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该文研究分布在我国东喜马拉雅地区 (云南和西藏 )及四川的高山栎类种群间的形态变异和遗传距离 .在自然条件下 ,这些栎类的生长形态随纬度的增加和降水的减少从高大的乔木变成矮小的灌木 .该地区多样的气候和复杂的地形条件为高山栎类提供了各种形态、生长和遗传变异的可能性 .种群内和种群间的遗传距离随生境条件、山地地形和主风方向的变化明显 ,但与水平距离关系不大 .西藏地区以地势险峻和气候多变为特色 ,云南地区以高山峡谷为特色 ,二地区高山栎的种群遗传距离分别为 0 396和 0 36 5,前者显著高于后者 (P <5% ) ,但却都高于四川地区的高山栎种群遗传距离 ,并达到极显著水平 (P <1% ) .环境的异质性越高 ,高山栎类的变异越大 ,种群变异和物种进化与气候、生境、地形地貌和土壤等环境的异质性密切相关 .尽管东喜马拉雅地区是以大陆性季风为主气候特征 ,但高山栎类的叶片、直径和根系对环境异质性的适应变异与分布在地中海地区的、冬雨夏旱气候条件下的冬青栎类 (Q .ilex)十分相似 .不同地区的环境异质性必然导致物种进化和种群变异的差异 ,然而 ,高山栎类种群在两个截然不同气候区内的高度相似性恰恰说明了它们可能来自于一个共同的祖先或从同一个地区演化而来 ,所以它们才有相同的适应策略
In this paper, the morphological variation and genetic distance among alpine oak populations distributed in East Himalayas of China (Yunnan and Tibet) and Sichuan were studied.The growth morphology of these oaks increased with latitude and precipitation under natural conditions Of the trees become short shrubs.The diverse climate and complex terrain conditions in the area provide alpine oaks with a variety of morphological, growth and genetic variation possibilities.The genetic distance within and between populations varies with habitat conditions, mountain topography And the direction of the main wind changes obviously, but has little to do with the horizontal distance.The Tibetan region features steep terrain and climate change.The mountainous area in Yunnan is characterized by alpine gorges. The population genetic distance of the oak mountain oak is 0 396 and 0 The former was significantly higher than the latter (P <5%), but higher than the latter (P <5%), but higher than the genetic distance of Quercus acutissima population in Sichuan (P <1%). The higher the heterogeneity of the environment, Alpine oak species greater variation, population variation and species evolution and climate, habitat, topography and soil heterogeneity of the environment are closely related to the Although the East Himalayas are continental Winds are the main climatic characteristics. However, the adaptative variation of leaf, diameter and root system of alpine oaks to environmental heterogeneity is very similar to that of Q.ilex distributed in the Mediterranean in the winter rain and summer drought. Environmental heterogeneity in different regions inevitably leads to differences in species evolution and population variation. However, the high similarity between alpine oak populations in two distinct climatic regions shows that they may come from a common ancestor or from the same Regions evolved, so they have the same adaptation strategy