Genomes Structure Analysis Between Some Species Of Genus Oryza

1.Fluoreseence in situ hybridization （FISH） procedure was adopted to analyse thegenomes of japonica Nipponbare, indica Guangluai NO.4and Chinese common wildrice using the genome DNA and Cot-1DNA of Nipponbare as probes. Karyotypeanalysis between japonica, indica and Chinese common wild rice was also madetomparatively based on their similar band patterns of the hybridization signals. Theresults showed that genomic DNA and Cot-1DNA in three rice genome distributionand coverage is very similar, The coverage percentage （%） of Cot-1DNA inJaponica,Indica and Chinese common wild were47.13±0.18,45.89±0.22,44.24±0.21, demonstrating that, there is a high homology and close relationship betweenJaponica, Indica and Chinese common wild. But through the analysis of hybridizationsignals,the distribution of highly repetitive sequences on the3kinds of rice has itsown characteristics, indicating that moderately and highly repetitive DNA sequencesplayed an important role during the evolution of common wild rice to cultivated rice,at the same time,moderately and highly repetitive DNA sequences is also importantduring the process of indica-japonica genetic differentiation,to further integration theresults of GISH, the chromosomes which contain lower moderately and highlyrepetitive DNA sequences are more active in the rice genome composition.This studydemonstrated the use of Cot-1DNA FISH integration with adjusting thepost-hybridization washing stringency method in the study of genetic variationbetween species and subspecies and genetic differentiation between subspecies is veryeffective.2. In order to reveal the change of Oryza sativa ssp.indica╳Wild Rice BackcrossProgenies’genome,we adopted genome in situ hybridization （GISH） procedure toanalyse Oryza sativa ssp.indica zhenshan97and4pedigrees of the Oryza sativassp.indica╳Wild Rice Backcross Progenies using the genome DNA of zhenshan97asa probe.The result showed that the signal of the probe can be found in allchromosomes of the4pedigrees,but the distribution of the probe is different.Non-traditional recombination and transposition may result in this phenomenon.Wealso find GISH is a valid way in Comparative genomics Analysis of BackcrossProgenies of distant hybridization of rice.3. Fluorescence in situ hybridization was adopted for comparative karyotype analysisof O. rufipogon with the Restriction Fragment Length Polymorphisms （RFLPs） as probes, These RFLPs based on the comparative Restriction Fragment LengthPolymorphism map between O. sativa and O. officinalis. The results showed thatthose chromosomes of O. rufipogon in this research did not followed the general rulethat the length of chromosome decreases with the chromosome number increases. It isobviously different from the general karyotype analysis. The results are based on thecomparative genetic maps and integrated the general karyotype analysis. It is in thecomparative genomics and the cellular level, and will facilitate the comparativeanalysis on different species in the same genus.4. Phylogenetic relationships were inferred using nucleotide sequences of the tribeOryzeae gene matK and nad72^ndintron sequence.The results tell us the character ofthese two sequence in tribe Oryzeae. Neighbor-joining phylograms of these twosequences in tribe Oryzeae were created based on the two sequences.The writer alsofound that the evolution speed of nad72^ndintron sequence is slower than theevolution speed of matK.In these study,the writer also discussed the possibility formatK and nad72^ndintron sequence to become the DNA barcoding.5.In these paper, flow cytometry was used to find out the genome size of O.grandiglumis、O. alta and O. latifolia。The genome size of O. grandiglumis is about548.8Mbp; The genome size of O. alta is about784Mbp; The genome size of O.latifolia is about1117.2Mbp.