【作者】 金琳；

【导师】 陈少风；

【作者基本信息】 南昌大学 ， 生态学， 2010， 硕士

【摘要】 五节芒(Miscanthus floridulus (Lab.)Warb.ex Schum.et Laut)为禾本科(Gramineae)芒属(Miscanthus Anderss)多年生草本植物。五节芒地下茎发达,丛状生长,生态适应性幅度极广,是一种具有开发利用价值的植物。本研究采用ISSR分子标记对五节芒12个自然居群进行了遗传多样性和遗传结构的分析,目的是为了解五节芒居群的遗传多样性水平、遗传结构以及居群间的遗传分化,为五节芒资源的保护与开发利用提供理论依据。主要结果如下：建立了适合于五节芒的ISSR-PCR反应体系和反应程序。25μL体系中,10×PCR Buffer 2.5μL、Taq DNA聚合酶0.75 U.Mg2+1.5mmol/L、4×dNTP 0.2 mmol/L。PCR反应程序为：94℃预变性5 min；94℃变性45 s；50-60℃退火45s,72℃延伸1 min 20 s,45个循环；72℃再延伸7 min；4℃恒温保存。利用7条ISSR引物对五节芒12个居群共186个个体进行了扩增,共得到88条谱带,其中多态性条带为81条,结果表明,五节芒在物种水平的遗传多样性较高(PPF=92.05%;Na=1.9205,Ne=1.4941,Hpop=0.2911,I=0.4409)。分析表明,居群水平上的遗传多样性相对较低(PPF=43.85%,Na= 1.4385,Ne=1.2564,Hpop=0.1534,I=0.2286),其中靖安居群的遗传多样性最高。五节芒居群间存在较大的遗传分化,居群间的遗传分化系数Gst=0.4669,表明遗传变异主要表现在居群内。五节芒为多年生植物,分布范围广；生殖方式为有性生殖和营养繁殖,这些可能导致较高遗传多样性水平和较低居群遗传分化。UPGMA聚类分析和POPGEN结果把五节芒分成三支。经Mantel检验遗传距离与地理距离没有显著相关性(r=0.3086)。更多还原

【Abstract】 Miscanthus floridulus (Lab.) Warb. ex Schum. et Laut is an economically important plant. The study were to evaluate the genetic diversity and genetic differentiation of natural populations and present a scientific framework for the conservation and utilization of M. floridulus.We established the reaction system and amplified procedure suitable for M. floridulus, which was 25μL amplification reactions system containing 10×PCR buffer 2.5μL,1.5 mmol/L Mg2+,100 ng template DNA,200 mmol/L dNTPs,0.75 U Taq DNA polymerase. The optimal amplified procedure was as follows:after a pre-denaturing of 5 min at 94℃,45 cycles were performed with denaturing of 45 s at 94℃, annealing of 45 s due from 50-60℃, extension of 80 s at 72℃, a final extension step of 7 min at 72℃.We estimated the genetic diversity and genetic structure of 12 natural populations in Jiangxi province using ISSR. A relatively high level of genetic diversity was detected in M. floridulus using 81 polymorphic microsatellite locie. The ISSR analyses revealed a high level of genetic diversity at the species level (PPF= 92.05%,Na=1.9205, Ne=1.4941, Hpop=0.2911,I=0.4409); and a low level at the populations level (PPF=43.85%,Na=1.4385, Ne=1.2564, Hpop=0.1534, I=0.2286). The genetic diversity of Jing’an population(JA) was the highest.M. floridulus is a perennial species with a wide distribution; these characteristics could account for the relatively high genetic diversity we observed. Furthermore this species has outcrossing and incrossing breeding system, a situation amenable to high genetic diversity and low levels of genetic differen-tiation among populations (Gst= 0.4669). Divided into 3 groups, using UPGMA and POPGEN. Mantel test evealed no significant correlation between the genetic distance and geographic distance (r= 0.3086).更多还原