【作者】 沈熙；

【导师】 吴江生； 刘克德；

【作者基本信息】 华中农业大学 ， 作物遗传育种， 2008， 硕士

【摘要】 油菜是我国最重要的油料作物,是食用植物油和优质蛋白的重要来源。据统计,我国菜籽油消费量约占食用植物油消费量的35%,菜籽饼粕消费量约占植物饼粕消费量的25%。油菜角果既是重要的储存器官,又是重要的光合器官,它具有“库”和“源”的双重作用。一些研究表明,通过培育长角果品种可以提高油菜产量潜力。由于油菜的角果长度性状是由多基因控制的数量性状,表现为连续变异,受环境的影响较大,不能依照质量性状的处理方法将单个基因的效应区分开。近年来,数量遗传学和现代生物技术的发展为作物遗产育种赋予了新的活力,借助DNA分子标记和QTL定位,能够将复杂的数量性状剖分为若干离散的孟德尔因子所决定的组分,进而确定其在染色体上的位置及其与其它基因的关系。本研究以甘蓝型油菜长角果材料229836和短角果材料23P146-3为试验材料,杂交得到F₁,F₂世代,对角果长度性状进行了遗传研究;应用微卫星（SSR）分子标记构建遗传连锁图,以F₂为分析群体,对角果长、果身长、果喙长等性状进行了初步的QTL定位。其主要结果如下:1、方差分析表明,长角果亲本229836和短角果亲本23P146-3在角果长、果身长、果喙长性状上均存在极显著差异。2、正反交F₁在角果长、果身长、果喙长三个性状上表现均十分接近,在统计上没有显著差异,表明在本组合中,角果长、果身长、果喙长3个性状受核基因控制,不存在母性遗传。3、估算角果长、果身长、果喙长性状的广义遗传力,分别为84.07%,81.67%和85.46%。4、在F₂群体中,角果长、果身长、果喙长这三个性状,均呈连续正态分布,显示均为多基因控制的数量性状。5、采用SSR标记分析F₂群体186个单株的基因型,利用JionMap 3.0软件,得到一张包含19个连锁群,233个标记位点的甘蓝型油菜遗传图谱。图谱总长度为1440.4cM,平均间距为6.2cM。不同连锁群上标记数介于2-38之间,连锁群长度变动在12.3 cM-181.5 cM之间。6、用WinQTLCart2.5复合区间作图法对角果长、果身长、果喙长3个性状进行扫描,共有12个QTL。分别定位在19个连锁群中的4个连锁群上,这些QTL的遗传效应值介于5.51%-19.74%。控制角果长和果身长的均为5个,果喙长的为2个。QTL的总效应分别可解释相应性状变异的16.08%-50.05%。更多还原

【Abstract】 The rapeseed is the most important oil-bearing crop, as well as an important origin of edible vegetable oil and high quality protein. Statistics data showed that the rapeseed oil consumption occupied 35% of edible vegetable oil consumption. The rapeseed cake rice dregs consumption took hold of approximately 25% of the plant cake rice dregs consumption. The rapeseed pod no is not only an important storage organ, also is the important photosynthesis organ, it has the dual function of "the storehouse" and "the source". The cultivation of long-pod variety may enhance the output potential. The pod length is controlled by quantitative trait loci of multi-genes. It is a continuous variation, and influenced larger by the environment, therefore the single gene effect can not be separated by the quality character. Currently, genetic crop breeding has been developed with the development of quantity genetics and modern biological technology. Accompanied by the aid of the DNA markers and the QTL localization, the complex quantity character can be divided into certain separate Mendel factor. Subsequently, the pod length controlled genes are allocated onto specific chromosome region and the distances with other genes are easy to be determined.The hybrid obtains generation F₁ and F₂ were used from a cross between long-pod 229836 and short-pot 23P146-3. A linkage map of the pod length was conducted by micro satellite markers （SSRs）. Taking the F₂ population as analysis content, the full pod length, pod body length and the pot beak length were carried on the preliminary QTL localization. The results were the followings:1. The variance analysis indicated that, the long-pod parent 229836 and the short-pod parent 23P146-3 showed significant differences in the full pod length, the body length and pod beak length;2. The back cross population F₁ didn’t display obvious differences in the full pod length, pod body length and pod beak length, and they showed great similarities instead. This result indicated that these characters were controlled by nuclear genes, and were not affected by maternal DNA;3. The Estimation of heritability of pod length, pod body length and pod beak length were 84.07%, 81.67% and 85.46%;4. The three traits in F₂ population had a continuous normal distribution, indicating the pod length, pod body length and pod beak length were quantitative in nature and controlled by polygenes; 5. SSR markers were used to analyze 186 single plants genotype in F₂ population. A linkage map was produced by JionMap 3.0 software, including 19 linkage groups and a genetic map with 233 loci. The full map length was 1440.4cM, with an average of 6.2cM. The number of locus ranged between 2-38, and the length of linkage groups varied from 12.3 cM to 181.5 cM;6. The three traits were computed by the WinQTLCart2.5, and in total 12 QTLs were detected. These 12 QTLs were allocated in 4 linkage groups among the 19 linkage groups. The genetic effect value of 12 QTLs was situated between 5.51%-19.74%, in which 5 controlled the pod body length and 2 controlled the pod beak length. The QTL total effect separately may explain the corresponding character variation 16.08%-50.05%.更多还原