| The Genus Iris L. is the largest and most evolutional genus in Iridaceae of monocotyledons. There are more than 300 species around the world and 60 species in China. It's distribution centers in the world. The wild plants of the genus Iris have high ornamental value. Both life force and resistance are strong at the same time they keep green for long time. And are very good view fallacious plant, having broad application prospect. But there were difficulties in the introduction and identification, leading to our taxonomy of the genus still exist many disputes. In view of the above mentioned reasons, on the basis of the works of our predecessors, we continue to study on a system of botanical classification and evolutionary botany two development directions, more recognition from the current two scholars Mathew and Rodionenko systematic of the genus Iris relations, trying to make a thorough and systematic study of molecular evolution on the Chinese Iris in China.With innovation of the research methods and means, the phylogenetic study of plant groups began to shift to micro-system characteristics, so that the classical taxonomy of the past in theory and methods experienced a change. Finding out genus evolved system of Iris will provide theoretic instruct and technical support for breeding, propagation as well as application in garden. For this purpose, we choose wild Iris taxa in 45 of 80 samples of typical plants for the study (China produced about 60 Iris,75% of its experimental species, represents one of six sub-genus and in addition to Sec. Lophiris under all the group). Analysis of four chloroplast genes (matK, trnL-trnF, rbcL and psbA-trnH) and one nuclear gene fragments (CHS) and known chromosome number of some species were selected. Combined with the main part of the genome sequence of chromosome number of studies, we give its subgenus Iris species and taxonomic groups for revision. The results as follows:(1) The four plastid gene segments and CHS nuclear genes joint analysis of fragments largely were seted to provide the phylogeny evidence of the genus Iris; the results of the 45 taxa sequenced show that we can divided into three major groups within the plant system by Subgenera Iris, Subgenera Limniris mainly.(2) The topological structure show that Subgenera Crossiris does not support as a single department, but there is still necessary to retain the systematic position and worth pursuing.(3) The chromosome number and genes of the evolutionary relationships obtaining show that the relationship of Subgenera Xyridon and Subgenera Pardanthopsis has very big change in main position. I.halophila should not be divided into Subgenera Xyridon, and as endemic to China I.subdichotom should adjust to Subgenera Nepalensis.(4) Comparing the two major subordinate classification systems, further establish and revise the classification system of Iris from China. And keep Subgenera Crossiris, the most complex types of the various Subgenera Limniris species under different groups upgrading to the group by discussion according to Mathew system of group.(5) The discussion and amendments of many contentious taxes were carried based on the experimental results; their classificatory position and belonging were discussed.
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