【作者】 吴建忠；

【导师】 周永明；

【作者基本信息】 华中农业大学 ， 作物遗传育种， 2010， 硕士

【摘要】 油菜是我国主要的油料作物,提高油菜籽产量和含油量以增加单位面积产油量是当前油菜育种的首要目标。本研究重点分析了甘蓝型油菜主花序不同部位种子数目和重量的差别。为度量这种差别,我们分上部和下部两个区段,重点对角果粒重和角果粒数进行分析,以此衡量基因型之间花序不同部位种子粒数和粒重形成可能的差异。利用加倍单倍体(DH)群体构建的图谱,对上述结实相关性状以及单株产量等13个性状进行了QTL定位分析,同时对蛋白质含量、含油量、总硫甙含量等3个品质相关性状也分上下段进行了QTL定位和分析,主要结果如下：1.以SSR标记为主,构建了一张甘蓝型油菜遗传连锁图谱。该图谱共有488个标记,包含19个连锁群,全长为2956.3cM,标记间平均图距为6.06cM,与已发表的图谱有较好的一致性。2.所考察的株高、一次有效分枝数、分枝高度、主花序长度、角果长度(分为主花序上部和下部,以下略记为上、下)、角果粒数(上、下)、角果粒重(上、下)、主花序角果数、单株产量、千粒重等性状均表现为正态分布。性状在家系间的表型差异达到极显著水平,遗传力的变异范围为42.34%～81.64%。不同地点相同性状之间(除单株角果总数外)均存在极显著正相关；同一地点不同性状之间的相关性也很明显。角果长度上部遗传力高于下部,而粒数和粒重则为下部遗传力高于上部。单株产量与株高、一次有效分枝数、粒数(上、下)、粒重(上、下)、主花序长度、主花序角果数呈极显著正相关,而与一次分枝高度和角果长度(上、下)相关不显著；3.蛋白质含量、含油量和总硫甙含量上下部位分析结果表明,各性状上下部位含量在两年间均表现出极显著差异。同一性状不同年份间亲本表现差异较大,而F1表现差异不明显,含油量受环境的影响较蛋白质含量和总硫甙含量要更大些；4.采用复合区间作图法对2008年和2009年所考察性状分上下部位进行QTL定位,取LOD临界值为2.5。结实相关性状共检测到QTL92个,单位点贡献率在3.66%～25.49%范围,LOD值范围为：2.51～15.61,品质相关性状共检测到QTL30个,单位点贡献率在3.93%～25.09%范围,LOD值范围为：2.54～14.44,生育期相关性状共检测到QTL26个,单位点贡献率在3.54%～17.77%范围,LOD值范围为：2.59～10.75,共计148个QTLs,分别位于不同的连锁群上,部分QTLs在2年间可以重复检测到。更多还原

【Abstract】 Rapeseed is one of the major oil crops in China. It is the primary objective to increase oil production per unit through the improvement of yield and oil content of rapeseed in the current rapeseed breeding. This study was focused on analysis of seed numbers and weight in the lower and upper parts of the main inflorescence of Brassica napus. A genetic map was constructed with a doubled haploid (DH) population to map seed yield per plant and other related traits as well as three quality traits including protein content, oil content, and the total glucosinolate content. The main results are as follows:1. A genetic linkage map of Brassica napus with SSR markers mainly was constructed. The map includes 488 markers, and contains 19 linkage groups with the total length of 2956.3cM, average marker distance of 6.06cM. The constructed map is in good agreement with published maps.2. The following traits were examined: plant height, first branch number, branch height, length of main raceme, pod length (upper and lower section on main raceme, expressed as Upper and Lower thereafter), grain number per pod (Upper and Lower), seed weight on the main raceme (Upper and Lower), grain yield per plant, grain weight. All the traits showed a normal distribution and the phenotypic differences among genotypes reached a significant level. The heretabjilities of the traits vary in a range of 42.34%-81.64%. Except the total number of pods per plant, the correlations of the same trait at different locations as well as the correlations between different traits in the same location are significant. The heritability of upper pod length is higher than lower pod length while the lower grain number and grain weight have higher heretabilities than the upper parts. Yield per plant and plant height, first branch number, grain number (upper and lower), weight (upper and lower), the main inflorescence length of main raceme was significantly correlated with a high degree of branching and pod length (the upper and lower) were not significantly correlated;3. Analysis between the upper and lower parts of protein content, oil content and total glucosinolate content showed that upper and lower parts of the characters were significantly different in two years. For a same trait, two parents showed large difference in different years, but no significant difference between F1 performances. Oil content was more affected by the environment than the protein content and total glucosinolate content;4. Using composite interval mapping and LOD=2.5 as the critical value QTL for the upper and lower parts of pod length, seed numbers and seed weight and other related trais were investigated positioning 2008 and 2009. In total,92 QTLs were detected for above studied traits. The mapped QTL contributed to trait variation ranging 3.93%-25.09% with the LOD value range of 2.51-15.61. Total 30 QTLs were detected for quality traits, contributing to the variation of 3.93%-25.09% range with LOD values range of 2.54-14.44. Total 26 QTLs were detected for flowering date and related traits, contributing to the variation of 3.54%-17.77% with the LOD value range of 2.59-10.75. Over all 148 QTLs are located in different linkage groups and some of the QTLs can be repeatedly detected in two years.更多还原