摘要
应用显微分光光度技术测定的稻胚发育过程中核DNA含量的结果表明，球形胚中细胞核DNA含量较高，多倍性明显，C值较集中在6－12C，个别的最高达238或439C，它们可能为胚柄细胞；DNA含量差异明显可能与它们的分化潜能有关。分化初期、中期及成熟胚细胞核DNA合量一般不及球形胚高，不同倍性的频率分布亦较球形胚分散，但多倍性仍明显；胚分化完全后胚细胞核DNA含量较多变动在20－56C范围内，但盾状体细胞核DNA含量明显高于胚芽、胚根原基。说明胚器官原基间核DNA的增殖或复制特点不同。核DNA含量高和不同器官原基间差异复制的不同可能是胚分化的前兆和基础。
Nudear DNA content was de tendned for globular, fferentiating and mnaturing embrys during rice embryognesis. Measunnnt of nulear-DNA was done microspectro-protometrically using late prophase nuclei in Feulgen-DNA stained embryo squashes. The results show tha differences in nuclear DNA Content between embryos at varioous developmental stages. The nuclei measured in the globular embryo showed DNA values varyin from 6 C to 12 C, i. e.,they were polyploid (Fig. 1). The highest DNA values found in the embryo were 238 C or 439 C. These cells may be lo cated in the suspensor of early devlelop ing embrys. At later developmental stages of rice embry, the nuclear DNA values varied from 20 C to 56 C(Figs. 2 ～ 5). But the cells in the Scutellum had higher C values than those in plumule and in primary radicle (Fig. 5S) These results of nuclear-DNA measunnnts for nuclei in globular embryo as well as in different primordia in differentiated em brys offer strong evidence for differential DNA edcation during rice embryogene sis. In addition, the higher DNA contens and the differential DNA replication may be an early symptom or the basis of cell differentiation during embryogenesis.
基金
中国科学院基金!87-49-04
关键词
稻
胚胎发育
核DNA含量
多倍性
差异复制
rice, embryogenesis,nuclear-DNA content, polyploidy, differential DNA replication
