氮沉降和养分添加对贝加尔针茅种群遗传多样性的影响

发布时间：2018-03-02 07:11

本文关键词： 贝加尔针茅 ISSR 遗传多样性氮沉降景观遗传学　出处：《内蒙古大学》2017年硕士论文　论文类型：学位论文

【摘要】：揭示生境异质性的遗传效应以及局域种群的微进化过程是生态学的基本内容。人为干扰引起的生境异质性的遗传效应是当前景观遗传学最为关注的现实课题。本文采用ISSR分子标记技术,对内蒙古草甸草原在模拟氮沉降下和养分添加情境下优势建群种贝加尔针茅(Stipa baicalensis)的遗传多样性和遗传结构进行分析,探索氮沉降对贝加尔针茅种群遗传多样性的影响,揭示种群遗传多样性与环境因子的相关性。本研究有助于深入揭示小尺度下生境异质性对贝加尔针茅遗传格局的影响、针茅植物的微进化过程及全球变化对其遗传多样性的影响。主要研究结果如下:1.贝加尔针茅具有丰富的遗传多样性。养分添加3年后贝加尔针茅在物种水平上,多态位点百分率为98.44%,遗传多样性指数Nei's指数和Shannon's指数分别为0.2784和0.4299;6年后,种群多态位点百分率为100%,Nei's指数和Shannon's指数分别为0.2828和0.4356,均有不同程度的增加。2.氮沉降对贝加尔针茅种群遗传多样性的影响具有时间效应,在短期内种群遗传多样性随着氮沉降水平增加而增加,但氮沉降水平在增加到两倍(即N2--5.0g/m~2/a)后对种群遗传多样性才具有促进作用;随着年限增加氮沉降(即N1--2.5g/m~2/a)对种群遗传多样性的影响也由抑制作用变为促进作用,当氮沉降水平增加到两倍时达到氮饱和点种群遗传多样性最高,且三个氮沉降水平处理的贝加尔针茅种群遗传多样性均有所增加,具体表现为N2(5.0g/m~2/a)N(10.0g/m~2/a)Nl(2.50g/m~2/a)CK。3.短期和长期添加P肥(10.0g/m~2/a)对贝加尔针茅遗传多样性均有抑制作用;添加NP混合肥(10.0gN+10.0P/m~2/a)对贝加尔针茅遗传多样性有促进作用,但促进效果不如单独添加N肥(10.g/m~2/a);随着养分添加年限增加,贝加尔针茅各养分添加处理的遗传多样性与CK 的相比为,NNPCKP。4.由小尺度养分添加引起的环境因子变化致使贝加尔针茅种群遗传分化结构发生变化,说明贝加尔针茅对这种环境因子的变化较为敏感,表现出植物在分子水平下对局域尺度不同环境因子具有不同的响应。
[Abstract]:It is the basic content of ecology to reveal the genetic effect of habitat heterogeneity and the microevolution process of local population. The genetic effect of habitat heterogeneity caused by human disturbance is the most concerned topic in landscape genetics. ISSR molecular marker technique was used in this paper. The genetic diversity and genetic structure of Stipa baicalensis, a dominant species of Stipa baicalensis, were analyzed in Inner Mongolia meadow grassland under simulated nitrogen deposition and nutrient supplementation, and the effect of nitrogen deposition on genetic diversity of Stipa baicalensis population was explored. This study is helpful to reveal the effect of habitat heterogeneity on the genetic pattern of Stipa baicalensis on a small scale, and to reveal the correlation between population genetic diversity and environmental factors. The main results are as follows: 1. Stipa baicarinus has abundant genetic diversity. After 3 years of nutrient addition, Stipa baicarpa is at the species level. The percentage of polymorphic loci was 98.444.The genetic diversity index (Nei's index) and Shannon's index (Shannon's index) were 0.2784 and 0.4299, respectively. The percentage of polymorphic loci was 0.2828 and 0.4356, respectively, and the percentage of Neis index and Shannon's index were 0.2828 and 0.4356, respectively. The effects of nitrogen deposition on the genetic diversity of Stipa baicalensis were time-dependent. In the short term, the population genetic diversity increased with the increase of nitrogen deposition level, but the nitrogen deposition level increased to two times (N2--5.0 g / m ~ (2 / a)) before it could promote the population genetic diversity. The effect of N deposition (N 1-2.5 g / m 2 / a) on population genetic diversity also changed from inhibition to promotion with the increase of the number of years. When nitrogen deposition level increased to two times, the population genetic diversity reached the highest at nitrogen saturation point. The genetic diversity of Stipa baicalensis population increased with three nitrogen deposition levels, showing that N _ 2 + 5.0 g 路m ~ (-1) 路m ~ (2 /) N _ (2) N _ (2) N _ (2) N _ (1) N _ (2) N _ (2) N _ (1) N _ (2) N _ (2) N _ (1) N _ (2) N _ (2) N _ (2) N _ (2) N _ (2) N _ (2) N _ (2) N _ (2) N _ (2) N _ (2) N _ (2) N _ (2. The addition of 10 g N 10.0 P / m 2 / a of NP fertilizer promoted the genetic diversity of Stipa baicalensis, but the effect was not as good as that of adding N fertilizer 10 g / m 2 / a. Compared with CK, the genetic diversity of Stipa baicalensis was NNPCKP.4.The genetic differentiation structure of Stipa baicalensis population was changed by the change of environmental factors caused by small scale nutrient addition. The results indicated that Stipa Baikal was sensitive to the change of environmental factors and showed that plants had different responses to different environmental factors at local scale at molecular level.
【学位授予单位】：内蒙古大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S812

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