Recent advances in studies of genetic variation at protein and DNA levels in plant natural populations and its relationship with environmental changes were reviewed with special reference to the works on the wild barley ( Hordeum spontaneum C. Koch.). On one side, adaptation was shown in statistic data, on the other side, the fact that a considerable part of genetic variation does exist within populations (subpopulations) under same ecological condition indicated its maintainability of neutral or near_neutral mutations in natural populations. The researches on adaptive populations of plants, especially on wild soybean ( Glycine soja Sieb. et Zucc.) mainly conducted in author’s laboratory, have shown that the most part of molecular variation within and among populations can not be explained by selection particularly as far as the individual uniqueness was concerned. There are some data shown that adaptation may be caused by accumulation of a few near_neutral mutations. Recent publications on molecular mechanisms of morphological evolution has been received special attention to elucidate the discrepancy between molecular evolution and morphological adaptive evolution. A frame on the unified evolution theory has been built. Finally some related viewpoints of philosophy were discussed.
黄河三角洲野大豆(Glycine soja Sieb. et Zucc.)盐渍群体的耐盐性高于附近的正常群体。群体内个体间耐盐能力差别很大。盐渍群体有比最耐盐的栽培大豆(G.max (L.)Merr.)品种耐盐能力高得多的个体,也有对盐相当敏感的植株。同工酶分析表明群体内高水半多态性,但酶谱与抗性没有相关性。盐渍与正常群体间的遗传一致性高达0.96。用改良的随机扩增多态DNA(RAPD)方法,10个引物扩增得出群体内多态位点百分数为68/188=0.36。看来,绝大多数位点与耐盐能力无关。上述资料说明,盐渍条件下野大豆自然群体的高度遗传多样性和发育变通性,可能足对盐胁迫强度随时随地变化的环境的适应。
