水稻染色体G—带的研究

用改良的ASG法首次在籼稻(O.sativa subsp.indica)品种珍汕97和粳稻(O.subsp.iaponica)品种秀岭的有丝分裂染色体上显示了G-带,并作了相应的G-带核型分析。就同一材料来说,随着有丝分裂时期的推进,染色体上带纹数目逐渐减少。籼、粳亚种间相对应的同源染色体上G-带带纹特征彼此相似。讨论了水稻G-带带型与染色体不同区域分化的关系;G-带带型与籼、粳稻分歧的关系;以及G-显带的方法。

Studies of Chromosome G-banding in Rice (Oryza sativa)

Advanced ASG method of G-banding .was used in this study. Mitotic chromosome G-band-ing patterns and their corresponding karyotypes of rice cultivars Zhen Shan 97 (O. saliva subsp. indica) and Xiu Ling (O. saliva subsp. japonica) have been studied comparatively. Multiple adjacent bands were observed along the total length of each chromosome. Some of these bands were thick and intensively stained, the others were thin and lightly stained. Differences in G-banding patterns were found between nonhomologous chromosomes, there are while two members of each chromosome pair were similar in the numbers, size and staining degree of bands. Homologues can be matched exactly on the basis of G-banding patterns.Chromosome banding patterns including band numbers in three different mitotic stages of the same experimental material have been compared. Band number decreased gradually from prophase to metaphase. Thin and lightly stained bands in prophase combined into thick and intensively stained bands in metaphase. Chromosomes in late prophase showed the best G-banding patterns. We also compared banding patterns of indica with that of japonica in late prophase. The numbers, size and staining degree of bands between the two subspecies were basically the same.We have discussed the relations between G-bands and regional differentiation of chromosome, and those between G-banding patterns and the diversity of the two subspecies, as well as the key points of the method used in this study.