【作者】 倪念春；

【导师】 许介眉；

【作者基本信息】 四川大学 ， 植物学， 2002， 硕士

【摘要】 粗根组(Sect.Bromatorrhiza Ekberg)隶属于广义百合科(Liliaceae s.J.)葱属(Allium L.)，有10种3变种，为东亚特有。全部种类集中分布于我国西南部，主产横断山区。仅4个种的分布区扩大到与我国西藏和云南比邻的周边国家。本文研究了该组8种1变种，包含该组所有染色体基数类型，材料来自四川、云南两地。 (1)首次对峨眉韭A.omeiense Z.Y.Zhu、灌县韭A.guanxianense J.M.Xu、木里韭A.hookeri Thwaites var.muliense Airy-Shaw、杯花韭A.cyathophorum Bur.&Franch.、粗根韭A.fasciculatum Rendle、三柱韭A.trifurcatum(Wang et Tang)J.M.Xu的ITS基因进行了序列测定。另对Genebank中已有的宽叶韭A.hookeriThwaites、多星韭A.wallichii Kunth、大花韭A.macranthum Baker以及外类群韭A.tuberosum Rottl.．ex Spreng.、山韭A.senescens L.的ITS基因进行了序列测定。各种类ITS基因长度为：峨眉韭679bp、灌县韭701bp、木里韭670bp、杯花韭612bp、粗根韭666bp、三柱韭666bp、宽叶韭680bp、多星韭649bp、大花韭666bp、韭644bp、山韭643bp。 (2)利用系统发育分析软件PAUP4.0β8和MEGA2.0对粗根组种类进行了分子系统树重建。采用邻接法(neighbor joining method)、非加权配对算术平均法(UPGMA)、最大简约法(most parsirnony method)、最小进化法(mininmm evolutionmethod)和最大似然法(maximum likelihood method)，通过定义和不定义外类群，以及选择不同数量的外类群对所得的序列数据进行分析，重建了分子系统树。结果表明：①杯花韭应从粗根组中划出；②三柱韭应从粗根组中划出；③基数为11的粗根组种类为一单系群；④基数为10的粗根韭与基数为11的粗根组种类具有 密切的余缘关系；⑤基救为7的多呈韭与大花韭具有不同的进化途径，亲缘关系 较远：③粗地组成员的合理组成应为基数为11的种类，外加基数为10的粗恨韭 和基救为7的多丑韭与大花＿Ik。 （3）对分析软件与分析方法进行了简单比较。 宽叶韭隶属于葱属粗根组，分布于四川、云南西北部和西臧东南部。生】y＃ 拔 1500叶000m的湿润山坡或林下。斯军兰卡、不丹和印度的北部也有分hi，在 我国南力‘的一些地区栽培作蔬菜食用。 本文应用随机扩增多态0＊以RA Pm技术，对宽叶韭的11个居群进行了种内 分化研究。实验所得的 RAPD资料利用 RAPDistance package＊4软件、MEGA 2刀软件、PAUP4．田 8软件，采用多种运算系数和构树方法进行聚类分析，得到 近乎完全相同的聚类结果，显示宽叶韭为一单系群，支持宽叶韭种的成立。彻汁 韭明显分为两大分支，这与宽叶韭的冬季倒茵和冬季不倒苗的两种生活习性亢全 一致，与宽叶韭的倍性和生境（海拔）密切相关。RAPD研究结果与细胞学研究、 植物化学研究和生物化学的研究结果基本一致，表明宽叶韭内的确存在着明显的 种内分化现象，而多倍化可能为宽叶韭进化的趋势。更多还原

【Abstract】 Sect. Bromatorrhiza Ekberg belongs to Allium L. (Liliaceae s.l.). Traditionally, there were 10 species and 3 variants in sect. Bromatorrhiza. It only distributed in the east area of Asia and most species of the section clustered in the southwest area of China, prospering in Hengduan Mountains. Only 4 species in this section were spread to neighboring country that bordered with Tibet or Yunnan province. 8 species and 1 variants collected from Sichuan and Yunnan were studied in this paper. The materials comprised all kinds of chromosome basic numbers.(l)The ITS of nrDNA gene was amplified by PCR method and the PCR product was directly sequenced. A. omeiense Z.Y.Zhu 679bp, A. guanxianense J.M.Xu 701bp, A. hookerii Thwaites var. muliense Airy-Shaw 670bp% A. cyathophorum Bur. & Franch. 612bp, A. fasciculatum Rendle 666bp, A. trifurcatum (Wang et Tang) J.M.Xu 666bp were reported here for the first time. A. hookeri Thwaites 680bp, A. wallichi Kunth 649bp, A. macranthum Baker 666bp, A. tuberosum Rottl. ex Sprang. 644bp, A. senescem L. 643bp.(2)The sequences of ITS gene were applied to reconstruct molecular phylogenetic tree based on neighbor joining, UPGMA, minimum evolution, most parsimony and maximum likelihood methods, with or without defined outgroups or different numbers of outgroups respectively by PAUP and MEGA. The results indicated the following: (1)A. cyathophorum ought to be kicked out from sect. Bromatorrhiza; (2)A. trifurcatum ought to be kicked out from this sect; (3) amonophyletic group of X=11 species was shown in the ITS tree; (4)A. fasciculatum had a close relationship with X=11 species; (5)A. wallichii and A. macranthum had different evolution processes, their relationship was not so related; (6)the sensible components of sect. Bromatorrhiza should comprise X=11 species and A. fusciculalum (X=10). A. wallichi and A. macranthum (X=7).(3)Comparing the different analysis softwares and different analytic approaches.In present paper, random amplified polymorphic DNA (RAPD) phenotypes generated by 7 primers were scored in 11 populations of Allium hookeri. A series of computing indexes were applied to obtain genetic distance matrixes. NJ tree. UPGMA tree. ME tree. MP tree and ML tree were produced by RAPDistance package 1.04, MEGA 2.0 and PAUP 4.0?8 software package. All the trees were nearly same to each other. The results showed that A. hookeri was a monophyletic group which supported the existence of species of A. hookeri and all the populations of A. hookeri were divided into two groups which were identical with the habitus of withering in the winter and not withering in the winter and highly related to ploidy and habitat (altitude). The results are basically comparable with those obtained from studies on morphology, cytology, biochemistry and phytochemistry. A significant intraspecific differentiation among the populations of A. hookeri was confirmed by the use of RAPD analysis. Differentiation level of not withering in the winter populations is higher than that of withering in the winter ones.更多还原