大豆叶片性状QTL的定位及Meta分析

利用Charleston×东农594重组自交系构建SSR遗传图谱,采用WinQTLCartographer Ver. 2.5软件的CIM和MIM分析方法对2006—2010年(F_2:14~F_2:18)连续5年的大豆叶长、叶宽以及叶柄长数据进行QTL定位,检测到8个与叶长有关的QTL,位于染色体Gm01、02、05、11和18上;9个与叶宽有关的QTL,位于染色体Gm01、03、05、06、11、12和16上;8个与有关叶柄长的QTL,位于染色体Gm01、03、05、06、11、17和18上。2年以上均检测到的叶长QTL为qLL5a、qLL5b、qLL1a和qLL18;叶宽QTL为qLW5a、qLW11a、qLW11b和qLW12;叶柄长QTL为qLSL11b。另外,利用BioMercator2.1的映射功能将国内外常用的大豆图谱上的叶长、叶宽QTL通过公共标记映射整合到大豆公共遗传连锁图谱Soymap2上,将搜集到的35个叶长QTL、37个叶宽QTL和本研究得到的QTL整合分析,最终得到5个大豆叶长的“通用”QTL,位于Gm09、18和19,其置信区间最小可达5.66 cM;4个大豆叶宽的“通用”QTL,位于Gm07、Gm18和Gm19,其置信区间最小可达5.67 cM,为今后对大豆叶片性状QTL精细定位, 提供了有利科学信息。     

水稻卷叶基因RL13的遗传分析和分子定位

叶片形态是理想株型的重要指标之一,叶片适度卷曲有利于理想株型的建成,是水稻超高产育种的重要材料。在EMS诱变籼稻缙恢10号群体中发现一个卷叶突变体,表现叶片筒状卷曲,经过多代连续自交,性状稳定,命名为rl₁₃ (rolled leaf 13)。rl₁₃的叶绿素a、叶绿素b和总叶绿素含量均显著高于野生型对照缙恢10号,类胡萝卜素含量在苗期、孕穗期与野生型相比有显著提高,而抽穗期和成熟期则差异不显著。rl₁₃的三片功能叶的卷曲度与野生型相比均达到极显著差异,但rl₁₃的三片功能叶之间差异不显著。通过石蜡切片分析,突变体叶肉细胞层数变薄,野生型含有的一个较大泡状细胞转变为卷叶突变体的两个大小相近的泡状细胞,导致了叶片弯曲。以该突变体为父本,西农1A为母本配制杂交组合构建F₂遗传群体,结果表明,该卷叶性状由一对隐性核基因控制。选用F₂代分离群体中的1 215个隐性单株作为定位群体,将RL₁₃定位在第6染色体短臂上分子标记RM276和SWU6-1之间,遗传距离分别为1.1 cM和0.2 cM。     

普通小麦对仓储害虫玉米象的抗性QTL分析

以普通小麦品种川农16与人工合成小麦衍生品种川麦42为亲本构建了含有127个株系的重组自交系(RIL)群体,将2008和2009年收获的种子用玉米象(Sitophilus zeamais)虫卵进行接种,并于2009年11月开始储藏,次年8月和10月进行虫害调查。利用复合区间作图法(CIM)对RIL群体的抗虫性进行QTL定位分析。利用2008年收获群体检测到位于3B、2D和3D染色体的3个QTL,贡献率依次为10.2%、8.5%和8.3%;利用2009年收获群体检测到位于3D和4B的2个QTL,贡献率分别为8.5%和11.3%。位于3D染色体Xbarc6–Xgwm112标记区间内的QTL在年度间重复检测到,贡献率为8.3%~8.5%,抗性位点来自川农16。     

