Phylogenetic analysis of wheat and its relatives based on the nucleotide sequence of rbcS.

摘要

In order to reveal the evolutionary process of wheat polyploidization, I investigated the nucleotide variation of the rbcS gene in 11 wheat and wheat-related species. Phylogenetic analysis indicated that, among the five Sitopsis species, Aegilops speltoides is the most likely candidate donor of wheat B and G genomes, and that two tetraploid wheat species have a diphyletic origin. The results of Tajima's relative rate test showed that evolutionary rate has not changed among the genomes in polyploids,suggesting that polyploidization did not release the selective pressure for this gene.