钟花报春的种群遗传结构和繁殖性状分化

	钟花报春的种群遗传结构和繁殖性状分化
	贺雨婷
导师	周伟
关键词	微卫星标记，遗传结构，种群动态历史，繁殖性状，QST-FST SSR, Population structure, Population demographic history, Reproductive traits, QST-FST
摘要	钟花报春作为多年生草本，隶属于报春花属钟花报春组，在喜马拉雅山脉以及横断山区广泛分布，属于典型的高山类群，这也为研究该地区从第四纪到现在时间段的物种分化和迁移路线提供了理想的材料。本文选取钟花报春为研究材料，共选取分布于西藏、云南和四川的49个居群，约980个体，利用13对微卫星分子标记来检测青藏高原地区钟花报春的物种遗传多样性和种群遗传结构，并采用SSR数据结合ABC模型和生态位模拟来检验不同的种群分化模型以及种群分布历史从而评估不同冰期的影响。同时，我们测量了采集于上述地区的钟花报春47个居群，1410朵的花形态材料，每朵花选取10个繁殖性状进行形态数据分析，并计算不同性状的QST，与钟花报春的遗传分化系数FST进行比较，探究自然选择如何影响钟花报春的繁殖性状。本研究首先采用高通量测序设计合成并筛选得到13对多态性高的微卫星引物，手工研磨提取49个居群980个体的DNA，进行毛细管电泳基因分型。遗传多样性分析结果表明各居群的多态位点百分数非常高，大多数居群多态百分数达到90%以上，最低的居群多态百分数都有84.62%，遗传多样性水平也非常高(PPL = 94.6% , Ho = 0.54 , He = 0.54 , I = 1.11)。种群遗传结构表明分布于青藏高原地区的钟花报春可以划分为4个谱系，位于高原面的CD1和CD2谱系，由山南-林芝-察隅等地区构成的SN-LZ谱系以及集中分布于横断山区的HD谱系。主坐标分析和邻接树结果也支持四个谱系的划分，四个谱系中遗传多样性最高的是HD谱系。AMOVA分析结果表明，不论是居群或是分组水平，钟花报春物种的遗传分化水平都较高，遗传变异也主要发生在居群内。Mantel test分析结果表明遗传P < 0.01)。隔离障碍分析结果显示在HD谱系和其它三个谱系之间有一条明显的隔离带存在，这与当地的地形以及海拔有关。基于微卫星标记分析得到的群体遗传数据模拟钟花报春四个谱系的分化模式以及生态位模拟评估冰期对于钟花报春分布的影响。首先采用ABC模型设置参数、情形模拟得到最佳模型，计算结果显示HD谱系与SN-LZ、CD1和CD2谱系的共同祖先首先发生分离，而后SN-LZ谱系与CD1-CD2谱系发生分离，最后CD1谱系和CD2谱系分离。生态位模拟结果表明末次间冰期时钟花报春的模拟分布范围主要在横断山区，末次盛冰期的潜在分布范围发生扩张。将来的模拟分布范围相较于目前的分布范围也发生小范围的扩张。Maxent结果表明最湿季度平均温度、最暖季度降水量和等温性三个气候变量是影响钟花报春潜在模拟分布的主要因素。通过测量钟花报春的10个繁殖性状的形态学分析数据表明不同谱系间在多数性状上具有显著性差异，HD谱系在7个性状上与其它三个谱系呈现显著性差异，雌雄蕊距离除外。SN-LZ谱系和CD1谱系在6个性状中呈现显著性差异，花瓣宽度和雌雄蕊间隔不具备显著性差异。CD1谱系和CD2谱系相比，花冠筒开口大小、花瓣长度和宽度、花冠大小4个性状存在显著性差异。SN-LZ谱系与CD2谱系在花冠筒长度花萼长度以及花瓣长度3个性状之间存在显著性差异。不同谱系间性状间相关性强度不大。钟花报春的S型花中，柱头高度分布集中，花药高度呈现连续正态分布特征；L型花中，柱头和花药高度呈连续正态分布，花柱和花药都是互逆对生，符合异型花柱的雌雄异位特征。数量性状分化系数和遗传分化系数比较即QST-FST结果表明花冠筒长度和开口大小、花萼长度和宽度、花瓣长度和宽度以及花冠大小的 QST-FST显著大于中性性状的QST-FST预测值，以上七个繁殖相关性状表现出生境间适应性分歧，歧化选择导致不同居群中出现多样化的表型，产生小范围的局部适应性。青藏高原地区的钟花报春各居群都拥有较高的遗传水平，居群间分化明显，该种可分为4个地理谱系，有明显的谱系结构，四个谱系均发生过扩张，其中横断谱系最先发生分化，钟花报春物种在末次间冰期时发生扩张，末次盛冰期时分布范围发生收缩。四个谱系间的多数繁殖性状具有显著性差异，歧化选择在影响了钟花报春的群体分化，以上研究结果为理解青藏高原植物多样性形成机制提供了新证据。; Primula sikkimensis is a representative alpine plant species of Primulaceae family, a perennial herb widely distributed in eastern Himalayan-Hengduan mountain region. It is an ideal material for studying the species differentiation and species migration routes in Himalayan-Hengduan mountain region since Quaternary. In this paper, 49 populations of P. sikkimensis distributed in Tibet, Yunnan and Sichuan, about 980 individuals, were selected to detect the genetic diversity and population genetic structure of P. sikkimensis in Qinghai-Tibet Plateau(QTP) by using 13 pairs of microsatellite markers, SSR data combined with ABC compution and ecological niche