The Highly Efficient Methods for Preparation of Rice Metaphase Chromosomes and DNA Fibres

The preparation of mataphase chromosomes and DNA fibres of rice is the key technique in the research of rice genome structure. However these techniques are still in deficiency at present. In this study, a method to prepare metaphase chromosomes with high efficiency was deve-lopped in rice. In the chromosome slides prepared using this method, there were mass of metaphase cells, less impurity, clear background, well dispersed chromosomes and well presered chromosome morphologies. The mitotic index of root cells is up to 25%. We also established a DNA fibres preparing method. Since cell wall is a main abstacle in the preparation of DNA fibres, thus nuclei ware isolated by chopping first, then lysed by SDS to release DNA, and DNA fibers were prepared by drawing DNA using a cover side. DNA fibres prepared by this method showed equally spread parallel thread with clear background, and were suitable for in situ hybridization analysis. The highly efficient methods to prepare rice metaphase chromosomes and DNA fibres will surely accelerate rice genome mapping and organization analysis.