海雀稗种质资源RAPD分子标记的遗传多样性研究

以来自广东省海雀稗的3个野生居群和1个草坪型栽培品种为材料,采用RAPD分子标记技术对其遗传多样性及在居群内和居群间的大小和分布格局进行了分析.结果发现,20条引物共扩增出176条带,其中114条带为多态性带,占总带数的64.77%.从Shannon信息指数分析的结果来看,居群内、居群间和总居群的遗传多性指数分别为0.023 0、0.276 7和0.299 7,遗传分化系数为0.923 3,表明在总的遗传变异中,有92.33%的变异存在于居群间,而只有7.67%的变异存在于居群内,充分反映了海雀稗无性繁殖的内繁育系统在遗传变异调节中的重要作用.UPGMA聚类分析的结果表明,来自4个居群的所有个体被分为2支,一支包括栽培品种和番禺居群,另一支包括珠海居群和广州市区居群,这一聚类结果与植株的高矮和茎的粗细等形态特征有一定的相关性.

Genetic diversity of seashore paspalum (Paspalum vaginatum)basded on RAPD molecular markers

Using the materials (Paspalum vaginatum Sw.) of three natural populations and one turfgrass cultivar from Guangzhou, Panyu and Zhuhai in Guangdong Province, the genetic diversities and their distribution pattern within and among populations were analyzed by means of RAPD molecular markers. The results showed that a total of 176 reproducible RAPD fragments were produced by using 10-mer random primers, with an average of 8.8 fragments per primer. One hundred and fourteen fragments (64.77% of the total observed) were polymorphic . By analysis of Shannon information index, the genetic diversity indexes within and among populations were 0.023 0 and 0.276 7 respectively, and the genetic diversity index of whole population was 0.299 7. The genetic differentiation coefficient was 0.923 3, which illustrated that total genetic variations among populations was 92.33% and variations within populations was only 7.67% . It also indicate that the inbreeding system of vegetative multiplication of seashore paspalum play an important role in adjusting the genetic variation of this species. UPGMA cluster analysis showed that all individuals from four populations were divided into two clades. One included turfgrass cultivar (Hawaii grass) and population Panyu, and another included population Guangzhou and population Zhuhai. The results are consistent with the morphological characteristics such as height and diameter of culm.