银杏古树半同胞家系变异规律及株高生长基因筛选

发布时间：2018-10-29 22:45

【摘要】：银杏是珍贵的经济树种,果、叶、材等用途广泛,有着较高的经济价值,银杏是裸子植物中古老的孑遗植物,有极其重要的理论价值。我国银杏古树资源较为丰富,但受环境变化等诸多因素影响,正在逐渐减少,因而对银杏古树进行保护与利用,显得尤为紧迫。目前,国内部分地区已经开展了对其本地银杏半同胞家系的研究,且多为家系形态指标研究,对全国范围内收集银杏种实并进行半同胞家系研究未见报道。本研究在全国范围内收集98个县市130株银杏古树种实,播种育苗后构建银杏半同胞家系种质资源圃,随后对银杏半同胞家系进行生长指标测定、核型分析,AFLP分子标记研究。本研究分别从生长量、细胞水平、分子水平对银杏半同胞家系进行变异规律分析,并初步评价出苗期生长优良的半同胞家系;根据银杏古树种实形态特性,分析银杏古树种子分布规律,为进一步的银杏良种评价提供参考。此外,本研究利用BSR技术对银杏半同胞家系进行高通量测序,发掘与株高生长性状相关的基因,为后续开展功能基因研究和分子育种实践提供有价值信息,以及为遗传连锁图谱构建,生长性状主效QTL的精确定位等研究提供有力工具。本研究的主要结果如下:(1)根据银杏半同胞家系连续三年的生长量,初步选择出72 (广西兴安)等优良银杏半同胞家系8个。根据银杏半同胞家系遗传多样性结果可知,银杏半同胞家系北部区、西部和南区遗传多样性高于中部区和东部区家系。此外,28个银杏半同胞家系核型分析表明,银杏从贵州、四川地区向西南及东北方向进化。因此,根据银杏的进化趋势及遗传多样性分析,最终选出北部区、东部区、西部区和南部区优良银杏半同胞家系各2-3个。(2)本研究采用的8对AFLP引物对297份银杏半同胞家系进行扩增,检测到谱带1727条,均为多态带;8对引物中仅有4对引物有单态带,由此可见,银杏半同胞家系表现了较高的多态性水平。由Gst估算的银杏半同胞家系基因流值Nm为1.4085,表明银杏半同胞家系间存在一定程度的基因交流,但家系间的基因流明显处于较低水平。(3)根据银杏种实形态的差异,本研究将古树种子分布地点划分为5个区域:东部区、中部区、北部区、南部区和西部区。根据种子营养成分分析可知,不同古树种子营养成分与地理区域关系不显著。东部区种子主要分布于山东、江苏、浙江三省,该区古树种实相对较大,可重点进行核用银杏良种选育。(4)本研究用BSR技术对贵州盘县银杏半同胞家系高生长株和矮生长株两个混池进行转录组测序,识别差异表达基因601个,其中有513个基因得到功能注释。对高生长株和低生长株两个样本的reads进行SNP分析,BSR关联到119个基因,其中58个基因得到功能注释。
[Abstract]:Ginkgo biloba is a precious economic tree species, fruit, leaf, wood and other widely used, has a higher economic value, ginkgo biloba is an ancient relict plant in gymnosperms, has extremely important theoretical value. The ancient ginkgo tree resources are abundant in China, but due to the environmental change and many other factors, they are gradually decreasing, so it is particularly urgent to protect and utilize the ancient ginkgo trees. At present, some local Ginkgo biloba half-sibling families have been studied in some parts of our country, and most of them are family morphological indexes. No report has been reported on the collection of ginkgo seeds and half-sib families in the whole country. In this study, 130 ancient ginkgo trees were collected from 98 counties and cities in China. After seeding and seedling raising, the germplasm resource nursery of Ginkgo biloba half-sib family was constructed, and then the growth index, karyotype analysis and AFLP molecular marker study were carried out on Ginkgo Half-sib families. In this study, the variation rules of Ginkgo biloba half-sib families were analyzed in terms of growth, cell level and molecular level, and preliminary evaluation of half-sib families with good growth at seedling stage was carried out. According to the seed morphological characteristics of ancient ginkgo trees, the seed distribution of ancient ginkgo trees is analyzed, which provides a reference for further evaluation of improved ginkgo varieties. In addition, the high throughput sequencing of Ginkgo biloba semi-sib families was carried out by using BSR technique, and the genes related to plant height growth traits were discovered, which provided valuable information for further functional gene research and molecular breeding practice. It also provides powerful tools for the construction of genetic linkage map and the precise mapping of QTL for growth traits. The main results of this study are as follows: (1) according to the growth of Ginkgo Half-sib families for three consecutive years, 8 excellent Ginkgo Half-sib families 72 (Xingan, Guangxi) were preliminarily selected. According to the genetic diversity of Ginkgo biloba half-sib families, the genetic diversity of Ginkgo biloba half-sib families in the northern, western and southern regions was higher than that in the central and eastern regions. In addition, the karyotype analysis of 28 semi-sib families of Ginkgo biloba showed that Ginkgo biloba evolved from Guizhou and Sichuan to southwest and northeast. Therefore, according to the evolutionary trend and genetic diversity analysis of Ginkgo biloba, the northern and eastern regions were selected. There were 2-3 excellent Ginkgo biloba half-sib families in the western and southern regions. (2) eight pairs of AFLP primers were used to amplify 297Ginkgo biloba half-sib families and 1727 bands were detected, all of which were polymorphic. There were only 4 pairs of primers with monomorphic bands in 8 pairs of primers. It can be seen that Ginkgo biloba semi-sib families showed a high level of polymorphism. The Nm estimated by Gst was 1.4085, which indicated that there was a certain degree of gene exchange among the half-sib families of Ginkgo biloba, but the gene flow among families was obviously at a lower level. (3) according to the differences of seed morphology of Ginkgo biloba. In this study, the seed distribution sites of ancient trees were divided into five regions: eastern region, central region, northern region, southern region and western region. According to the analysis of seed nutrient composition, there was no significant relationship between the nutritional composition and geographical region of different ancient trees. Seeds in the eastern region are mainly distributed in Shandong, Jiangsu and Zhejiang provinces, where ancient tree species are relatively large. (4) in this study, BSR technique was used to sequence the two mixed pools of high and low growth plants of Ginkgo biloba Half-sib families in Panxian, Guizhou Province, and 601 differentially expressed genes were identified. Of these, 513 genes were annotated. The reads of two samples of high and low growth plants was analyzed by SNP. The BSR was associated with 119 genes, of which 58 genes were annotated.
【学位授予单位】：山东农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S792.95

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