The pollen of 51 cultivars and forms in chinese date(Z.Jujuba Mill.)were observed in this study by the aid of PM.SEM and TEM.The results of obs- ervation had been mathematically treated by the method of cluster and ass- ociation analysis.Based on this,the things on evolution.classification and germplasm repository et al.of varieties were discused,and the following conclusions were reached. 1.Distance coefficient may reflect the genetic differences among vari- eties.According to the value of this coefficient...