Comparative Analysis Of Wheat Ancestors A, D And Rice Genomes

Wheat and rice are two of the world’s three major crops,with the largest production in the world of wheat and the second of rice.The genetic development and utilization of wheat and rice have greatly promoted the production and cultivation of high-quality stress-resistant varieties.During the evolution of wheat,wild resources are continuously replaced by bred varieties,which increase the wheat yield while sacrificing the diversity of wheat resources and making the wheat germplasm resources single.The ancestral species of T.Urartu and Aegilops tauschii are the genomic donors of the heterologous hexaploid wheat A genome and D genome,respectively,which can provide a rich source of genetic variation for wheat breeding and excavate ancestral species.The introduction of superior genes into wheat can broaden the genetic basis of wheat and create more high-yield,high-resistance wheat varieties.The genomes of Urartu,Aegilops,and rice were successively sequenced,and the mapping of genetic maps and physical maps provided the basis for the comparative study of wheat ancestors and rice genomes.A comparative analysis of the genes of Urartu,Aegilops and rice can provide a deeper understanding of the similarities and differences between their genomes.Bioinformatics knowledge of gene annotation,gene structure and functional analysis of rice genome can be used for the genetic exploration of Urartu and Aegilops and excellent gene development,providing more alternative genetic resources for wheat molecular breeding and broadening wheat genetic diversity.In this study,the GC content of wheat ancestors and rice genomes were compared,SSR site mining and alignment analysis,homologous nucleotide sequence alignment and amino acid sequence alignment analysis,preliminary understanding of wheat ancestral genome and experiment The difference between rice genomes lays a foundation for further utilization of rice genome analysis of wheat ancestralIV species,mining of ancestral elite genes and improving wheat breeding efficiency.The experimental results are as follows:(1)Statistical analysis of GC content of genomes of whole genomes of Urartu,Aegilops,and rice showed that there was no significant difference in GC content among chromosomes in the same species because chromosomes passed in the same genetic background.Recombination,exchange,etc.,reached the equilibrium of the GC content of each chromosome.In different species,the difference in GC content is significant,indicating that if the GC content of the two unknown species is significantly different,it indicates that they are not the same species.Although Urartu and Aegilops belong to the same genus,there are significant differences in GC content.(2)SSR locus mining and analysis of the whole genome of Uraltu,Aegilops and rice,we found that there are differences in the types and proportions of SSR loci in the genome.Among the SSR types,the dinucleotide repeats are the most,the trinucleotide repeats,the hexanucleotide repeats are the second,and the tetra-and pentanucleotide repeats are the least.The types of major nucleotide repeats of different species are also different.The differences and diversity of SSR loci will allow us to better utilize SSR loci for marker development,providing technical support for locating important genes and cloning.(3)In the homologous nucleotide sequence alignment,678,656 sequences in the Urartu genome found homologous sequences in the rice genome,and 748,050 sequences in the crude Aegilops genome found homologous sequences in the rice genome.After screening more than 4000 bp homologous sequence analysis,it was found that the chromosome 3 matched the most homologous sequence in the rice genome(667),and the homologous sequence matched by the chromosome 5 in the rice genome in the Aegilops.Most(1532).Using mapchart mapping,it was found that the homologous sequences above 4000 bp were concentrated on the short arm of the Urartu,while the Aegilops was distributed on both the long arm and the short arm.The results of Circos mapping indicate that homologous nucleotidesequences at the same position in the Urartu and the Aegilops can find multiple homologous sequences in rice,and the homologous nucleotide sequences matched in rice will also be in the Urartu.Multiple homologous sequences were found in the Aegilops,indicating the replication of large fragment homologous sequences in all three species.(4)In the amino acid sequence alignment,the amino acid alignment of the Urartu and rice matched 3757 homologous amino acid sequences,and the matching rate was 6.57%.The amino acid sequences of Aegilops and rice were matched with 5,593 amino acid sequences,and the matching rate was11.33%.MCScan X mapping was performed on the matching results.Experiments showed that rice,Ural,and Aegilops have a high degree of overall collinearity.It is indicated that in the evolution of gramineous crops,many large fragments of genes are conserved,and the arrangement and order of many genes have not changed in the long-term evolution.This lays a theoretical foundation for us to use the relevant information in the rice genome for mapping and excavating related genes in Aegilops and Urartu.