Optimization Of Chromosome Sectinoing And Karyotype Analysis Based On FISH In Prunus Mume

The chromosome study of plants is an important prerequisite of gene location and physical mapping. The karyotype analysis of Prunus mume is commonly achieved by regular method of chromosome sectioning. However, using the cell-biology methods to achieve the karyotype has not been published yet. One reason is that P.mume is a kind of woody plants. The other reason is chromosomes of P.mume are extremely small and short. Thus, the chromosome sectioning method needs to be improved. In the study, the preferable method of chromosome sectioning was picked out. Besides, different kinds of materials were tried in order to make chromosome sectioning of P.m ume all the year around possible. Meanwhile, it was the first time to localize the maize45SrDNA on metaphase chromosomes of P. mume by fluorescence in situ hybridization (FISH) and Karyotype analysis was achieved based on FISH. The main results showed as follows:1. The limitation of materials in chromosome sectioning of P. mume was broke.There were three other materials, including immature seeds, growing points by root tissue culture, growing points of one-year-old seedlings.They were all proved to be served as materials as well.2. The pretreatment is eliminated in the improved flame and air-dried method of sectioning.The materials were put in fixed acetic acid-alcohol directly when they were obtained. This process maed the chromosomes stretch to a great extent. Besides, it was convient for FISH observing and improved the efficiency of chromosome sectioning.3. Three pairs of45SrDNA signals were detected in all metaphases examined, which were mainly distributed on Chormosomel,3and7. The situation may different in different varieties. The results provided some evidence to classification of P.mume.45SrDNA signals were all located at the distal of the long arms of chromosomes. Combining with karyotype parameter, it can be concluded that the evolution of P.mume. was quite low.The fluorescence in situ hybridization was successfully applied to P. mume. It was meaningful and helpful to make exact karyotype analysis, gene locations and physical mapping.