Abstract: A comparative study was conducted on the shape, size, and mass of diaspores of 21 main desert plants in the lower reaches of Tarim River. The diaspores includ ed 17 kinds of seeds and 4 kinds of fruits. Their shape was measured by three-d imension variance, size was measured by the sum of three-dimension, and mass was measured by 100-seed mass method. The diaspore shape of test plants varie d greatly, with that of Fabaceae being nearly spherical, and of Compositae great er deviating spherical (variance>005). Diaspore mass also had greater differ ence. There was a definite consistency between the trend of diaspore size and mass. The mean mass of perennial herb’s diaspore was 18% heavier than that of shrub and semi-shrub’s diaspore, though the perennial herb had le sser species than shrub and semi-shrub. Nine of the 21 main desert plants had p ersistent seed bank. 100% of Tamaricaceae and 100% of Compositae plants had papp us which is of significance for the dispersal and settling down of the diaspore.

Key words: Cymbopogon citratus, Volatile, GC-MS, Allelopathy