环太湖野生菰种质资源调查及遗传多样性分析

发布时间：2018-09-07 06:38

【摘要】：太湖为中国第三大淡水湖,生态功能价值巨大。菰(Zizania latifolia)为多年生宿根草本挺水观赏植物,禾本科菰属,稻亚科,稻族,菰喜温暖,喜阳光,菰与水稻是近缘属。菰在中国存在的历史悠久,最早记录可以追溯到3000年前的周代。菰具有优良的生态价值、观赏价值、食用价值、药用价值。菰属(Zizania L.)植物分为4种,分别是菰、水生菰、沼生菰、德克萨斯菰(又称流水菰)。菰主要分布在亚洲东部、东南亚和中南半岛地区,水生菰、沼生菰、德克萨斯菰主要分布在北美的美国、墨西哥、加拿大,欧洲地区也有分布,其中分布在美国的圣马克斯河岸的德克萨斯菰濒临灭绝。目前还未见太湖野生菰种质资源遗传多样性研究,此次太湖40个野生菰居群遗传多样性研究,意义在于为今后野生菰种质资源的调查、收集、保护、开发、利用、推广提供依据,以达到保护物种多样性,保护生态环境的目的,从而保护太湖生物多样性,维护生态平衡。同时为野生菰优良基因开发和利用、遗传进化研究提供依据。主要研究结果如下:(1)太湖地区野生菰分布广泛,生长能力强,但随着人类的开发建设及不合理开发利用,野生菰的数量正逐年减少。从调查的40个样点来看,生长在太湖的样点有18个,占比45%,其余22个样点野生菰均发现于距太湖湖岸3 km~5 km的小河、水沟或湿地。18个样点大多分布在太湖南侧的湖州和吴江市,太湖西侧南部大约25 km距离的河岸人为硬化,无菰植物生长。(2)从表观数据进行遗传多样性分析得出,太湖野生菰6个表观性状的平均变异系数为33.02%,变化幅度为18.34%~52.22%。进一步对太湖野生菰40个群落表观性状变异系数平均值分析得出,9个野生菰群落变异系数平均值在20%以上,22个居群变异系数平均值在10%~20%之间,10%以上的居群占比78%。同时从叶面形态上对太湖野生菰40个居群进行聚类分析,共分为四大类,其中两类叶面形态特征较突出,表观数据分析得出太湖野生菰遗传变异大,遗传多样性水平高,太湖西侧北部、太湖北侧及太湖东南侧、南侧相比其他方位菰遗传变异程度高。(3)通过SSR分子标记技术,对太湖野生菰40个群落88个样本进行了种质资源遗传多样性及遗传结构研究分析。经过筛选的19对SSR标记共扩增出条带113条,其中多态性条带111条,多态性百分比98.23%,居群间基因多样性指数(He)为0.2763,信息指数(I)为0.4288;遗传距离(GS)在0.0681~0.8224之间,遗传相似性系数(GS)在0.4394~0.9342之间;采用UPGMA法对40个居群进行聚类分析,阈值为0.195时,将40个居群分为11类;居群间和居群内显著性检测显示P0.01,说明差异极显著,居群的遗传结构差异大。通过遗传变异性强弱和遗传结构差异大小表明,太湖地区野生菰居群间SSR基因型的多样性丰富,遗传多样性水平高,从太湖地区不同方位群落发生显著变异出现的频率和数量来看,大致可以将太湖地区野生菰种质资源遗传多样性水平高低排序为:西侧北半边、北部东南、南部东部、东北。
[Abstract]:Taihu Lake is the third largest freshwater lake in China and has great ecological value. Zizania latifolia is a perennial perennial perennial herbaceous ornamental plant. Zizania latifolia belongs to the genus of gramineae, rice subfamily, rice family. It likes warmth and sunshine. Zizania latifolia is closely related to rice. Zizania latifolia has a long history in China and the earliest record can be traced back to the Zhou Dynasty 3000 years ago. Zizania L. (Zizania L.) plants are divided into four species, namely, water chestnut, aquatic chestnut, bog chestnut, Texas chestnut (also known as flowing water chestnut). The chestnut is mainly distributed in eastern Asia, Southeast Asia and the peninsula of central and southern China, aquatic chestnut, bog chestnut, Texas chestnut mainly distributed in North America, Mexico, Mexico, Texas. There is no study on genetic diversity of wild water chestnut germplasm resources in Lake Taihu. The study on genetic diversity of 40 wild water chestnut populations in Lake Taihu is significant for the future investigation, collection, protection and development of wild water chestnut germplasm resources. The main results are as follows: (1) Wild Chinese chestnut is widely distributed in Taihu Lake area, and has strong growth ability, but with the development and utilization of wild Chinese chestnut genes, genetic evolution research provides the basis. The number of wild Chinese chestnuts is decreasing year by year with the development, construction and unreasonable utilization of human beings. According to the 40 sampling sites surveyed, 18 of them grow in Taihu Lake, accounting for 45%. The remaining 22 samples are found in small rivers, ditches or wetlands 3 km to 5 km away from the shore of Taihu Lake. (2) Genetic diversity analysis showed that the average variation coefficients of six apparent characters of wild Chinese chestnut in Taihu Lake ranged from 33.02% to 18.34%-52.22%. Furthermore, the average variation coefficients of the six apparent characters of wild Chinese chestnut communities in Taihu Lake were analyzed. The results showed that the average variation coefficients of 9 Wild Chinese chestnut communities were above 20%, the average variation coefficients of 22 populations were between 10% and 20%, and the proportion of over 10% was 78%. The genetic variability of wild Chinese chestnut in Taihu Lake was large and the genetic diversity level was high. The genetic diversity and genetic structure of 88 samples of wild Chinese chestnut communities in Taihu Lake were studied by SSR markers. A total of 113 bands were amplified from 19 pairs of SSR markers, including 111 polymorphic bands, 98.23% polymorphic percentage, 0.2763 genetic diversity index (He), 0.4288 information index (I), 0.0681-0.8224 genetic distance (GS) and 0.4394-0.9342 genetic similarity coefficient (GS); 40 populations were clustered by UPGMA. When the threshold value was 0.195, the 40 populations were divided into 11 groups. Significance test between and within populations showed P 0.01, indicating that the difference was extremely significant and the genetic structure of the population was very different. According to the frequency and number of significant community variation in different directions in Taihu Lake area, the genetic diversity level of wild Chinese chestnut germplasm resources in Taihu Lake area can be roughly sorted as follows: the northern half of the west, the southeast of the north, the east of the South and the northeast.
【学位授予单位】：江西财经大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S645.2

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