【作者】 黄碧光；

【导师】 吴为人；

【作者基本信息】 福建农林大学 ， 作物遗传育种， 2005， 博士

【摘要】 大麦是一种重要的农作物。大麦突变体的获得和深入研究是开展大麦基因克隆和功能研究的关键,是利用生物技术手段改良大麦农艺性状的基础。大麦多棱分枝穗突变体（prbs）,是本课题组从玉米总DNA浸泡莆大麦2号花序的处理二代中发现的,表现为多小穗数目不规则,并且有产生穗分枝的倾向,从而呈现不规则多棱。初步遗传分析表明,该突变性状相对于受体亲本莆大麦2号的二棱为隐性,是穗棱型变异的一种,受一隐性基因prb控制。已发现的大麦穗棱型基因分别位于5条染色体上,即vrs1（2H）、vrs2（5H）、vrs3（1H）、vrs4（3H）和int-c（4H）,这些基因等位基因内互作和等位基因间的互作,产生各种穗棱型。大麦穗棱型除二棱外,六棱是最常见的。本项目进一步研究了prb与六棱基因（记为n）之间的遗传关系,并利用SSR标记对prb和n进行了定位。另外,还对互作基因定位的策略进行了研究。主要结果如下: 1、对prbs的遗传分析:建立四个大麦杂交组合（六棱×二棱、多棱分枝×二棱、多棱分枝×六棱和六棱×多棱分枝）,对其F₁、F₂和F₃的穗棱型进行了调查分析。结果显示:在六棱×二棱组合中,六棱相对于二棱受一对隐性基因（n）控制;在多棱分枝×二棱组合中,多棱分枝相对于二棱也受一对隐性基因（prb）控制;在多棱分枝×六棱和六棱×多棱分枝组合F₂代中,二棱∶六棱∶多棱分枝=9∶3∶4,穗棱型表现为受两对基因互作控制,其中一对基因控制二棱和六棱的表现,六棱为隐性,另一对基因控制多棱分枝与否的表现,多棱分枝为隐性,并且prb/prb对二棱/六棱基因具有隐性上位作用。 2、互作基因定位的策略:基因互作是常见的遗传现象,但目前还没有提出互作基因定位的专门方法。考虑到Bulked Segregant Analysis（BSA）结合Mapmaker/Exp软件是目前许多学者所熟悉的定位单个主基因的常用更多还原

【Abstract】 Barley was an important crop. Acquiring barley mutants and research on them was key for gene clone and function analysis, and was the base of improvement for agricultural character using biotechnology. Poly-row-and-branched spike （prbs） in barley was a mutant from D₂ of Pudamai 2 whose inflorescence was treated with maize nuclear DNA. prbs had multi-spikelet and the number of spikelet on every spike axis’s node was not definite, and its spike had the tendency to branch, so its spike behaved non-regular poly-rowed. Preliminary genetic analysis demonstrated that the mutant character was recessive contrast to two-row of Pudamai 2, controlled by one pair of recessive genes （prb）, and was one variant of row- types. Genes controlling row-types detected distributed on 5 chromosomes, respectively were vrs1 （2H） vrs2 （5H）, vrs3 （1H）, vrs4 （3H） and int-4 （4H）, and interaction in the alleles and between the alleles generated various row-types. Six-row was the most common row-type besides two-row. We further studied the genetic relationship between prb and genes controlling six-row（recorded as n）, and determined the location on chromosome for prb and n using SSR, and studied the strategies for mapping interactive genes. Main results were summarized as follows:1. Genetic analysis for prbs: Four barley crosses （six-row x two-row, prbs x two-row, prbs x six-row and six-row x prbs） were built, and the row types of F₁, F₂ and F₃ of the four crosses were investigated and analyzed. For the cross six-row × two-row, six-row in contrast to two-row is controlled by one pair of recessive genes （recorded as n）; and for the cross prbs x two-row, prbs mutant traits in contrast to two-row is also controlled by one pair ofrecessive genes （recorded as prb）; for the crosses prbs x six-row and six-row x prbs, two-row:six-row:prbs=9:3:4 in F2, so row types are controlled by two pairs of genes, one pair controls two-row vs. six-row, the other controls prbs mutant traits vs. not, prbs mutant traits is controlled by recessive genes （prb）, and prblprb has recessive epistasis on the pair of genes controlling two-row vs. six-row.2. Strategies for mapping interactive genes: Gene interaction was a common genetic phenomenon. But special ways for locating intertactive genes hadn’t been reported so far. Common for single gene location, Bulked Segregant Analysis （BSA） combining Mapmaker/Exp was familiarized by many researchers. Considering this, we developed this technique for interactive genes location. The basic strategy for locating interactive genes put forward in this study was generally fit for interactions controlled by two pairs of independent genes. Usually, only F2 group was needed for mapping interactive genes by "BSA+ Mapmaker/Exp", F3 were needed for BSA for one pair of genes in inhibition effect and two pairs of genes in complementary effect. Two were key in the basic strategy: 1) found two phenotypes between which alleles on the target locus differed, and formed two responding DNA pools for BSA; 2) among the segregating group, found individuals having definite genotype to form the mapmaking sub-group. Usually, only one pair of DNA pools for BSA was needed for two pairs of interactive genes, but DNA pools for BSA were needed respectively for every pair of genes in inhibition effect. Sub-groups for mapmaking could be found simultaneously suitable for two pairs of interactive genes in all types of interaction. Thus heighten the efficiency of BSA and Mapmaker/Exp for interactive genes. So this strategy for mapping interactive genes was practicable. The mapping groups for更多还原