全基因组选择育种策略及在水产动物育种中的应用前景

全基因组选择的概念自2001年由Meuwissen等提出后便引起了动物育种工作者的广泛关注.目前,澳大利亚、新西兰、荷兰、美国的研究小组已经应用该方法进行了优质种牛的选择育种,并取得了很好的效果.此外在鸡和猪的选择育种中也有该方法的应用,但在水产动物选育中尚未见该方法使用的报道.本文对“全基因组选择育种”的概念和提出背景进行了归纳,对全基因组选择育种的优势进行了阐述,并详细介绍了其具体的策略,总结了目前全基因组育种所广泛采用的方法以及取得的成果,旨在为该方法在水产动物育种方面的应用研究提供科学参考.     

水稻半外卷叶突变体sol1的表型分析与基因定位

适度卷曲有利于提高水稻叶片的光合效率,增加植株光合产物的有效积累量。我们利用甲基磺酸乙酯(EMS)处理籼型水稻保持系西农1B,获得一个稳定遗传的水稻半外卷叶突变体。该突变体从十叶期开始各叶片逐渐向外卷曲直至半卷状,并伴随茎秆半矮化和叶片披垂,暂被命名为semi-outcurved leaf 1 (sol1)。与野生型(WT)相比, sol1的叶片卷曲指数均达到30%以上(P<0.01);倒一、倒二、倒三、倒四节节间长度和穗长极显著缩短,倒一、倒二、倒三叶的叶夹角显著或极显著增加;有效穗数、千粒重、每穗实粒数、结实率显著或极显著下降,一次枝梗数则增加11.3%(P<0.05)。sol1的蒸腾速率、胞间CO2浓度、气孔导度显著高于野生型。石蜡切片显示, sol1倒一叶的泡状细胞体积变小,数量显著增多,表皮细胞体积略微增大。遗传分析表明, sol1的半外卷叶性状受1对隐性核基因调控,定位于6号染色体标记JY6-3和JY6-10之间165kb的物理范围内,共含15个注释基因。qRT-PCR结果表明,与泡状细胞相关的内卷基因和外卷叶基因RL14、Roc5、REL1在突变体sol1中呈...     

Identification and Molecular Mapping of the RsDmR Locus Conferring Resistance to Downy Mildew at Seedling Stage in Radish (Raphanus sativus L.)

Downy mildew (DM), caused by the fungus Peronospora parasitica, is a destructive disease of radish (Raphanus sativus L.) worldwide. Host resistance has been considered as an attractive and environmentally friendly approach to control the disease. However, the genetic mechanisms of resistance in radish to the pathogen remain unknown. To determine the inheritance of resistance to DM, F₁, F₂ and BC₁F₁ populations derived from reciprocal crosses between a resistant line NAU-dhp08 and a susceptible line NAU-qtbjq-06 were evaluated for their responses to DM at seedling stage. All F₁ hybrid plants showed high resistance to DM and maternal effect was not detected. The segregation for resistant to susceptible individuals statistically fitted a 3:1 ratio in two F₂ populations (F_2(SR) and F_2(RS)), and 1:1 ratio in two BC₁F₁ populations, indicating that resistance to DM at seedling stage in radish was controlled by a single dominant locus designated as RsDmR. A total of 1972 primer pairs (1036 SRAP, 628 RAPD, 126 RGA, 110 EST-SSR and 72 ISSR) were screened, and 36 were polymorphic between the resistant and susceptible bulks, and consequently used for genotyping individuals in the F₂ population. Three markers (Em9/ga24₃₇₀, NAUISSR826₇₀₀ and Me7/em10₄₀₀) linked to the RsDmR locus within a 10.0 cM distance were identified using bulked segregant analysis (BSA). The SRAP marker Em9/ga24₃₇₀ was the most tightly linked one with a distance of 2.3 cM to RsDmR. These markers tightly linked to the RsDmR locus would facilitate marker-assisted selection and resistance gene pyramiding in radish breeding programs.     

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.     

