Molecular ecology of plant populations using microsatellite genetic markers

1.以12个日本自然居群为材料，对拟南芥的29个基因座进行了微卫星多态性分析。所有受检个体在所有微卫星座位上均为纯合子。虽然群体间存在相当大的变异，但当研究了8个基因座时，3个被选群体没有检测到群体内多态。结果表明，所检测的微卫星是研究拟南芥天然居群间遗传变异的合适遗传标记。为了比较遗传相似性和推断种群间的进化关系，在两种不同方法计算的距离矩阵的基础上构建了邻接树。树木中揭示的种群间的遗传关系并不一定与它们的地理距离相对应。这可能反映了它们不同的起源或不同的入侵日本岛国的时间。2.对采自日本11个不同野生种群的海棠在四种不同条件下的表型可塑性进行了实验研究：(1)绿色春化-长日照(GVLD，16小时)，(2)GVSD(绿色春化-短日，8小时)，(3)LD(非春化-长日)，(4)SD(非春化-短日)。试验共包括440株植物(10个重复×4个处理×11个群体)。结果表明，除神奈川外，长日照和/或低温均能缩短开花天数，且长日照效果优于低温。两种处理的效果是相加的，因为长日照和春化处理配合使用对开花的促进作用最大。还记录了其他几种相关的性状变化模式，反映了种群和实验处理的起源。

1.Microsatellite polymorphisms of Arabidopsis thaliana were surveyed for 29 loci using 12 Japanese natural populations as material. All the individuals examined were homozygous at all the microsatellite loci. Although there was considerable variation among populations, no intra-population polymorphism was detected in three selected populations when eight loci were studied. The microsatellites examined proved to be a suitable genetic marker for studying the genetic variation among natural populations of A.thaliana. To compare the genetic similairty and infer the evolutionary relationships among populations, neighbor-joining trees were constructed on the basis of distance matrices calculated by two different methods. Genetic relationships among the populations as revealed in the trees do not necessarily correspond to their geographic telation-ships. This may reflect their different origins or different times of introudction into the lslands of Japan.2.Phenotypic plasticity of A.thaliana collected from 11 different wild populations in Japan was experimentally examined under four different conditions : (1) GVLD (green vernalization-long day, 16hrs), (2) GVSD (green vernalization-short day, 8hrs), (3) LD (no vernalization-long day), and (4) SD (no vernalization-short day). 440 plants (10 replicates*4 treatments*11 populations) were included for this experiment. The results indicate that long-day and/or low temperature shortened the days to flowering except Kanagawa, and long-day was more effective than low temperature. The effects of two treatments were additive because the flowering was most accelerated when the long-day and vernalization treatment were applied in combination. Several other correlated patterns of character changes were recorded, reflecting the origin of populations and experimental treatments.