动物生长发育中主基因的QTL定位法

将系统学研究动物生长发育的方法和控制数量性状主基因在遗传标记图谱上的定位相结合,提出了动物生长发育过程中任一时刻的数量性状基因座位的定位方法（ＱＴＬ）。并对控制数量性状的主基因表达的时序,传统的基因遗传参数的估计,以及系统分析在分子遗传中的应用前景进行了讨论。     

小麦粒长和粒宽的QTL定位分析

【目的】粒长、粒宽是小麦种子重要的形态性状,该性状对籽粒的外观商品品质、产量及磨粉品质均至关重要,研究不同环境条件下小麦粒长、粒宽的单个标记和复合区间作图的QTL定位,对小麦粒长、粒宽的分子标记辅助选择具有重要参考作用。【方法】应用一个由115个系组成的W7984/Opata 85重组自交系(RIL)群体,建立了由394个DNA分子标记组成的遗传连锁图,在2种不同环境条件下对小麦粒长、粒宽进行了单个标记的回归分析和复合区间作图的QTL定位。【结果】在单个标记的回归分析中检测到5个粒长的QTLs、3个粒宽的QTLs;复合区间作图分析结果表明,控制粒长的QTLs分别位于5BL和7DS上,在5BL上的贡献率为20.20%~20.81%,LOD值为4.50~4.55;在7DS上的贡献率为13.54%~13.91%,LOD值为2.94~3.20。控制粒宽的QTL位于2B上,贡献率为13.71%~19.30%,LOD值为2.98~4.18。【结论】位于5B和7D上的控制粒长的QTL和位于2B上的控制粒宽的QTL在2种条件下均能检测到。     

陆地棉重组近交系产量及其构成因素的QTL分析

利用爱字棉1517×德州047重组近交系(recombinant inbred lines, RIL)中G6群体构建的SSR遗传连锁图谱及基于混合线性模型的复合区间作图法对QTL进行定位,并对主效QTL,加性×加性上位性QTL及与环境互作效应进行分析,为利用分子聚合方法提高产量提供理论依据。对2006年、2008年以及2009年的产量性状进行分离分析,检测到24个不同年份的主效QTL,其中相关于单株籽棉、单株皮棉、衣分、子指以及单株铃数的分别检测到1个不同年份稳定存在的主效QTL;对3年的产量性状作环境因子联合分析,检测到14个主效QTL,其中6个与环境互作,检测到20对加加上位性QTL,其中7对与环境互作。不同年份检测的稳定且受环境影响小或不受环境影响的与近处标记紧密连锁的主效QTL可用于分子标记辅助选择,以提高育种的效率。     

Fine mapping of quantitative trait loci affecting organ weights by mouse intersubspecific subcongenic strain analysis

The genetic architecture of organ weights is not well understood. In this study, we fine‐mapped quantitative trait loci (QTLs) affecting organ weights by characterizing six intersubspecific subcongenic mouse strains with overlapping and non‐overlapping genomic regions on chromosome 2 derived from wild Mus musculus castaneus. QTLs for heart, lung, spleen and kidney weights were revealed on a 6.38‐Mb genomic region between two microsatellite markers, D2Mit323 and D2Mit472. Effects of the castaneus alleles at the organ weight QTLs were all opposite in direction to a body weight QTL previously mapped to the same genomic region. In addition, new QTLs for lung and kidney weights were revealed on a different 3.57‐Mb region between D2Mit205 and D2Mit182. Their effects were dependent on that of another body weight QTL previously mapped to that genomic region. The organ weight QTLs revealed were all duplicated in independent analyses with F₂ intercross populations between subcongenic strains carrying these QTLs and their background strain. The findings suggested that organ weights are not exclusively regulated by genetic loci that commonly influence overall body weight and rather that there are loci contributing to the growth of specific organs only.     

大豆生育期性状的遗传及QTL定位研究

综述大豆生育期性状遗传及基因定位研究进展,讨论当前的研究重点和今后可能的研究方向,以期为相关研究提供参考。     

与大白菜干烧边性状相关的SSR和SRAP标记分析

以大白菜感干烧边品种A67和抗干烧边品种A53配制的141个F2代单株组成的群体为材料,双亲DNA构建大白菜感病池和抗病池,对104对SSR引物和320对SRAP引物进行筛选,并对与干烧边性状相关的QTL和对应的连锁关系进行了初步分析,获得2个与大白菜干烧边性状相关的QTL,同时获得3个与这2个QTL连锁的标记,其中A29-890和E6-400标记与其最近QTL位点的连锁距离分别为1.5cM和7.1cM。为大白菜抗干烧边性状的分子辅助育种奠定了基础。     

