Morphological differentiation of seeds of the clonal herb Ligularia virgaurea in the eastern Qinghai-Tibet Plateau | 青藏高原东缘黄帚橐吾种子的形态分化研究

chinois. 研究青藏高原东缘黄帚橐吾种子大小的变异式样，及海拔高度对种子大小的影响。采集青藏高原东缘不同海拔高度分布的3个黄帚橐吾自然种群的种子，测量并计算种子的长度、宽度、高度、千粒质量等9项形态学指标，用单因素方差分析法评价各指标的变异程度，并对上述指标与种群分布的海拔高度和种子总体方差的相关性进行分析。①黄帚橐吾种子的表型性状在种群内和种群间均存在一定程度的变异，其中种子长/高的变异系数在3个种群内及各种群间均最高，而种子千粒质量的变异系数均最低，表明种子质量较稳定。②黄帚橐吾种群间种子表型性状的t检验结果说明，种群间已产生较明显的表型性状分化。③相关分析结果表明，海拔高度与黄帚橐吾种子表型性状之间存在一定程度的相关性，黄帚橐吾种子的表型性状随海拔升高表现出先增大后减小但总体增大的趋势；总体方差与种子长/高具有较高的相关性。种子长/高可以替代总体方差来衡量黄帚橐吾种子的整体形态;海拔是影响黄帚橐吾种子大小及变异的一个重要因素。

anglais. The seed size variation pattern of Ligularia virgaurea and the effects of altitude on seed size variation were studied in eastern Qinghai-Tibet Plateau. The seeds of L. virgaurea were collected from 3 natural populations with different elevations. Based on the data of 9 morphological characters of seeds, the seed size variability was analyzed by One-way ANOVA and t test, then the relativity about the morphological characters of seeds and altitude and vanriance was analyzed. ① The seeds traits of L. virgaurea exhibited certain differentiations in 9 morphological characters and the variation of coefficient of ratio of length to high of seed was the highest among and within the three populations of L. virgaurea, while the coefficient of variation of variation of seed weight was the lowest, indicating that seed weight was more stable than others among the characters studied. ② t test of the inter-populations morphological variations indicated that there was an evident differentiation among populations. ③ Correlation analysis suggested that morphological variation of seeds of L. virgaurea was correlated to elevation, indicating that elevation played an important role in morphological variation. The seeds traits of L. virgaurea showed an increasing pattern, and then a decreasing pattern with the increase of elevation, but there was an increasing trend in general; Variance of three dimensions (length, breadth and high) of seeds had higher correlation to SL/SH. SL/SH instead of the variance of three dimensions is more appropriate than others to measure the seeds overall pattern of L. virgaurea; Elevation is an important factor affecting the seed size and its variation.