运用关联分析定位栽培大豆蛋白11S、7S组分的相关基因位点

大豆贮藏蛋白主要成分是7S和11S球蛋白,大豆贮藏蛋白组分及其亚基组成决定了蛋白质的品质和加工特性。本研究选用134对细胞核SSR标记,对166份栽培大豆微核心种质进行基因分型,运用一般线性回归(general linear model, GLM)和复合线性回归(mixed linear model, MLM)方法进行标记与性状的关联分析,定位大豆蛋白亚基的相关基因。结果表明,2年均检测到的且与蛋白亚基相关联的SSR位点有14个,以MLM方法检测到5个SSR位点(Sat_062、Satt583、Satt291、Satt234和Satt595)与蛋白亚基相关联;7S组分各亚基变异程度较大,是引起11S/7S变异的主要原因;表型变异较大的亚基可能因为相关基因进化中发生重组较多,LD衰减距离较小,导致检测到较少的相关位点。本研究结果对蛋白亚基相关性状的标记辅助选择育种有重要的利用价值。     

Screening and genetic analysis of resistance to peanut stunt virus in soybean: identification of the putative Rpsv1 resistance gene

The peanut stunt virus (PSV) causes yield losses in soybean and reduced seed quality due to seed mottling. The objectives of this study were to determine the phenotypic reactions of soybean germplasms to inoculation with two PSV isolates (PSV-K, PSV-T), the inheritance of PSV resistance in soybean cultivars, and the locus of the PSV resistance gene. We investigated the PSV resistance of 132 soybean cultivars to both PSV isolates; of these, 73 cultivars exhibited resistance to both PSV isolates. Three resistant cultivars (Harosoy, Tsurunotamago 1 and Hyuga) were crossed with the susceptible cultivar Enrei. The crosses were evaluated in the F₁, F₂ and F_2:3 generations for their reactions to inoculation with the two PSV isolates. In an allelism test, we crossed Harosoy and Tsurunotamago 1 with the resistant cultivar Hyuga. The results revealed that PSV resistance in these cultivars is controlled by a single dominant gene at the same locus. We have proposed Rpsv1, as the name of the resistance gene in Hyuga. We also constructed a linkage map using recombinant inbred lines between Hyuga × Enrei using 176 SSR markers. We mapped Rpsv1 near the Satt435 locus on soybean chromosome 7.     

Genome-wide genetic dissection of germplasm resources and implications for breeding by design in soybean

“Breeding by Design” as a concept described by Peleman and van der Voort aims to bring together superior alleles for all genes of agronomic importance from potential genetic resources. This might be achievable through high-resolution allele detection based on precise QTL (quantitative trait locus/loci) mapping of potential parental resources. The present paper reviews the works at the Chinese National Center for Soybean Improvement (NCSI) on exploration of QTL and their superior alleles of agronomic traits for genetic dissection of germplasm resources in soybeans towards practicing “Breeding by Design”. Among the major germplasm resources, i.e. released commercial cultivar (RC), farmers’ landrace (LR) and annual wild soybean accession (WS), the RC was recognized as the primary potential adapted parental sources, with a great number of new alleles (45.9%) having emerged and accumulated during the 90 years’ scientific breeding processes. A mapping strategy, i.e. a full model procedure (including additive (A), epistasis (AA), A × environment (E) and AA × E effects), scanning with QTLNetwork2.0 and followed by verification with other procedures, was suggested and used for the experimental data when the underlying genetic model was usually unknown. In total, 110 data sets of 81 agronomically important traits were analyzed for their QTL, with 14.5% of the data sets showing major QTL (contribution rate more than 10.0% for each QTL), 55.5% showing a few major QTL but more small QTL, and 30.0% having only small QTL. In addition to the detected QTL, the collective unmapped minor QTL sometimes accounted for more than 50% of the genetic variation in a number of traits. Integrated with linkage mapping, association mappings were conducted on germplasm populations and validated to be able to provide complete information on multiple QTL and their multiple alleles. Accordingly, the QTL and their alleles of agronomic traits for large samples of RC, LR and WS were identified and then the QTL-allele matrices were established. Based on which the parental materials can be chosen for complementary recombination among loci and alleles to make the crossing plans genetically optimized. This approach has provided a way towards breeding by design, but the accuracy will depend on the precision of the loci and allele matrices.     

