柱花草种质的RAPD多态性和对炭疽病的抗性分析

RAPD Analysis of Genetic Variability Among Stylosanthes guianenesis Accessions Resistant and Susceptible to Stylo Anthracnose

利用RAPD技术分析了45个柱花草品种的遗传多样性和抗病性,从200条随机引物中筛选出20条引物进行扩增,其多态性水平为71.5%。根据RAPD扩增结果,采用非加权成对平均数法(UPGMA)对45个柱花草品种进行了聚类分析并建立了树系图,其遗传相似系数为0.5￣0.94,在0.665水平上分为14类(A￣N)。通过盆栽植株接种我国2种典型的柱花草胶孢炭疽菌试验进行了抗病性筛选,结果表明:抗病品种对2种病原菌的抗性相关系数为0.904。应用多重对应分析(MCA)方法对RAPD扩增结果和柱花草品种抗性鉴定结果进行了分析:分为6类并计算了每一类的平均距离;除第1类外,柱花草对试验采用的2个炭疽菌生理小种的抗病性或感病性在其RAPD所检测到的遗传多样性分类中呈随机分布,表现出高度的多样性。

Forty-five accessions of Stylosanthes were to anthracnose. RAPD analysis was made using twenty assessed with RAPD for genetic diversity and for resistance primers screened from 200 arbitrary oligonucleotides, and a 71.5 % level of polymorphism was found. According to the RAPD data, the dendrogram obtained with unweighted pair group method of averages （UPGMA） showed genetic similarity ranging from 50 % to 94 % among all stylo accessions, and fourteen clusters were defined at 66.5% genetic similarity. Two strains of Colletotrichum gloeosporioides from stylo in China were used for anthracnose resistance screening. All the accessions showed variation in the reaction to the two strains and had a correlation of resistance of 0.904. Multiple correspondence analyses displayed a random distribution of the resistance or susceptibility response with respect to the genetic diversity measured by RAPD analysis except one group. Mean distance was also calculated to determine the diversity within clusters. Our studies show that the RAPD analysis is an effective and efficient technique for providing quantitative estimates of genetic similarity among stylo accessions.