地黄属和崖白菜属等位酶的变异研究

Allozymic variability in Rehmannia and Triaenophora (Scrophulariaceae)

利用超薄平板微型聚丙烯酰胺凝胶的等电聚焦电泳技术,对玄参科Scrophulariaceae地黄属Rehmannia 6种植物和崖白菜属Triaenophora 2种植物共52份材料进行了7个酶系统的等位酶分析。在7个酶系中共检测到18个清晰位点和45个等位基因,多态位点为17个;并将遗传学数据用软件Biosys-1进行分析,结果表明:同种内个体间表现出较大的遗传同质性,而不同种的个体则表现出明显的趋异性。除高地黄R.elata和裂叶地黄R.piasezkii外,其余6种植物之间遗传分化较明显,8个种按聚类结果分为两支,崖白菜属的崖白菜T.rupestris和神农架崖白菜T.shennongjiaensis聚为一支,位于分支树的基部;地黄属的地黄R.glutinosa、茄叶地黄R.solanifolia、天目地黄R.chingii、湖北地黄R.henryi、高地黄和裂叶地黄为另一支。在地黄属中,高地黄和裂叶地黄之间的亲缘关系最近,地黄和裂叶地黄关系最远。本研究结果不支持把高地黄和裂叶地黄作为两个独立的种。地黄属与崖白菜属在遗传上具有较高水平的相似性,它们在生活史和形态学上仍然保留有许多共同的特征,说明它们之间分化的时间可能不长。

Fifty-two plant samples from six species of Rehmannia and two species of Triaenophora of Scrophulariaceae were investigated using ultra-thin slab IEF-PAGE in this study. The results showed that forty-five alleles of eighteen loci were present in seven enzymatic systems, and seventeen of eighteen loci were polymorphic. The data further determined by Biosys-1 indicated that individuals of the same species exhibited relatively strong genetic homogeneity, while individuals of different species showed statistically significant genetic heterogeneity. We also found that among the eight species, except R. elata and R. piasezkii, six showed relatively obvious statistically significant genetic differentiation. Moreover, the eight species could be placed into two groups according to cluster analysis; one group consists of T. shennongjiaensis and T. rupestris, and the other consists of R. glutinosa, R. solanifolia, R. chingii, R. henryi, R. elata, and R. piasezkii. The results also showed that in Rehmannia, R. elata and R. piasezkii were most genetically related to each other, while R. glutinosa and R. piasezkii were least genetically related. Allozyme study suggested that R. elata and R. piasezkii should not be regarded as two distinct species. Rehmannia and Triaenophora shared highly genetic identity with many similar characteristics in their morphology and life history, indicating their divergence time might not be very long.