Karyotype Analysis Of The Chromosomes Of The R. Rubescens And FISH Analysis Genome Of The Oryza.alta And O.latifolia

1.The number and karyotype of the Rabdosia rubescens (Hemsl.) Hara was studied by using G-band method in this work. The results shows that the chromosome number of the specie is 2n=2x=24, constitution of relative length was 2n=10M2+14M2,karyotype formula was K(2n)=2x=24=16m+8sm. The accuracy of karyotyp analysis of the choromosome was improved by bands of the G-band because it can revealed the struction of the chromosomes . Base on the result of chromosomal characteristics, speculated that the R. rubescens was speculated that belong to the more original species.2.Fluorescence in situ hybridization (FISH) procedure was employed to investigate relationships and comparative analysis between Oryza.alta and O.latifolia with the probe of C0t-1 DNA from O.alta.The homologous category on karyotype analysis of the Oryza.alta and O.latifolia, base on the banding of C0t-1 DNA which the homologous chromosomes shows the similar signal bandings of C0t-1 DNA.The result showed that all the chromosomes displayed signals which mainly located in the centromere of chromosomes, the proximal centromere and the telomere, while the 24 chromosomes present shrong sigals than the other 24 in both two species.More interesting, the strong signals of the two amphidiploid species which has the same CCDD genome appeared similar while their weak sigals is different, according to the previously shudy,it is concluded that the similar part is belong to the C genome and the different part is may belong to the D geonome. The results above reveal that C0t-1 DNA has its high specificity to a certain genome/species during evolution, and it can be used as a probe in FISH for studing the relationships of species more effiently. Moreover, according to comparative analysis of the highly repetitive sequence and the moderate repeats of O.alta and O.latifolia using FISH based on the C0t-1 DNA probe from O.alta, the origin mechanism of allotetraploid in genus Oryza was also discussed. 3.Fluorescence in situ hybridization (FISH) procedure was employed to investigate relationships and comparative analysis between Oryza.alta and O.latifolia with the probe of gDNA from Oryza officinalis Wall.in the.in a right hybridization strict the probe can identified the C and D genome.because of the hight homologous.shows the strong signal.The results shows the signal on the chromosomes C and D genome is different.the shrong signal chromosomes belong to the C genome while the others weak signal The result shows that the CCDD of the O.alta cannot identified the C Genome clear as 24 chromosomes while the O.latifolia can.It is shows that there are very different between the two CCDD genomic species. The origin of allotetraploid in genus Oryza was also discussed.