猪基因组信息资源的整合与利用

猪基因组图谱已得到极大发展,猪基因组计划已启动并在实施之中。利用QTL扫描,候选基因分析、基因阵列分析、生物信息学、比较基因组学等工具,已经发现了很多影响猪主要经济性状的基因或基因标记。利用标记辅助选择,结合基因标记和常规生产性能信息,可以极大地改进养猪业重要的经济性状。本文对猪的基因组学、生长速度、瘦肉率。饲料吸收,肌肉品质、窝产仔数及疾病抗性等主要经济性状的研究进展及标记辅助选择在猪生产中的应用进行综述。     

Evaluation of the effects of five QTL regions on Fusarium head blight resistance and agronomic traits in spring wheat (Triticum aestivum L.)

Fusarium head blight (FHB) is an important disease of wheat (Triticum aestivum L.). The aim of this study was to determine the effects of quantitative trait locus (QTL) regions for resistance to FHB and estimate their effects on reducing FHB damage to wheat in Hokkaido, northern Japan. We examined 233 F₁-derived doubled-haploid (DH) lines from a cross between ‘Kukeiharu 14’ and ‘Sumai 3’ to determine their reaction to FHB during two seasons under field conditions. The DH lines were genotyped at five known FHB-resistance QTL regions (on chromosomes 3BS, 5AS, 6BS, 2DL and 4BS) by using SSR markers. ‘Sumai 3’ alleles at the QTLs at 3BS and 5AS effectively reduced FHB damage in the environment of Hokkaido, indicating that these QTLs will be useful for breeding spring wheat cultivars suitable for Hokkaido. Some of the QTL regions influenced agronomic traits: ‘Sumai 3’ alleles at the 4BS and 5AS QTLs significantly increased stem length and spike length, that at the 2DL QTL significantly decreased grain weight, and that at the 6BS QTL significantly delayed heading, indicating pleiotropic or linkage effects between these agronomic traits and FHB resistance.     

Progress of genome wide association study in domestic animals

ABSTRACT: Domestic animals are invaluable resources for study of the molecular architecture of complex traits. Although the mapping of quantitative trait loci (QTL) responsible for economically important traits in domestic animals has achieved remarkable results in recent decades, not all of the genetic variation in the complex traits has been captured because of the low density of markers used in QTL mapping studies. The genome wide association study (GWAS), which utilizes high-density single-nucleotide polymorphism (SNP), provides a new way to tackle this issue. Encouraging achievements in dissection of the genetic mechanisms of complex diseases in humans have resulted from the use of GWAS. At present, GWAS has been applied to the field of domestic animal breeding and genetics, and some advances have been made. Many genes or markers that affect economic traits of interest in domestic animals have been identified. In this review, advances in the use of GWAS in domestic animals are described.     

利用棉花纤维品质相关QTL评价海陆渐渗品种品质初探

 选用第7、13、25号染色体上纤维品质相关QTL(Quantitative trait locus)密集分布区间的48对SSR（Simple sequence repeat）引物,对48份棉花种质进行多态性检测,研究结果显示在实验材料中3对SSR引物具有陆海差异多态性,相关分析表明3个优质基因SSR位点与纤维长度和纤维强度达到极显著相关。通过与海岛棉带型比对、追踪,从分子水平上明确了这些品种中来源于海岛棉渐渗于陆地棉的优异基因区段,为下一步分子标记辅助聚合育种提供了理论参考。     

结球甘蓝抽薹开花时间性状的 QTL 定位及分析

在已构建的结球甘蓝AFLP、SSR和SRAP标记高密度遗传图谱的基础上,运用MapQTL 4．0软件对结球甘蓝F2群体抽薹、开花时间两性状分别进行QTL定位和分析。最终检测到2个控制甘蓝抽薹时间性状的QTL（ qbt-3-2、qbt-9-1）,以及一个同开花时间性状相关的QTL（qft-9-1）,分别位于连锁群LG3与LG9上,这3个QTL均为增效位点,共解释甘蓝抽薹、开花时间性状变异的17．5％,22．7％;同时得到与QTLs共分离的2个分子标记E46 M52-5、me26-em13-1,均可作为辅助选育甘蓝耐抽薹品种的标记使用,这将为结球甘蓝耐抽薹品种的选育提供理论依据。     

QTL analysis for early-maturing traits in cotton using two upland cotton (Gossypium hirsutum L.) crosses

Making use of the markers linked closely to QTL for early-maturing traits for MAS (Marker-assisted selection) is an effective method for the simultaneous improvement of early maturity and other properties in cotton. In this study, two F₂ populations and their F_2:3 families were generated from the two upland cotton (Gossypium hirsutum L.) crosses, Baimian2 × TM-1 and Baimian2 × CIR12. QTL for early-maturing traits were analyzed using F_2:3 families. A total of 54 QTL (31 suggestive and 23 significant) were detected. Fourteen significant QTL had the LOD scores not only > 3 but also exceeding permutation threshold. At least four common QTL, qBP-17 for bud period (BP), qGP-17a/qGP-17b (qGP-17) for growth period (GP), qYPBF-17a/qYPBF-17b (qYPBF-17) for yield percentage before frost (YPBF) and qHFFBN-17 for height of first fruiting branch node (HFFBN), were found in both populations. These common QTL should be reliable and could be used for MAS to facilitate early maturity. The common QTL, qBP-17, had a LOD score not only > 3 but also exceeding permutation threshold, explaining 12.6% of the phenotypic variation. This QTL should be considered preferentially in MAS. Early-maturing traits of cotton are primarily controlled by dominant and over-dominant effects.     

Detection and verification of QTLs associated with heat-induced quality decline of rice (Oryza sativa L.) using recombinant inbred lines and near-isogenic lines

Decline in the apparent quality of rice (Oryza sativa L.) grain due to high temperatures during ripening recently became a major concern in many areas in Japan. The occurrence of white-back kernels (WBK) is one of the main problems of heat-induced quality decline. We identified QTLs associated with the occurrence of WBK using recombinant inbred lines (RILs) and verified their effects using near-isogenic lines (NILs). The QTL analysis used F₇ and F₈ RILs derived from ‘Hana-echizen’ (HE), which is tolerant to high temperature, × ‘Niigata-wase’ (NW), which is sensitive to high temperature. Four QTLs were identified on chromosomes 3, 4, 6, and 9 (qWB3, qWB4, qWB6 and qWB9). To verify the effects of qWB6 and qWB9, we developed two NILs in which qWB6 or both were introduced from HE into the NW background. The HE allele at qWB6 significantly decreased WBK under multiple environments. The combination of qWB6 and qWB9 in an F₂ population derived from a cross between a NIL and NW showed that the NW allele at qWB9 significantly decreased WBK if the qWB6 allele was HE. These results will be of value in marker-assisted selection for the breeding of rice with tolerance to heat-induced quality decline.     

甘蓝型油菜主花序有效角果数QTL定位

为分析甘蓝型油菜主花序有效角果数的遗传标记,以ZY036×51070杂交构建的双单倍体(DH)为材料,采用2010-2012年在武汉、阳逻、青海和襄阳三年四点五个试验的检测数据,运用WinQTL Cartographer 2.5软件进行主花序有效角果数QTL定位分析。研究共检测到10个与主花序有效角果数相关的QTL,表型变异是9.33%～31.60%,LOD(极大似然函数比的常用对数)值是2.51～5.37,加性效应是2.71～8.09。而且在染色体A1、A5、C1和C9上的4个QTL都可以在2个不同的试验中重复检测到。试验还得到QTL区间的16个连锁标记,其中有8个距离QTL的最大峰值不足1cM。