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29个微卫星位点的多态性进行了研究。所有被检个体在所有微卫星位点上均为纯合。虽然有相当大的群体间的变异，没有群体内的多态性检测在三个选定的群体时，8个位点进行了研究。微卫星检测被证明是一个合适的遗传标记，研究自然群体之间的遗传变异的拟南芥。为了比较群体间的遗传相似性，推断群体间的进化关系，采用两种不同方法计算距离矩阵，构建邻接树。树中所揭示的种群间的遗传关系并不一定与它们的地理亲缘关系相对应。这可能反映了它们的不同起源或传入日本岛屿的不同时间。2.在四种不同的条件下，对来自日本11个不同野生居群的拟南芥进行了表型可塑性研究：（1）GVLD（绿色春化-长日照，16小时），（2）GVSD（3）LD（绿色春化-长日照）;（4）SD（无春化-短日照）。本实验包括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，长日照和低温均缩短了开花天数，且长日照比低温更有效。长日照和春化处理的组合对促进开花的作用最大，因此两种处理的效果是加和的。其他几个相关模式的字符变化的记录，反映了人口和实验处理的起源。

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.