小麦幼胚体细胞无性系及其继代过程的微观结构观察

利用扫描电子显微镜,观察了由小麦“千斤早”和“小偃22”幼胚离体培养产生的体细胞胚性无性系继代过程中微观结构的变化,以及胚性无性系和非胚性无性系的结构差异。结果发现,小麦“千斤早”和“小偃22”的幼胚体细胞胚性无性系的微观结构存在较大差异,主要表现在体细胞之间的组织形式上,胚性无性系发生能力强的小麦具有较好的细胞组织形式,胚性无性系发生能力弱的小麦其体细胞组织形式也较差。随着继代次数的增加,体细胞胚性无性系在组织结构上趋于无序化,且这种无序化的进程也受到小麦基因型的影响:对于耐离体培养小麦,在经历多次继代后,组织的有序化程度仍然保持着较高的水平;对于胚性无性系产生频率低的小麦,不仅其早期培养过程中胚性细胞所占的比例较低,且组织间的有序性很快在有限的继代过程中趋于崩溃。

Microscopic observation on somatic clones from immature wheat embryos and on their changes during subcultures

With scanning electron microscope (SEC),changes of somaclones induced from immature wheat embryo during subcultures,and differences between embryogenic (EC) and non-embryogenic clones (NEC) were investigated.The results show that microscopically structural differences between NEC and EC are ascribed to different structural forms of embryogenic cells between wheat cultivars "Xiaoyan 22" and "Qianjinzao".Embryogenic clones with high induction frequency in "Xiaoyan 22" possess good cell organizaions,while EC with lower induction frequency in "Qianjinzao" possess relatively poor cell organization.Furthermore,the embryogenic clones show a tendency of disorder with variation between "Xiaoyan 22" and "Qianjinzao"."Xiaoyan 22" can survive the continuous subcultures,and its contact organization of cells can be retained with high order for a long time,while for "Qianjinzao",whose embryogenic clones were produced with low frequency,organization of its cells can only be retained in limited generations of subcultures and tend to break up.