【作者】 高玉梅；

【导师】 孙日飞；

【作者基本信息】 中国农业科学院 ， 蔬菜遗传育种， 2009， 博士

【摘要】 白菜类作物(Brassica rapa)栽培历史悠久,遗传资源丰富,不仅是我国的重要蔬菜,还包括重要的油料作物。白菜类作物的分类、系统进化问题比较复杂,国内外的研究报道结果不尽一致。本研究对来自全国不同地理来源地63份白菜类作物种质资源进行染色体基因组DNA、叶绿体基因组和核糖体ITS序列等水平上的研究,探讨了白菜类作物的系统进化、分类等。获得的主要结论如下::1.对63份白菜类作物进行了形态观察,利用聚类分析的方法明显地分成为3个类群,并且可以很明显的看到类群的划分基本上和形态学性状的直接相关,与地理来源无关。Ⅰ类群包括两个亚类群,第1亚类群包括:1份紫菜苔材料、5份薹菜材料、1份日本小菘菜材料;第2亚类群由7份白菜型油菜材料、1份意大利菜心材料、1份普通白菜材料(郑州黑白菜)。Ⅱ类群包括13份普通白菜材料、3份菜心材料、2份早熟结球白菜材料、2份黄心乌材料、7份乌塌菜材料和5份芜菁材料。Ⅲ类群包括14份结球白菜材料和1份普通白菜材料。2.对芸薹属中白菜类作物的ITS序列进行研究,从63份白菜类作物中选取涵盖各种类型18份材料,对其ITS序列进行比对分析,构建NJ系统进化树。结果发现不同地理来源、不同类型的白菜类作物间的ITS序列高度保守,芸薹属种间存在明显变异。进一步研究发现芸薹属中的基本种内的变种间没有明显变异,复合种内的变种间有明显变异,分别倾向于U-trangle推测的父母本。3.选用126对引物,筛选出72对SSR标记和SRAP标记有清晰多态性条带的引物组合,扩增得到156条多态性条带,聚类分析将白菜类作物分为3大类群,类群I为不结球白菜聚,类群II为白菜型油菜、薹菜,类群III主要是大白菜。芜菁同时存在于类群II和类群III。群体结构分析证实白菜类作物资源存在3个组群,组群1和组群2间距离较近,其中组群3的遗传多样性更丰富。4.利用33对叶绿体基因组cpSSR标记引物组合对63份白菜类作物材料进行扩增,对白菜类作物的叶绿体基因组的遗传多样性进行研究,结果表明本实验中的63份各种类型的白菜类型间没有明显的差异条带,即各种类型的白菜类型间的叶绿体基因组没有遗传多样性,因此本实验中的材料叶绿体基因组是非常保守的。5.对6份白菜类作物的叶绿体基因组atpB-rbcL和trnL-trnF基因片段进行PCR扩增,产物为一条单一特异性条带,大小约为700bp大小。trnL-trnF序列在不同类型的白菜类作物间非常保守,atpB-rbcL序列在不同类型的白菜类作物间有明显的变异。对atpB-rbcL序列采用ClustalX、Bioedit和MEGA软件对序列构建系统进化树。从系统树上我们可以看到白菜类作物和邻近的属的植物明显分为两个分支,这一点和形态学方面的结果一致,因此atpB-rbcL间隔子序列可以作为分子标记分析白菜类作物的系统进化和分类。更多还原

【Abstract】 Brassica rapa L. has a long history of cultivation with vast genetic diversity. it is not only important vegetables, but also important oil crops. The classification and evolution of Brassica rapa are not very clear although some research have been done. In this research 63 accessions of Brassica rapa from different regions were used to study their phylogeny and classification by nuclear and chloroplast DNA analysis. The results are shown as follows:1. The characteristics of 63 accessions were use for clustering: all accessions are classified into 3 groups. The group I included two sub-groups, the first sub-group includes zicaitai, 5 taicai; the second sub-group included 7 Turnip rape, one Broccoletto, Pak choi(Zhengzhou black cabbage). GroupⅡincluded 13 Pak choi, 3 caixin, 2 Chinese cabbage, two Yellow heart cabbage ,7 Wuta-tsai, 5 turnip. GroupⅢincluded 14 Chinese cabbage and one Pak choi.2. The ITS of 18 different types of Brassica rapa L. were amplified by PCR and sequenced, and used to construct the NJ tree. The results showed that the sequences of the ITS of Brassica rapa L. had no variations among different types. That indicates that he sequences of ITS of Brassica rapa L. were very conservative. Among Brassicas, Brassica rapa L. is closer to B. napus, B.olereacea than to B. juncea, B. nigra. The relationship of the brassica species by the ITS sequences is as the same as shown by U-triangle.3. SSR and SRAP were used to the genetic diversity of 63 accessions of Brassica rapa L. Seventy two pairs of primers were selected. One hundred and fifty six polymorpsim bands were obtained. The results showed that cultivars of non-heading Chinese cabbage were clustered into Group I. turnip rapa and caitai were included in Group II. Heading Chinese cabbage was Group III. Turnips existed at Group II and Group III respectively. Three distinct gene pools exist among the accessions of Brassica rapa.4. Thirty three chloroplast genome cpSSR markers were amplified for the study of genetic diversity. The results showed that there was no polymorphic bands between 63 Brassica rapa accessions, namely the chloroplast genome was very conservative and had no genetic diversity by the SSR markers.5. The atpB-rbcL and the trnL-trnF gene spacers were amplified in 6 Brassica rapa accessions. Both of amplified bands were 700 bp approximately. TrnL-trnF sequence was not found differences among Brassica rapa accessions. AtpB-rbcL sequence had obvious variations among tested accessions. atpB-rbcL sequences were used to construct the phylogeny evolution tree. Brassica rapa, Brassica oleracea and Brassica napus were didvided into different branches. Brassica rapa accessions also were divided into two branches.更多还原