南岭山地南方红豆杉遗传变异与气候因子相关性研究

发布时间：2018-05-30 15:06

本文选题：南方红豆杉 + 遗传多样性　；参考：《中南林业科技大学》2017年博士论文

【摘要】：南方红豆杉是我国特有树种,属第三纪孑遗物种,被列为国家Ⅰ级重点保护野生植物。南岭山地拥有大量的古老残遗植物,是古代针叶树的分布中心和避难所,为南方红豆杉分布的南界。南岭为我国少有的横向山脉,并由众多不连续的山体构成,分布大量盆地、沟谷和河流,形成多样化的气候特征和小地形微环境,导致了南方红豆杉群体的生境多样性和遗传多样性。本研究应用回归模型和ArcGIS中普通克里格(Ordinary Kriging)法进行气候因子插值和修正,获得23个南方红豆杉自然分布群体的气候因子,并结合形态、细胞解剖和微卫星(SSRs)标记技术,对南岭山地南方红豆杉自然地理分布、生境气候特征、遗传变异进行综合的研究,为南方红豆杉保护单元的分类和保护提供科学依据。主要研究结果如下:(1)南岭23个南方红豆杉群体分布区的年平均气温(AMT)在12.175～18.263 ℃之间,最适气温范围为14.972～18.492 ℃,平均值为16.732 ℃;Kira温暖指数(WI)在86.381～160.420 ℃·月之间,最适气温范围为118.811～162.353℃·月,平均值为140.582 ℃·月;Kira寒冷指数(CI)在-4.262～-1.196 ℃·月之间,最适气温范围为-2.885～-1.169℃·月平均值为-2.027℃·月;徐文铎湿润指数(HI)9.264～13.687mm·(℃ ·月)-1,最适范围9.689～11.909 mm·(℃·月)-1,平均值10.799mm·(℃·月)-1;可能蒸散率(PER)范围0.159～0.939,最适范围0.416～0.906,平均值0.661;年均降水量(AMP)1147.996～1591.286 mm,平均值1452.643mm、年均相对湿度(AMRH)77.473～82.347%,平均值79.128%;日照时数(SD)1194.318～1785.059h,平均值 1509.458 h。按 Penman植被-气候分类系统、Holdridge生命地带分类系统和Kira温度指标进行分类,南方红豆杉属于亚热带湿润森林生命地带的树种,气候类型为暖温带湿润气候型。极端温度因子、热湿综合因子、地理因子3个主成分依次对南方红豆杉地理分布起主导作用。南方红豆杉群体分为三个区,其中高海拔的桑植县(Hnbd)和融水县(Gxyb1)聚为一区,第二区是东部,包括广东、江西、福建、浙江、广西融水县(Gxyb2)和湖南攸县(Hnyx)的群体;第三区是西部,包括湖南西部、广西的资源县(Gxme)和龙胜县(Gxhp)、贵州的台江县(Gztj)的群体。地理空间与气候因子相关性分析表明,多数气候因子与纬度呈负相关关系,经度与干燥度指数、日照时数呈极显著负相关。海拔梯度与大多数的气候因子呈显著或极显著相关性。各群体海拔分布范围主要在500～1000m之间。(2)代表南方红豆杉海拔分布上下限的桑植县、攸县和融水县(Gxyb1)3个群体的表型遗传多样性都较低;叶长、叶宽的变异系数均小于或等于15%;叶长、叶宽呈桑植县群体攸县群体融水县群体;融水县群体的叶长和叶宽均与桑植县群体、攸县群体间存在极显著差异,而攸县群体与桑植县群体间差异不显著;3个群体间叶长宽比差异不显著。3个群体的叶片长度、宽度、长宽比与经度、纬度相关性不显著;叶片长度和长宽比与海拔梯度呈显著负相关,叶宽与海拔相关性不显著。融水县的元宝山群体的低海拔(1500～1600m)、中海拔(1700～1800m)、高海拔(1900～2000m)3个海拔梯度的叶长、叶宽、叶长宽比与海拔梯度呈显著相关性;在低海拔叶长和叶宽明显大于中、高海拔,中、高海拔叶长和叶宽差异不大。广西融水县、湖南攸县和河南鲁山县三个群体叶片组织结构都呈现出耐弱光、耐寒、喜潮湿的特征,但在结构特征上,融水县南方红豆杉与鲁山县中国红豆杉的相似度较高,与桑植县和攸县的南方红豆杉差别较大,因此,融水县南方红豆杉需进一步鉴定。桑植县群体的种子先端以微有二纵脊或三纵脊居多,攸县群体中发现有四纵脊种子。桑植县群体的同期幼苗侧生叶和叶片比攸县群体的数量多。(3)对南岭山地的9个南方红豆杉代表性群体,利用13个微卫星位点共217个个体进行分析,研究结果表明,南岭地区南方红豆杉遗传多样呈中等偏下水平(He=0.459),群体内自交程度较高(FIs=0.249)。群体间存在的显著的遗传分化(Fst=0.251,P0.01),基因流Nm为0.7461。群体间呈现按地理距离、气候因子聚类的趋势,其中融水县(Gxyb1)和桑植县群体与其它群体存在较远的亲缘关系。在垂直分布上,八大公山4个海拔梯度群体的等位基因数(Na)平均值为4.02,期望杂合度(He)平均值为0.48,Shannon指数(I)平均值为0.92,表明八大公山南方红豆杉具有中等程度的遗传多样性。低海拔区域群体的遗传多样性高于高海拔区域群体,其中Bd4群体和其它低海拔群体间存在显著的遗传分化和遗传距离。4个海拔梯度的群体内基因流都较为充足(Nm1),高海拔区域明显的气候差异可能是导致群体间遗传分化的主要原因。在大尺度上,9个群体的Shannon's信息指数(I)和期望杂合度(He)仅与海拔呈显著负相关(P0.05),与经度、纬度的相关性都不显著。在小尺度上,分宜县、双牌县、攸县和融水县4个群体在低海拔范围的气候因子和遗传多样性水平都较相似,呈现较高的遗传多样性,且与海拔梯度的相关性不显著,而高海拔的融水县群体因低温高湿而呈现较低的遗传多样性水平。(4)气候因子与遗传多样性参数相关性分析表明,Shannon's信息指数(I)与极端最高温(MWMT)、7月平均温(TAV07)、可能蒸散率(PER)呈极显著正相关,与kira寒冷指数(CI)呈显著正相关;与徐文铎湿润指数(HI)、相对湿度(RH)呈极显著负相关,与干燥度(K)呈显著负相关。期望杂合度(He)与PER呈极显著正相关,与干燥度(K)呈极显著负相关,与MWMT、气温年较差(TD)、夏季热湿比(SHM)、TAV07呈显著正相关;体现出气温、气温年较差和干燥度的增大,湿度减小,都会导致南方红豆杉群体的遗传多样性增大。固定指数(F)与全部气候因子的相关性都不显著,说明气候因子对南方红豆杉的生殖交配模式影响较小,推断是地理隔离、人为干扰等因素对其生殖交配系统影响较大。(5)总体上,各群体表现出较丰富的遗传多样性,群体间分化明显(Fst=0.251,Nm1)。保护策略可采取就地保护,辅助人工促进更新,维持群体遗传多样性。
[Abstract]:Taxus chinensis, a unique tree species in China, belongs to the third relict species of relict species, and is listed as a national key protected wild plant. Nanling Mountain has a large number of ancient residual plants. It is the distribution center and refuge of the ancient conifers. It is the southern boundary of the southern Taxus. Nanling is a rare horizontal mountain in China and is a large number of discontinuous mountains. A large number of basins, valleys and rivers, forming a variety of climatic characteristics and small terrain microenvironment, caused the habitat diversity and genetic diversity of Taxus chinensis population in the south. This study applied the regression model and the common Craig (Ordinary Kriging) method in ArcGIS to interpolate and amend the climatic factors, and obtained 23 Taxus chinensis. Natural distribution of climatic factors, combined with morphology, cell anatomy and microsatellite (SSRs) labeling technology, study the natural geographical distribution, habitat climate characteristics and genetic variation of Taxus chinensis in Nanling Mountain, and provide scientific basis for the classification and protection of Taxus conservation unit in southern China. The main results are as follows: (1) Nanling 23 The annual average temperature (AMT) in the population distribution area of