modelling were used to test different population differentiation models and population distribution history to evaluate the impact of different ice ages. At the same time, we measured 1410 flower morphological materials of 47 populations of P. sikkimensis collected in the above region and selected 10 reproductive traits for morphological data analysis of each flower and calculated QST of different traits, compared with the genetic differentiation coefficient FST of P. sikkimensis, to explore how natural selection affects the reproductive traits of P. sikkimensis. In this study, 13 pairs of microsatellite primers with high polymorphism were first designed, synthesized and screened by high-throughput sequencing, and the DNA of 980 individuals in the above 49 populations was extracted by hand grinding and got genotype by capillary electrophoresis. The results of genetic diversity analysis show that the percentage of polymorphic loci in each population was very high, with the percentage of polymorphic loci in most populations reaching over 90%, the percentage of polymorphic loci in the lowest population reaching 84.62%, and the level of genetic diversity was also high (PPL = 94.6%, Ho = 0.54, He = 0.54, I = 1.11). The genetic structure of population showed that P. sikkimensis distributed in QTP could be divided into four lineages, CD1 and CD2 lineages located on the plateau, SN-LZ lineages composed of Shannan-Linzhi-Chayu and other region, and HD lineages concentrated in Hengduan mountain region. The results of PCoA and NJ tree also supported the division of four lineages, the highest genetic diversity among the four lineages was existed in HD lineage. The genetic differentiation level of P. sikkimensis was high both in the population level and the grouping level and the genetic variation mainly occurred within the population through AMOVA analysis results. Genetic distance and geographical distance showed significant positive correlation among different populations from Mantel test analysis (r = 0.20, P < 0.01). Barrier analysis results showed that there was an obvious barrier between HD lineage and other three lineages, which was related to the local terrain and altitude. The population genetic data based on microsatellite marker analysis was used to simulate the differentiation patterns of four linea
语种	中文
	2022-05
学位授予单位	中国科学院大学
文献类型	学位论文
条目标识符	http://ir.kib.ac.cn/handle/151853/75124
专题	昆明植物所硕博研究生毕业学位论文
推荐引用方式 GB/T 7714	贺雨婷. 钟花报春的种群遗传结构和繁殖性状分化[D]. 中国科学院大学,2022.

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