| The 39 populations of 23 Iris species were collected from Yunnan, Jilin, Heilongjiang, Gansu, Xinjiang, Ningxia, Jiangsu, Shandong, Hebei and Beijing. By the analysis of morphological traits, Amplified Fragment Length Polymorphism (AFLP) and chloroplast DNA (cpDNA) trnF-trnL sequence, their genetic diversity and distributions were conducted, and their systematic positions were studied. The main results were as follows. (1) Among the 18 phenotypic traits of leaves, flowers, fruits and seeds in Iris, leaf length, leaf width, flower diameter, flower height, fall length, fall width, standard length, standard width, weed length and weed width were the important traits. Besides, the traits of flowers and seeds were prior to the others. The great varieties of leaf length and leaf length-to-width ratio accorded with the classical researches. The phenotypic variation coefficient (Vst) of morphological traits ranged from 37.30% to 96.77%. The mean variance components among and within species were respectively 69.03% and 20.36%. All these suggested that there were rich diversities among/ within species. The phenotypic clustering showed that as an unnatural taxon, Subgen. Limniris was divided into several subgenera, and a part of the Subgen. Crossiris existed as a subgenus, and the other and Subgen. Xyridion were added to Subgen. Limniris. Subgen. Paranthopsis and Subgen. Nepalensis as two subgenera were confirmed. Besides, most different resources of the same species, such as I. lactea, I. bulleyana, I. pseudacorus, I. collettii and I. tectorum, were closely related and gathered together. (2) In the 26 samples of Iris, 6 EcoRI-MseI AFLP primer combinations revealed 872 legible bands, of which there were 25 specific bands and no common bands. The UPGMA dendrogram indicated that I. tigridia and I. mandshurica were included in the different subsections or subgenera. And Subgen. Paranthopsis and Subgen. Nepalensis as two subgenera were confirmed. Subgen. Crossiris was divided into several subgenera. Subgen. Xyridion was included into Subgen. Limniris or taken as a subgenus sister to the subgenera separated from Subgen. Limniris. In the 10 samples of I. lactea, 1164 legible bands were obtained by using 18 primer combinations. The proportion of polymorphic markers was 65.11%. As the molecular markers of recognizing these plants, the common or specific bands were found in all the samples of I. lactea. It indicated that I. lactea might not be monophyletic and had geography variability. I. lactea from Xinjiang and Neimenggu province were closely related and belonged to one original branch, those of Minqin, Wuwei, Beijing and Taishan belonged to one branch. I. lactea of Changchun sister to that of Zhuozhou belonged to another branch. (3) The intergenic region of trnL and trnF was amplified by PCR for 24 samples of Iris. The lengths of the segments varied from 1003bp to 1113bp, of which 954bp was compared. The number of the evolutionary loci was 106, including 92 transpositional loci and 14 missing ones. The cpDNA results on taxa were consistent with that of AFLP marker. I. sanguinea was separated from Subgen. Limniris. And I. foetidissima and I. proantha were regarded as two subgenera. The trnL-trnF sequences of I. lactea of 9 populations were discussed. In the 6 samples of I. lactea from Beijing, Minqin, Guyuan, Taishan, Wuwei and Zhuozhou, there were 2 transpositional loci and 1 missing ones, which was 0.35% of the compared lengths. With 5 information loci, the sequences of 3 samples from Taipu, Xiwuqi and Wulumuqi were homologous by a percent of 99.64. It also showed I. lactea might not be monophyletic. The difference was that I. lactea of Changchun and Zhuozhou belonged to the Beijing branch by cpDNA marker. In summary, the quantitive criteria for genetic resources collection and conservation, genetic diversity evaluation and utilization of Iris had been provided. At the same time, it helped to the correlative research of the genus sister to Iris.
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