【作者】 马靖；

【导师】 张正圣；

【作者基本信息】 西南大学 ， 遗传学， 2010， 硕士

【摘要】 棉花是世界上重要的纤维作物。棉属约50种,包括四个栽培种：亚洲棉、非洲棉、陆地棉、海岛棉,其中陆地棉占世界原棉产量的95%以上。我国是世界上最大的棉花生产国和消费国,也是最大的纺织品生产国和出口国,但目前国产棉花的质量却难以满足纺织工业的多种需求。提高我国棉花的质量既可满足国内纺织工业多元化用棉的需要,稳定和发展棉花生产,又可以提高我国原棉在国际市场上的竞争力。因此很有必要进一步了解我国棉花纤维品质的现状。棉花产量和品质表现型是基因型与环境共同作用的结果,致使常规育种依据表型选择的效率受到限制。通过分子标记辅助选择可显著提高育种效率,分子标记辅助选择需要构建遗传连锁图谱,并定位数量性状基因座(quantitative trait locus,QTL).本研究采用三个遗传基础差异较大且生产上广泛应用的陆地棉构建群体,利用分子标记技术构建棉花的遗传连锁图谱,结合纤维品质性状的分析,定位控制棉花纤维品质的QTL。研究结果如下所示：1.亲本及三亲杂交群体的品质性状的表现纤维品质性状马克隆值、纤维比强度、纤维长度性状在三个亲本中有较大的差异。7235的纤维长度显著高于中棉所35和渝棉1号。渝棉1号和中棉所35的马克隆值显著高于7235。渝棉1号和7235的纤维比强度显著比中棉所35高。整齐度和伸长率差异不显著。三亲杂交群体的纤维长度范围为28.40-34.83mm,平均为32.20mm:整齐度范围为81.60-87.50%,平均85.35%；马克隆值范围为3.20-5.20之间,平均4.11;伸长率6.30％-6.80％,平均值6.57%;比强度范围为28.9-39.3cN/tex之间,平均34.02 cN/tex.群体的纤维品质性状连续分布,表现超亲优势。2.引物多态性分析在4612对SSR引物中,238对在三个亲本间(渝棉1号、中棉所35、7235)表现有效多态性,多态比例为5.2%,其中BNL为11.1％.NAU9.0％、JESPR为6.1％.CIR为4.1％.MUCS为4.0％.MUSS为3.2％.MGHES为2.3％.MUSB为1.7％。3.三亲杂交群体标记基因型检测利用238对多态性引物检测三亲杂交群体172个单株,共获得244个多态性位点,6对引物产生两个位点。244个位点中有1m类型位点68个,占27.87%; np类型位点98个,占40.16％; hk类型位点65个,占26.63％；ef-eg类型位点13个,占5.33%。4.遗传连锁图谱构建对244个标记位点利用遗传图谱进行遗传连锁分析,所构建的遗传连锁图谱有171个位点和42个连锁群,84个位点未定位到遗传连锁图谱上。39个连锁群对应22个染色体,3个连锁群未定位染色体。连锁群的长度为2.7-100cM,每个连锁群含2-40个分子标记,标记平均间隔8.45cM,总长1445.5 cM,基因组的覆盖率为32.5%。5.品质性状QTL定位利用复合区间作图法分析该三亲本杂交群体纤维品质性状,共得到10个纤维品质QTLs,其中3个与纤维长度相关,分布在Chr.3.Chr.12、Chr.15可解释表型变异的11.2％-45.3％;2个与整齐度相关,分布在Chr.19.Chr.21上,可解释表型变异的6.5％、34.9％;3个与马克隆值相关,分布在Chr17、Chr23.Chr24上,可解释表型变异的8.8％-29.2％: 2个与比强度相关,分布在Chr15、Chr25上,可解释表型变异的6.9％、6.2％。更多还原

【Abstract】 Cotton is the most important fiber crop in the world. Cotton genus comprises of about 50 species, and cultivated species include Asian cotton, African cotton, upland cotton and Sea Island cotton. Upland cotton accounted for 95% of the total production. China is the world’s largest cotton producer and consumer, and also the largest textile producer and exporter. However, the fiber quality of domestic cotton cannot meet the needs of textile industry. The development of fiber quality can enhance the competitiveness of our raw cotton in the international market.The yield and quality traits result from the interaction between genotype and environment, so limted the efficiency of conventional breeding which based on phenotypic selection. Molecular marker-assisted selection technology can significantly improve the efficiency of breeding constructing. The molecular marker-assisted selection technology need construct linage map and locate quantitative trait locus (QTL). The present study uses three upland cotton cultivars to establish mapping population and construct genetic map with SSR marker. The fiber quality traits of three parent cross population (Yumian 1×Zhong 35)×(Yumian 1×7235) F1 were used to map QTLs affecting fiber quality. The mainly results were as following:1. Fiber quality of mapping parents and composite populationFiber quanlity traits including Micronaire, fiber strength and fiber length traits were quite different in three parents whereas fiber uniformity and elongation are not significantly different. The fiber length of 7235 was better than that of Zhong 35 and Ynmian 1. The mironaire of 7235 was lower than that of Zhong 35 and Ynmian 1. The fiber strength of Ynmian 1 was lower than that of Zhong 35 and 7235.For three parent cross population, fiber length ranges from 28.40 to 34.83 mm, with a mean of 32.20 mm. Length uniformity ranges from 81.60% to 87.50%, with a mean of 85.35%. Mironaire ranges from 3.20 to 5.20, with a mean of 4.11. Fiber elongation ranges from 6.30% to 6.80%, with a mean of 6.57%. Fiber strength ranges from 228.9 to 39.3cN/tex, with a mean of 34.02 cN/tex. Five fiber quality traits show continuous distribution and segregation beyond three parents. 2. Primer pair polymorphism between three parentsOut of 4612 cotton SSR primer pairs, a total of 238 show polymorphism among three mapping parents, Yumian 1, Zhong 35 and 7235, the polymorphic markers acconted for 5.2% of the total primer pairs.3. Genotyping tree parent cross populationThe 238 polymorphic primer pairs were used to genotype the 172 individual plants from (Yumian 1×Zhong 35)×(Yumian 1×7235) F1 population and 244 loci were obtained.4. Construction of upland cotton genetic linkage mapA total of 244 loci were comducted linkage analysis, and a map including 175 markers and 42 linkage groups was constructed whereas 84 markers were not located on any linakeage group. Thirty-nine linkage groups were located on 22 chromosomes. The map covered 1445.5cM. accounting for 32.5% of the cotton genome, with an average distance of 8.45 cM between two markers. The length of linkage groups ranged from 2.7 to 100 cM and the markers on the groups ranged from 2 to 40.5. QTL mapping of fiber qualityBased on composite interval mapping, ten QTLs for fiber quality was located on nine chromosomes. Three QTLs identified for fiber length distributed on Chr3. Chrl2, Chr15,and explained the fiber length variance from 10.2 to 35.8%. Two QTLs identified for length uniformity distributed on Chrl9 and Chr21, and explained the fiber length uniformity from 6.5% to 34.9%. Three QTLs for Micro were located on chrl 7, chr 23 and chr 24, and explained phenotypic variance from 8.8% to 29.2%. Two QTL for fiber strength were located on chr 15 and chr25, and explained 6.9% and 6.2% of phenotypic variance.更多还原