Genetic And Epigenetic Changes Induced By Interspecific Hybridization In Oryza

Interspecific hybridization is an important mechanism of speciation,interspecific hybridization and the polyploidization exist widely in the plant evolution,and flowering plants experience polyploidyization.Interspecific hybridization happened frequently in higher plant,so interspecific hybridizationplays an important role of driving force in the formation of new species and evolutionary process.Interspecific hybridization and polyploidyization can promote the formation of new species and evolutionary process.The combination of divergent genomes within a hybrid can result in profound changes to both genome and transcriptome.Changes might happen in genomic instability,such as chromosomal rearrangements,transposon activation and rapid sequence elimination.And the changes also might include genes expression level,metylation pattern,alternative splicing changes and small RNAs.Three sets of hybrid varieties were successfully achieved by interspecific hybridization of rice,and a large group of phenotypic changes were found.By using molecular biology techniques including GISH,AFLP,MSAP,TD and TMD,three materials for genetic and epigenetic modification of genes were discovered.The results showed that interspecific hybridization of rice caused the the genome sequence variations along with a range of methylation patterns changed,meanwhile promoted a transposon activation of Dasheng.Besides,hypomethalytion in LTR region of 5' was also detected.The thesis tries to reveal the molecular mechanism of mutations in hybrids,uncover the influence on the genetic and epigenetic stability of hybrids and reveal the important role in rice evolution from the interspecific hybridization.