Morphological differentiation of seeds of the clonal herb Ligularia virgaurea in the eastern Qinghai-Tibet Plateau.

【Objective】 The seed size variation pattern of Ligularia virgaurea and the effects of altitude on seed size variation were studied in eastern Qinghai-Tibet Plateau.【Method】 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.【Result】 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.②t-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.【Conclusion】 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.