【作者】 刘凯；

【导师】 常成；

【作者基本信息】 安徽农业大学 ， 作物遗传育种， 2018， 硕士

【摘要】 提高小麦产量是小麦育种工作的重要的目标之一。倒伏是限制小麦产量提高的主要因素之一,而茎秆强度是衡量倒伏抗性的重要指标,因此鉴定小麦茎秆强度的主要位点,并开发与其紧密连锁的分子标记,有助于小麦抗倒伏分子标记辅助选择育种。本研究利用遗传背景差异较大的105份小麦品种资源组成的自然群体,于2014、2015和2016三年连续测定茎杆强度,结合369个SSR标记基因型进行关联分析,初步定位控制小麦茎秆强度相关位点。然后,利用安农0711/河农825RILs群体（F₆,362份家系）验证其中5A和3B染色体上的主要位点对茎秆强度/倒伏抗性的效应,进一步基于小麦660K SNP芯片,开发CAPS标记,进一步证实上述5A染色体上主要位点的稳定性和表型效应。研究结果可以为精细定位抗倒伏位点以及挖掘候选基因奠定基础,同时为研究小麦抗倒伏遗传机理提供参考。主要研究如下:（1）对105份小麦品种资源组成的自然群体进行三年（2014、2015和2016）的茎秆强度表型测定,相关性分析结果表明,三年茎秆强度之间呈极显著正相关（P<0.01）,说明茎秆强度在环境间具有较好的稳定性。（2）将上述自然群体的SSR标记基因型与茎秆强度表型值进行全基因组关联分析,共检测到53个SSR标记与小麦茎秆强度显著相关,主要分布在1D、3A、3B、4B、5A、6D染色体上;两年及两年以上被检测到与茎杆强度显著相关的SSR标记共13个,分别位于染色体4BL（barc1096、barc199和gwm495）、7BL（barc176）、3BS（barc268）、3AL（barc314）、4AL（barc343）、3DS（cfd152）、6DL（cfd37）、6AS（gwm459）、2BS（wmc154）、1D/2A（wmc179）、4BS（wmc413）;在三种环境下与茎杆强度均显著相关的标记有3个,分别为barc1096（4BL）、barc314（3AL）、barc268（3BS）。（3）以安农0711/河农825 RILs群体（F₆,362个家系）为材料,利用在5A和3B上共筛选出的39个多态性SSR标记,通过连锁分析将5A（Qssahau-5A）和3B（Qssahau-3B）分别定位于gwm443-gwm156和barc358-wmc615之间,分别解释3.02%-3.20%和2.42%-3.38%的表型变异。（4）利用小麦660K SNP芯片扫描安农0711/河农825群体的两个亲本及高低池,基于5A染色体上目标区间差异的SNP信息,开发两个CAPS标记X-109445097（28.28Mb）和AX-95200348（445.27Mb）,其中AX-109445097与Qssahau-5A紧密连锁。更多还原

【Abstract】 Increasing yield is one of the important goals of wheat breeding.Lodging is one of the main factor that decreases wheat yield.Stem strength is an important indicator of lodging resistance,therefore,it is helpful for MAS to identify the major loci for stem strength and develop molecular markers closely linked with the major loci.In this study,we used a natural population consisted of 105 wheat varieties with significant differences of genetic background and determined the phenotypic data of stem strength in 2014,2015 and 2016.A total of 369SSR markers were used to genotype the panel and perform association analysis by GLM and MLM.Then,the Annong 0711/Henong 825 RILs population（F₆,362 lines）was used to validate the effects of the two major loci for lodging resistance on chromosomes 5A and 3B.Furthermore,the two parents（Annong 0711 and Henong 825）and two bulks from Annong0711/Henong 825 RILs population were genotyped using the 660K SNP array.According to SNP markers within the major QTL region,the two CAPS markers were developed to confirm the stability and phenotypic effects of the major locus on chromosome 5A.The results can lay the foundation for breeding wheat varieties with lodging resistance and also provide useful information for understanding the genetic mechanism of lodging resistance in wheat.The main results are as follows:（1）Stem strength phenotypes were determined in the natural population consisted of 105 wheat varieties in three environments.The correlation analysis showed that there were significantly positive correlations（P<0.01）among stem strengths,indicating stability of the stem strength trait across environments.（2）SSR genotypes and stem strength phenotypic data of the natural population were used to perform association analysis by GLM and MLM.A total of 53 markers were significantly associated with stem strength,mainly distributing on chromosomes 1D、3A、3B、4B、5A and6D.Thirteen markers significantly associated with stem strength were detected in more than two environments,and located on chromosomes 4BL（barc1096,barc199,and gwm495）,7BL（barc176）,3BS（barc268）,and 3AL.（barc314）,4AL（barc343）,3DS（cfd152）,6DL（cfd37）,6AS（gwm459）,2BS（wmc154）,1D/2A（wmc179）,and 4BS（wmc413）;Particularly,three markers significantly associated with stem strength were detected in all three environments,and distributed on chromosomes 4BL（barc1096）,3AL（barc314）,and 3BS（barc268）.（3）Using the Annong 0711×Henong 825 RILs（F₆）population containing 362 lines,39polymorphic SSR markers were screened on chromosomes 5A and 3B.The two loci Qssahau-5A and Qssahau-3B on chromosomes 5A and 3B were mapped the interval of gwm443-gwm156 and barc358-wmc615,explaining 3.02%-3.20%and 2.42%-3.38%of phenotypic variations,respectively.（4）Two CAPS markers AX-109445097（28.28 Mb）and AX-95200348（445.27 Mb）on chromosome 5A were developed based on the two SNP markers from the Wheat 660K Chip through scanning the two parents and two bulks of Annong 0711/Henong 825 population.The results showed that the CAPS marker AX-109445097 is closely linked to the Qssahau-5A locus.更多还原