Accuracy of pastoralists' memory-based kinship assignment of Ankole cattle: a microsatellite DNA analysis

This study aimed to estimate the level of relatedness within Ankole cattle herds using autosomal microsatellite markers and to assess the accuracy of relationship assignment based on farmers' memory. Eight cattle populations (four from each of two counties in Mbarara district in Uganda) were studied. Cattle in each population shared varying degrees of relatedness (first-, second- and third-degree relatives and unrelated individuals). Only memory-based kinship assignments which farmers knew with some confidence were tested in this experiment. DNA isolated from the blood of a subsample of 304 animals was analysed using 19 microsatellite markers. Average within population relatedness coefficients ranged from 0.010 ± 0.005 (Nshaara) to 0.067 ± 0.004 (Tayebwa). An exclusion probability of 99.9% was observed for both sire-offspring and dam-offspring relationships using the entire panel of 19 markers. Confidence from likelihood tests performed on 292 dyads showed that first-degree relatives were more easily correctly assigned by farmers than second-degree ones (p < 0.01), which were also easier to assign than third-degree relatives (p < 0.01). Accuracy of kinship assignment by the farmers was 91.9% ± 5.0 for dam-offspring dyads, 85.5% ± 3.4 for sire-offspring dyads, 75.6% ± 12.3 for half-sib and 60.0% ± 5.0 for grand dam-grand offspring dyads. Herd size, number of dyads assigned and length of time spent by the herder with their cattle population did not correlate with error in memorizing relationships. However, herd size strongly correlated with number of dyads assigned by the herder (r = 0.967, p < 0.001). Overall, we conclude that memorized records of pastoralists can be used to trace relationships and for pedigree reconstruction within Ankole cattle populations, but with the awareness that herd size constrains the number of kinship assignments remembered by the farmer.     

浅谈ArcGIS在林业规划设计制图中的应用

结合森林资源规划设计调查内业处理,介绍ArcGIS地理信息数据库建立、矢量化编辑、小班数据输入、制图版面设计等方法和步骤,探索ArcGIS地理信息系统与其它制图软件的相互转换方法,为推广ArcGIS地理信息系统在林业专题图制作中的应用,展望现代数字林业模式与前景。     

The use of delayed gadolinium enhanced magnetic resonance imaging of cartilage and T2 mapping to evaluate articular cartilage in the normal canine elbow

Commonly used diagnostic tools used to evaluate articular cartilage lack the sensitivity, specificity, and objectivity to measure early changes associated with osteoarthritis. Two techniques using magnetic resonance (MR) imaging have been developed to detect the biology of articular cartilage are delayed gadolinium-enhanced MR imaging of cartilage (dGEMRIC) and T2 mapping. Both techniques have been validated and are used to study the degenerative and adaptive nature of articular cartilage in people. The use of these techniques as a diagnostic tool in dogs has not been well described. We evaluated articular cartilage in the region of the medial coronoid process (MCP) of six healthy dogs free of detectable orthopedic disease using both MR imaging techniques. Histology and proteoglycan (PG) content of the MCP were used to confirm normal articular cartilage. All dogs had ground reaction forces consistent with normal function. Mean dGEMRIC index (T1 value) was 400 +/- 47 ms and mean T2 value was 56 +/- 8 ms. Intra- and interobserver variability was low. dGEMRIC and T2 values for normal cartilage in the elbow of the dog can be generated reproducibly using 3T MR imaging. Using these techniques as objective outcome measures for clinical studies in dogs with OA conditions should help delineate the efficacy of some disease interventions.     

基于个性化服务的数字图书馆知识服务研究

将个性化服务作为数字图书馆知识服务实施的一个切入点进行阐述,介绍了国内外个性化知识服务的成功案例,针对我国现行数字图书馆知识服务的状况,分析了数字图书馆知识服务实施中存在的问题,并提出了相应的解决对策。