高粱粒重的QTL分析及qGW1的精细定位

发布时间：2018-12-16 06:06

【摘要】：高粱是人类最早栽培的重要谷类作物之一,具有用途广泛,抗逆性强,种植范围广等特性,是有广阔应用前景的能源和粮食作物。随着世界人口的不断增长、可耕地面积的不断减少以及水资源的严重短缺,种植并培育高产的高粱品种将对世界粮食安全问题产生深远影响。目前,利用常规育种方法来增加高粱的产量已变得非常有限,而基于生物技术或基因工程的分子育种手段将能有效增加高粱的产量。粒重是构成产量的一个重要因素,发掘控制高粱粒重的基因并阐明其调控机理是开展高粱高产分子育种的前提,因此,对高粱粒重进行QTL分析并对主效QTL进行精细定位将具有重要的理论意义和应用价值。而转基因育种是进行分子育种的一种有效手段并且转基因方法也是进行相关基因功能验证的重要方法,因此,建立一套高粱成熟胚的高效转基因体系具有重要意义。本研究利用大粒高粱品种SA2313与小粒高粱品种Hiro-1杂交构建的定位群体对高粱粒重进行了QTL分析并对主效QTL进行了精细定位,同时利用Hiro-1的成熟种子为外植体构建了一套高效转基因体系,主要研究结果如下：1.利用SA2313×Hiro-1杂交得到的F2群体对高粱粒重进行QTL分析,共检测到7个控制高粱粒重的QTL,它们所解释的表型变异率介于7%～40%之间。这7个QTL均与前人的定位结果相同,没有新定位到的QTL。2.利用种于北京和海南两地的SA2313×Hiro-1 F2群体能够重复检测到两个控制高粱粒重的QTL, qGWl和qGW2,其所解释的表型变异率分别介于22%～40%之间和13%～27%之间,是控制高粱粒重的主效QTL3.利用K-385×SA23、ATx623×SA2313杂交得到的两个F2群体对高粱粒重主效QTL进行检测,只有qGWl均能够被检测到,说明qGW1在不同的遗传背景下能够稳定存在。4.利用SA2313×Hiro-1 F3群体中的极端交换单株,将qGW1精细定位到1号染色体短臂大约101 kb的范围内,包含13个候选基因。测序发现只有Sobic.001G038300基因在四个亲本中编码氨基酸的变异与表型变异是一致的,因此初步确定其为qGW1的候选基因,仍需进一步验证。5.构建了qGWl的近等基因系,为qGWl的进一步精细定位提供了有力的作图群体。6.利用Hiro-1的成熟种子为外植体构建了一套高粱高效的转基因体系,平均转化效率为12.31%,为高粱重要基因的功能验证及高粱分子育种提供了重要基础。以上研究结果对阐明高粱粒重的遗传机理提供了重要信息,与qGWl紧密连锁的分子标记可以用于高粱高产育种的分子标记辅助选择,并且qGWl的精细定位为qGW1基因的克隆及进一步明确其调控机理提供了重要依据。
[Abstract]:Sorghum is one of the most important cereal crops cultivated by human being, which has the characteristics of wide use, strong resistance to stress and wide planting range. Sorghum is a kind of energy and food crops with broad application prospects. With the increasing of world population, the continuous decrease of arable land area and the serious shortage of water resources, the cultivation and cultivation of high-yielding sorghum varieties will have a profound impact on world food security. At present, using conventional breeding methods to increase the yield of sorghum has become very limited, and molecular breeding methods based on biotechnology or genetic engineering can effectively increase the yield of sorghum. Grain weight is an important factor that constitutes yield. It is a prerequisite to develop molecular breeding for high yield sorghum to explore the genes controlling grain weight and clarify its regulation mechanism. QTL analysis of sorghum grain weight and fine location of main effect QTL will have important theoretical significance and application value. Transgenic breeding is an effective method for molecular breeding, and transgenic method is also an important method for functional verification of related genes. Therefore, it is of great significance to establish a set of efficient transgenic system of sorghum mature embryo. In this study, using the locational population constructed by hybridization of large grain sorghum (SA2313) and small grain sorghum (Hiro-1), the grain weight of sorghum was analyzed by QTL and the main effect QTL was carefully mapped. At the same time, the mature seeds of Hiro-1 were used as explants to construct a set of efficient transgenic system. The main results were as follows: 1. Using QTL analysis of grain weight of sorghum in F2 population obtained by SA2313 脳 Hiro-1 hybridization, a total of 7 QTL, controlling sorghum grain weight were detected. The rate of phenotypic variation explained by them was between 7% and 40%. The results of these seven QTL are the same as those of previous ones, and there is no newly located QTL.2.. Using the SA2313 脳 Hiro-1 F2 populations in Beijing and Hainan, the phenotypic variation rates explained by QTL, qGWl and qGW2, which control the grain weight of sorghum, ranged from 22% to 40% and 13% to 27%, respectively. Main effect QTL3. for controlling grain weight of sorghum Two F2 populations with K-385 脳 SA23,ATx623 脳 SA2313 hybridization were used to detect the main effect QTL of sorghum grain weight, only qGWl could be detected, which indicated that qGW1 could exist stably in different genetic background. 4. Using the extreme exchange single plant in the SA2313 脳 Hiro-1 F3 population, the qGW1 was finely mapped to the short arm of chromosome 1 about 101 kb, containing 13 candidate genes. It was found that only the variation of amino acids encoded by Sobic.001G038300 gene in the four parents was consistent with the phenotypic variation. Therefore, the preliminary identification of Sobic.001G038300 gene as a candidate gene of qGW1 still needs to be further verified. The near-isogenic lines of qGWl were constructed, which provided a powerful mapping population for the further fine mapping of qGWl. 6. 6. An efficient transgenic system of sorghum was constructed by using mature seeds of Hiro-1 as explants. The average transformation efficiency was 12.31, which provided an important basis for functional verification of important genes of sorghum and molecular breeding of sorghum. The above results provide important information for elucidating the genetic mechanism of sorghum grain weight. Molecular markers closely linked to qGWl can be used for molecular marker-assisted selection in sorghum breeding for high yield. The fine mapping of qGWl provides an important basis for the cloning of qGW1 gene and further understanding of its regulatory mechanism.
【学位授予单位】：中国农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S511

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