Paleo-polyploidization Evolution And Recognition Algorithm Research In Pan-Brassicaceae Genome

Brassicaceae contains a large number of vegetable crops,has extremely important economic and agricultural value,and is a significant model plant for flowering plant research.Because arabidopsis thaliana,brassica rapa and other crops are representative in the evolution of brassicaceae ancient polyploidy,and genome sequencing has been completed,their provides important basic material for their genetic structure and functional evolution research.Firstly,based on genomic informatics,we reconstructed the list of homologous collinear genes associated with polyploidy and species differentiation.The evolution rates of different genomes were found to be significantly different by using multiple normal distribution methods to fit the evolution rate(Ks)of collinear genes for species differentiation.Based on the time of the same evolutionary event between brassicaceae and common ancestors,a method for correcting the distribution of Ks was proposed,and the events of key evolutionary events in brassicaceae were re-determined.It was inferred that two common ancient tetraploid events(? and ?)occurred in brassicaceae respectively from 101 to 114 million years ago and 62 to 70 million years ago and a total of hexaploid events occurred in Brassica(brassica rapa,brassica oleracea,etc.)about 38 to 43 million years ago.Secondly,a new algorithm was proposed which can identify ancient polyploid types and was proposed to determine differences in the retention of different subgenomes within the genome.The algorithm was obtained by the difference in the retain and loss level of the ancient subgenome retention in the pan-brassicaceae.The algorithm applied to identify the pan-brassicaceae,inferring four times of multiplication events in the evolution of the brassicaceae,which may all be allopolyploid events.Finally,different whole genome duplication events,especially the ancient doubling(?)shared by the brassicaceae,were found to be beneficial for the amplification of this family of gene copies through the Squamosa Promoter Binding Protein-like(SBP or SPL)for in-depth comparative analysis in pan-brassicaceae.In addition,based on phylogenetic analysis,it was found that homologous copies of the family gene appear the subgenome generated by the ancient doubling remains unbalanced and the rate of evolution in different genomes was unbalanced.In summary,the subject has carried out in-depth comparative analysis of the genomic structure of the main brassicaceae plants,constructed a multi-genomic collinearity comparison list,which provides important comparative genomics research resource for brassicaceae gene related research;Repeated genome evolution was compared and statistically analyzed,especially the identification algorithm for the difference in the retain of genomic retention of the ancient polyploidy gene was established,which is important for the inference of the ancient polyploid type of brassicaceae plants and other plant groups in the future.Figure 18;Table 13;Reference 71.