Taxus chinensis was between 12.175 and 18.263 C, the optimum temperature range was 14.972 ~ 18.492 C, the average value was 16.732, and the Kira warm index (WI) was between 86.381 and 160.420 centigrade, and the optimum temperature range was 118.811 to 162.353 centigrade, and the average was 140.582 degrees centigrade; Kira cold index (CI Between -4.262 ~ -1.196 and month, the optimum temperature range is from -2.885 to -1.169 centigrade. The average value is -2.027 / month; the Xu Wenduo wetting index (HI) is 9.264 ~ 13.687mm (c) -1, the optimum range is 9.689 ~ 11.909 mm (centigrade) -1, the average value 10.799mm (centigrade month) -1, the range of possible evapotranspiration is 0.159 ~ 0.939, and the optimum range is 0.416 ~ 0.906, average value of 0.661, average annual precipitation (AMP) 1147.996 ~ 1591.286 mm, average value 1452.643mm, average annual relative humidity (AMRH) 77.473 ~ 82.347%, average value 79.128%, sunshine hours (SD) 1194.318 to 1785.059h, average 1509.458 h. according to Penman vegetation climate system, Holdridge life zone classification system and Kira temperature index. Taxus chinensis is a kind of tree species in the subtropical humid forest life zone. The climate type is warm temperate humid climate type. Extreme temperature factors, heat and humidity synthetic factors and geographical factors are the 3 main components of Taxus chinensis geo distribution in turn. The southern Taxus population is divided into three regions, in which the high altitude Sangzhi county (Hnbd) and thawing are in high altitude. Water county (Gxyb1) is divided into one area, the second area is the eastern part, including Guangdong, Jiangxi, Fujian, Zhejiang, Guangxi meltwater county (Gxyb2) and Hunan Youxian (Hnyx); the third is the western region, including Western Hunan, Guangxi resources county (Gxme) and Longsheng county (Gxhp), Guizhou's Taijiang county (Gztj). There was a negative correlation between the number of climatic factors and latitude. The longitude was significantly negatively correlated with the dryness index and the sunshine duration. The elevation gradient was significantly correlated with most of the climatic factors. The altitudes of each group were mainly between 500 and 1000m. (2) Sangzhi County, Youxian and meltwater representing the upper and lower limits of the altitude distribution of the South Chinese red bean The phenotypic genetic diversity of 3 groups in the county (Gxyb1) was low; the leaf length and the variation coefficient of leaf width were all less than or equal to 15%. The leaf length and leaf width were in the Youxian group of Sangzhi County group. The leaf length and leaf width of the Rong Shui county group were significantly different from the Sangzhi population and Youxian population, while the differences between Youxian and Sangzhi County groups were different. No significant difference between the leaves length and width ratio of the 3 populations was not significant. The leaf length, width, length width ratio and latitude correlation were not significant; the leaf length and length width ratio were negatively correlated with the elevation gradient, and the correlation between leaf width and altitude was not significant. The low altitude (1500 ~ 1600m) and middle altitude (1700 to 1800m) of Yuanbaoshan population in meltwater county were not significant. The leaf length, leaf width and leaf width ratio of 3 elevation gradient in high altitude (1900 to 2000m) were significantly correlated with the elevation gradient, and the leaf length and leaf width of the lower altitudes were obviously larger than those in the middle, high altitude, middle, high altitude leaf length and leaf width were little different. The leaf tissue structure of three populations in Guangxi Rong Shui county, Hunan Youxian and Henan of Henan showed weak light tolerance and tolerance. The characteristics of cold and humid, but in the structural characteristics, the South Taxus chinensis in Thu county is similar to that of Taxus chinensis in Lushan Mountain County, which is different from that of Taxus chinensis in Sangzhi and Youxian. Therefore, Taxus chinensis