound group HT=0.831; 12 pairs of SSR primers to detect 41 of China's population genetic diversity of Taxus chinensis, were detected 288 alleles. The average allele number was 19.244, the average expected heterozygosity of He=0.479, and the gene diversity within populations (Ht) average a value of 0.498 was higher than that of inter population gene diversity (Hs) 0.282. comprehensive comparison is the average of the southwestern region of the Hengduan Mountains and Qinling Mountains Daba Mountains showed high genetic diversity in East China and central China and northeast Changbai Mountain region showed relatively low genetic diversity. The genetic analysis of AMOVA (2) the structure shows that the plastid DNA sequence analysis results of genetic variation among populations was significantly greater than the genetic variation within populations based on, based on nuclear gene (ITS sequence and nrSSR marker analysis) results among populations left for genetic variation within populations than The level of genetic variation. Mainly because the domestic Taxus plants dioecious, the chloroplast DNA and mitochondrial DNA is paternal inheritance, expression of pollen flow, and because of its no pollen sac and pollen structure and characteristics in the forest next storied, hindered the spread of pollen restricted pollen flow, the variation among populations greater than the genetic variation of population the nuclear gene expression. The genetic flow of Taxus seeds, fruit sweet taste, bright color, deep part of the bird's favorite, resulting in long distance transmission, promote the seed flow, and reduce the differentiation among populations. (3) pedigree structure obviously detected in this study of the genus Taxus the population (with nuclear genes: GST=0.412, NST=0.792; GST=0.7840, NST=0.8280: chloroplast genes), NST were significantly higher than that of GST (P0.001), from the strict consensus tree and haplotype network map can also be seen in different regions The haplotype has better clustering, and Mantel test results also show that there is a significant correlation between the genetic distance and geographic distance among the populations of Taxus species, suggesting that it will affect the existence of geographic isolation of Taxus species, the genetic differentiation is red bean fir species populations and important why has the obvious phylogeographic pattern. (4) whether the population history experienced expansion of test results showed that Tajima s D test showed that the neutral mutation evolution, and the mismatch analysis results also did not detect the yew species populations experienced a recent expansion, only the Changbai Mountain area mismatch analysis curves showed a single peak, Changbai Mountain district population may have experienced expansion. From this study, the haplotype distribution law point of view, there are two main forms, one is multi group has its The unique haplotype, the second, some populations share the same haplotype, which is likely to indicate that the Taxus distribution area has experienced a foreign region fragmentation, and there are many shelters.

【學(xué)位授予單位】：中國林業(yè)科學(xué)研究院
【學(xué)位級別】：博士
【學(xué)位授予年份】：2016
【分類號】：S791.49

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