A Cytological Investigation on the Divergence Related to Numbering System for Chromosome 9 and 12 in Rice
对水稻第9和第12染色体编号分歧的细胞学考证 A Cytological Investigation on the Divergence Related to Numbering System for Chromosome 9 and 12 in Rice

Rice chromosomes in mitosis arc usually too small to be identified clearly one from others. In recent years, pachytene chromosomes in meiosis have been investigated intensively for establishing unified numbering system. However, divergence in numbering system is still existing especially for some short chromosomes such as chromosome 9 and 12. In order to verify these chromosomes, a translocation line RT9-12 and a japonica variety Nipponbare were carefully investigated for all the chromosomes morphologically in late pachytene stage. It was found that the chromosomes involved in translocation wcre chromosome lo and 11 in stcad of chromosome 9 and 12 as being compared with the karyotype of Nipponbare. So we consider that the chromosome 9 and 12 in the present rice chromosome numbering system could be chromosome 10 and 11 according to their length, arm ratio and the relationship with nucleolus.