Cytological And Genetic Study Of Apomictic Eulaliopsis Bianta

In this paper, the number of chromosomes in E. binata was investigated by the root tip squash method , its ploidy was analyzed by the karyptype and chromosomes behavior of the pollen mother cells meiosis. Genetic diversity in 12 populations of apomictic Eulaliopsis binata was evaluated by morphological observation and RAPD analyse ,as a result, 12 populations of E.binata were divided into different types. In order to study Elaliopsis binata genetics characteristic, combining with pollination biology, we analysed the origin of crossbreed offspring by RAPD in different types with significative diversity and furhter discussed its degree of apomixis1) More than 30 root tips in each of populations of E. binata were observed, separately, and 10-20 cells with dispersive metaphase chromosome were statistic, thereby obtaining the average number of chromosomes in root tips. In one study of 326 root tips, 308 contained 40 chromosomes and 18 had varying number of chromosome in E. binata, for example, some contain 80, 60, 30, 20 chromosomes, respectively, while the others appeared aneuploid. Therefore, we proposed that the somatic cells of E. binata contained 40 chromosomes ( 2n=40 ). Furthermore, it was noted that, few significant difference among those populations was found in E. binata , although some natural mutations exist in the root tip cells of E. binata, indicating a few individuals with differing ploidy in E. binata .2) The results of karyotype analysis presented the morphology in chromosomes was relatively small and the average absolute length in E. binata was 3.820±0.415μm. The 6th and 11st chromosomes belonged to sub-middle centromere, wherease, the other chromosomes attributed to middle centromere, presenting relatively high symmetry, more precisely, the nombre fondamental ( N. F.) is 80. Plus, we found that the ratio (the length of the longest chromosome/ the length of the shortest chromosome) was 2.6356, which was more than 2/1, and all chromosome arm ratios were not more than 1/2. According to the standard for classifying chromosome karyotype, established by Stetbbin, the karyotype of E.binata belonged to type 1B, and the formula of karyotype in E. binata was 2n=40=18m+2sm, depending upon the data derived from karyotype parameters.