in Thu county needs to be further identified. The seeds of the Sangzhi County population are mainly with two longitudinal ridges or three longitudinal ridges, and Youxian population in Youxian population. It was found that there were four longitudinal ridge seeds. The seedling side leaves and leaves of the Sangzhi County group were more than the Youxian population during the same period. (3) a total of 217 microsatellite loci were analyzed with 13 microsatellite loci. The results showed that the genetic diversity of Taxus chinensis in Nanling area was in the middle level (He=0.459 In the group, the degree of self intersection is high (FIs=0.249). The significant genetic differentiation (Fst=0.251, P0.01) exists among the groups, and the gene flow Nm is a tendency to cluster among 0.7461. populations according to geographical distance and climate factors. Among them, the Gxyb1 and Sangzhi County populations have a far relative relationship with the other groups. In the vertical distribution, the 4 seas of the eight grand mountains are in the vertical distribution. The average value of allele number (Na) was 4.02, the average value of expected heterozygosity (He) was 0.48, and the average value of Shannon index (I) was 0.92, indicating that the genetic diversity of Taxus chinensis in the eight grand mountains was of moderate genetic diversity. The genetic diversity of the low altitude region population was higher than the high altitude regional population, among which the Bd4 population and other low altitude populations were in the low altitude population. There were significant genetic differentiation and genetic distance between.4 elevation gradient populations (Nm1), and the obvious climatic difference in high altitude region may be the main cause of genetic differentiation among populations. On large scale, the Shannon's information index (I) and expected heterozygosity (He) of the 9 populations were only negatively correlated with the altitude (P 0.05) there is no significant correlation with longitude and latitude. On the small scale, the climate factors and genetic diversity levels of the 4 groups in the county, Shuangpai County, Youxian and FOK Shui county are similar at low altitudes, showing higher genetic diversity, and not significant with the elevation gradient, while the high altitude meltwater County population is low temperature and high humidity. (4) the correlation analysis between the climatic factors and the genetic diversity parameters showed that the Shannon's information index (I) and the extreme temperature (MWMT), the average temperature (TAV07) in July, the possible evapotranspiration rate (PER) and the Kira cold index (CI) showed significant positive correlation, and the relative humidity (RH) with the Xu Wenduo wetness index (HI), and the relative humidity (RH). There was a very significant negative correlation and a significant negative correlation with the dryness degree (K). Expected heterozygosity (He) had a very significant positive correlation with PER, and had a significant negative correlation with the drying degree (K). It had a significant positive correlation with MWMT, the temperature range (TD), the summer heat and humidity ratio (SHM), and TAV07, and the temperature, the increase of temperature and the drying degree, the decrease of humidity, and the decrease of humidity could lead to the south. The genetic diversity of Taxus population increased. The correlation between the fixed index (F) and all climatic factors was not significant, indicating that the climatic factors had little influence on the reproductive mating pattern of Taxus chinensis. It was inferred that geographical isolation and human disturbance had great influence on the reproductive mating system. (5) in general, the groups showed abundant remains. The diversity of populations was significantly different (Fst=0.251, Nm1). Protection strategies could be protected locally, assisted by artificial promotion, and maintained genetic diversity.
【学位授予单位】：中南林业科技大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：S791.49

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