控制大白菜和白菜型油菜叶缘裂刻的QTL 定位及分析

 利用叶缘光滑无裂刻的大白菜[Brassica campestris L. ssp. pekinensis（Lour）Olsson]材料‘Z16’和叶缘深裂的白菜型油菜（Brassica campestris L. var. yellow sarson Prain）‘Yellow Sarson 143’构建的120 个株系的BC₂DH 群体及已构建的包含10 个连锁群的遗传图谱,利用JoinMap4 软件及MQM 作图法,对叶缘裂刻性状进行QTL 定位分析。3 次重复试验中,分别在第3、10 号染色体上的相同位置各检测到1 个控制叶缘裂刻性状的QTL,具有重复性。各QTL的LOD值在7.66 ~ 18.99 间,可解释26.4% ~ 44.7%的表型变异。通过大白菜与拟南芥注释基因比对,生物活性赤霉素（GA₁、GA₄）合成的关键基因BrGA20ox3位于第10 染色体的QTL 区域,对143 施加外源赤霉素GA₃ 能明显抑制叶缘裂刻表型,因此BrGA20ox3为控制叶片裂刻的可能候选基因。对BrGA20ox3 克隆测序获得与该基因共分离的特异标记（BrIDlobe-2）,对进一步研究叶缘裂刻性状及分子标记辅助育种具有重要的意义。     

Quantitative trait loci for resistance to Fusarium head blight in recombinant inbred wheat lines from the cross Huapei 57-2 / Patterson

Fusarium head blight (FHB), primarily caused by Fusarium graminearum in North America, often results in significant losses in yield and grain quality of wheat (Triticum aestivum L.). Evaluation of FHB resistance is laborious and can be affected by environmental conditions. The development of DNA markers associated with FHB quantitative trait loci (QTL) and their use in breeding programs could greatly enhance selection. The objective of this study was to identify the location and effect of QTLs for FHB resistance using simple sequence repeat (SSR) markers. A population of wheat recombinant inbred lines derived from the cross ‘Huapei57-2’/‘Patterson’ was characterized for type II resistance in one field experiment and two tests under controlled conditions in the greenhouse. Bulked segregant analysis followed by QTL mapping was used to identify the major segregating QTLs. Results indicate that ‘Huapei 57-2’ may have the same resistance allele as ‘Sumai3’ at a QTL located on the short arm of chromosome 3B. Other QTLs of lower effect size were identified on the long arm of 3Band on chromosomes 3A and 5B. Our findings along with results from other studies demonstrate that the effect of the QTL on3BS is large and consistent across a wide range of genetic backgrounds and environments. Pyramiding this QTL with other FHB QTLs using marker-assisted selection should be effective in improving FHB resistance in a wheat breeding program. This revised version was published online in August 2006 with corrections to the Cover Date.     

棉花抗黄萎病基因的QTL定位

以高感黄萎病的陆地棉品种"邯郸208"与高抗黄萎病海岛棉品种"Pima90"的136个F2单株为作图群体,构建了一个包括17个连锁群、标记间平均间距18.61cM、全长1842.8cM的陆海种间分子标记遗传连锁图,该图约覆盖棉花基因组的36.8%。单因子方差分析和复合区间作图检测到与黄萎病抗性相关的3个QTL,分别位于第四连锁群和第七连锁群上,分别解释表型变异方差的15.39%、54.11%和57.18%。初步认为海岛棉"Pima90"对陆地棉"邯郸208"的黄萎病抗性由两个主效QTL和一个微效QTL共同控制。     

Quantitative trait loci (QTL) affecting sugars, organic acids and other biochemical properties possibly contributing to flavor, identified in four advanced backcross populations of tomato

Although the Advanced Backcross strategy has proven very useful for QTL detection in tomato, it has been used mainly in identifying QTL for agronomic traits such as yield, color, etc. Tomato flavor is an important quality characteristic, yet it has been difficult to assess flavor or traits that affect it. In this study the AB-QTL strategy was applied to four advanced backcross populations to identify QTL for biochemical properties that may contribute to the flavor of processed tomatoes, such as sugars and organic acids. A total of 222 QTL were identified for 15 traits, including flavor as assessed by a taste panel. Correlations of certain biochemicals with flavor and possible methods of assessing and improving flavor are discussed. In particular, QTL with very significant effects associated with the ratio of sugars/glutamic acid, a trait highly correlated with improved flavor, have been identified as good targets for future work in improving the flavor of tomatoes. This revised version was published online in August 2006 with corrections to the Cover Date.