基于植被覆盖率的农村居民点整理潜力估算及实证

为合理估算农村居民点整理潜力,该文提出基于植被覆盖率的农村居民点整理潜力测算新思路。借助植被覆盖率对农村居民点斑块进行分类,通过分析抽样农村居民点斑块的植被覆盖与内部用地结构得到整理潜力修正系数,从而建立基于植被覆盖率修正的农村居民点整理潜力估算模型,并以北京市门头沟区为例展开实证研究。研究结果表明,门头沟区无整理潜力的农村居民点占大多数,具有整理潜力的农村居民点主要集中在经济相对落后的乡镇,并且这部分农村居民点多远离主干道;山区具有中、高整理潜力的农村居民点略多于平原、浅山区,而低整理潜力的农村居民点明显多于平原、浅山区;门头沟区规划整理的农村居民点内部包含有大量农用地,其中建设用地比例只占63.19%～71.54%,但是,第二次土地调查将整个农村居民点都作为建设用地调绘;因而,一些不考虑植被覆盖修正的农村居民点整理潜力测算方法夸大了整理潜力,放大了城乡建设用地增减挂钩的效果。该文为进一步合理估算农村居民点整理理论潜力提供参考。     

低磷胁迫下大豆主要农艺性状的QTL定位

利用来自铁一7555(耐低磷种质)和凤59-15的重组自交系群体(110个家系),通过盆栽试验研究与耐低磷有关的性状,并进行耐低磷性状的QTL定位.对所调查的相对株高、相对根系干质量、相对叶中磷含量和相对根系磷含量4个性状进行分析,结果表明,在N和O两个连锁群上共检测到3个QTL与耐低磷有关.分别可解释所对应性状表型变异的4.84%～18.2%,其中2个QTL的增效基因来自亲本铁-7555,1个QTL的增效基因来自亲本凤59-15.     

Revisiting two sympatric European seahorse species: apparent decline in the absence of exploitation

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玉米粒重一致性QTL整合图谱的构建及元分析

为进一步研究候选基因发掘、克隆以及基因组结构,在生物信息学基础上,利用公共网络资源上已发表的149个玉米粒重相关QTL位点信息,初步探讨了玉米粒重一致性QTL发掘。结果表明:构建出一个包含了80个玉米粒重QTL位点的整合图谱,并在第7染色体上确定出一个一致性QTL,由标记bcd349和gpm760a界定,置信区间为463.29~505.50,间距42.21cM。     

QTLs for Waterlogging Tolerance at Germination and Seedling Stages in Population of Recombinant Inbred Lines Derived from a Cross Between Synthetic and Cultivated Wheat Genotypes

Waterlogging is a widespread limiting factor for wheat production throughout the world. To identify quantitative trait loci （QTLs） associated with waterlogging tolerance at early stages of growth, survival rate （SR）, germination rate index （GRI）, leaf chlorophyll content index （CCI）, root length index （RLI）, plant height index （PHI）, root dry weight index （RDWI）, shoot dry weight index （SDWI）, and total dry weight index （DWI） were assessed using the International Triticeae Mapping Initiative （ITMI） population W7984/Opata85. Significant and positive correlations were detected for all traits in this population except RLI. A total of 32 QTLs were associated with waterlogging tolerance on all chromosomes except 3A, 3D, 4B, 5A, 5D, 6A, and 6D. Some of the QTLs explained large proportions of the phenotypic variance. One of these is the QTL for GRI on 7A, which explained 23.92% of the phenotypic variation. Of them, 22 alleles from the synthetic hexaploid wheat W7984 contributed positively. These results suggested that synthetic hexaploid wheat W7984 is an important genetic resource for waterlogging tolerance in wheat. These alleles conferring waterlogging tolerance at early stages of growth in wheat could be utilized in wheat breeding for improving waterlogging tolerance.     

流域尺度土壤厚度的模糊聚类与预测制图研究

基于土壤厚度与景观位置和特征之间的关系,运用模糊c均值聚类(FCM)方法对西苕溪流域的土壤厚度分布进行了空间预测。选取高程、坡度、平面曲率、剖面曲率、径流强度系数和地形湿度指数6个地形因子进行模糊聚类,根据相应的聚类参数将流域地形组合分为8类。利用部分调查获得的土壤剖面数据,结合样点属性和专家经验为典型区赋值,最后由加权平均得到流域土壤厚度预测图。验证结果表明,FCM方法可以对地形因子组合进行有效合理的分级,其预测精度较高,模型的稳定性较好,是一种低成本高效率的制图方法。该方法在土壤厚度预测方面具有一定的可靠性。