【作者】 牟少华；

【导师】 彭镇华； 孙振元；

【作者基本信息】 中国林业科学研究院 ， 林木遗传育种， 2005， 博士

【摘要】 本研究从云南、吉林、黑龙江、甘肃、新疆、宁夏、江苏、山东、河北和北京等部分省区收集了23 个种39 个种源的鸢尾属植物,采用表型分析、AFLP 分子标记和叶绿体DNA trnF-trnL 序列分析三种实验手段,研究了它们的遗传差异与分布状态,从表型和分子水平上揭示了它们的亲缘关系和系统位置关系。主要研究结果如下: (1)对鸢尾属植物叶片、花、果实和种子的18 个表型性状的研究表明,叶长、叶宽、花径、花高、垂瓣长、垂瓣宽、旗瓣宽、旗瓣长、种子长和种子宽是表型测定中的重要性状。其中,花和种子的这些性状较其它性状的稳定性高,是植物评价中应优先选用的性状。叶长、叶长宽比变化较大,符合经典研究规律。表型分化系数(VST)的变异幅度为37.30~96.77%,种间和种内的方差分量平均值分别为69.03%和20.36%,表明鸢尾属植物存在着丰富的种间和种内变异。表型聚类结果表明,无须毛附属物鸢尾分类群、鸡冠状附属物鸢尾分类群和琴瓣鸢尾分类群都是不自然的分类群,应将无附属物类群分成几个组或分类群,将鸡冠状附属物分类群一部分作为分类群的分类地位存在,另一部分和琴瓣鸢尾分类群一起都归入无须毛附属物分类群中。支持野鸢尾分类群和尼泊尔鸢尾分类群作为分类群的分类地位存在。另外,马蔺、西南鸢尾、黄菖蒲、高原鸢尾和鸢尾等同种不同种源的样品被首先聚在一起,亲缘关系密切。(2)运用6 对引物对鸢尾属植物的26 个样品基因组进行了AFLP 标记,共获得536条清晰的谱带,其中25 条为特异性带,缺少共有的谱带。UPGMA 聚类图表明,须毛状附属物分类群果实侧裂组中的粗根鸢尾和长白鸢尾应划分到不同的亚组或分类群中。支持野鸢尾分类群和尼泊尔鸢尾分类群作为分类群的分类地位存在。鸡冠状附属物分类群应分成几个分类群。琴瓣鸢尾分类群应置于无附属物分类群中或者作为一个独立的分类群,与无附属物分类群分成的几个分类群地位并列。运用18 对引物对10 个种源的马蔺样品进行AFLP 标记,共获得1164 条清晰的谱带,其中多态性带占总带数的65.11%。不同种源的马蔺都有特异性带或缺失条带,这些可以作为识别马蔺的标记。聚类分析表明,马蔺物种不是单系起源的,它的分化具有更多还原

【Abstract】 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.更多还原