Accuracy of pairwise methods in the reconstruction of family relationships, using molecular information from turbot (Scophthalmus maximus)

Many estimators and algorithms have been developed to infer the genealogical relationships from molecular marker data when there is no pedigree information. Most pairwise methods provide estimates in a continuous range that needs to be converted into genealogical relationships (namely full-sibs, half-sibs and unrelated) if there is a previous knowledge of the population structure. Transformations are usually based on arbitrary thresholds, but the possibility of correcting the coancestry estimates via explicit pedigree reconstruction methods has been suggested. Using molecular data for ten highly polymorphic microsatellite loci on a population of turbot (Scophthalmus maximus) with a known genealogy, the behaviour of four pairwise marker-based coancestry estimators and the molecular coancestry has been evaluated. The population consisted on 138 families with 4 full-sib individuals each and one family with 8 full-sib individuals (up to 15 half-sib families were also present due to the sharing of parents between some of the full-sibs families). Our results suggested that transforming the pairwise estimators and the molecular coancestry to family relationships through the establishment of thresholds performs slightly better than the explicit pedigree reconstruction method, when accuracy is measured in a pairwise basis. However, if joint relationships between more than two individuals were tested at a time, the threshold methods led to a high percentage of incongruous triads of full-sib individuals, with Mendelian incompatibilities appearing in congruous full-sib families (more than 70% and 60% in our study, respectively). The explicit pedigree reconstruction approach, due to its nature, is free from such problems. Therefore, the pedigree reconstruction approach seems to be a valuable tool to provide a congruent and compatible pedigree when the pairwise marker-based coancestry matrices or the molecular coancestry need to be transformed.     

几种养殖扇贝微卫星标记的研究进展

我国扇贝养殖规模占世界首位,栉孔扇贝( Chlamys farreri ) 、华贵栉孔扇贝( Chlamys nobilis ) 、虾夷扇贝( Patinopecten yessoensis) 和海湾扇贝( Argopecten irradians ) 是4 种主要养殖扇贝种类。本文主要概述我国4种主要养殖扇贝微卫星标记开发现状以及在遗传多样性分析、遗传图谱构建、物种鉴定等方面取得的研究成果和应用进展,为微卫星标记在扇贝类遗传学研究提供基础资料。     

大黄鱼22个微卫星标记在F1家系中的分离方式及与生长性状的相关分析

研究了1个大黄鱼F1家系150个个体22个微卫星位点的基因型分布,并分析了标记位点与生长性状的相关性。结果显示,22个位点共检测到60个等位基因,平均等位基因数为2.73,平均有效等位基因数为2.37;平均观测杂合度与期望杂合度分别为0.75和0.73,部分位点基因型分布严重偏离孟德尔定律,暗示其可能与适应性基因相连锁,其中LYC0446位点附近可能存在隐性纯合致死基因。LYC0077位点与体质量、体长和体高均呈显著相关(P<0.05),其中等位基因A(165 bp)对应的生长性状表型值最大,可以作为选育快长性状的有效分子标记;LYC0015和LYC0243与体高呈显著相关(P<0.05),与体长、体质量的相关不显著(P>0.05),LYC0015位点的等位基因C(110 bp)和LYC0243位点的等位基因A(160 bp)为有利的等位基因。对LYC0015、LYC0077和LYC0243进行不同基因型个体表型值的多重比较,找到3种对生长性状有利的基因型,分别为BC、AA和AB。同时,以体质量性状为参照,对3个位点不同基因型组合进行比较,找到一个最优基因型组合(BC/AA/AB),与3个位点单独分析对应的最优基因型完全一致,符合加性作用模型。     

棕榈科植物育种研究的现状及展望

分析了棕榈科植物育种的目标,阐述了目前育种中主要应用的几种育种方法,探讨了分子育种在棕榈科植物中的应用现状,提出了加强分子育种的研究与常规育种相结合,加快新品种的培育。     

分子标记及在核心种质中的应用进展

介绍分子标记的概念和种类,并从3个方面介绍分子标记在核心种质构建中的应用进展。     

分子标记在兰花遗传育种中的研究进展

综述了RFLP、RAPD、SCAR、ISSR、SRAP、AFLP、SSR等分子标记的基本原理和主要特点,从遗传多样性分析、亲缘关系研究、种质资源鉴定、遗传图谱构建与辅助选择育种等方面介绍了分子标记在兰花遗传育种工作中的现状及其研究进展,并提出展望。     

外源总DNA直接导入植物的分子育种研究进展

文中介绍了2种较常用的外源总DNA直接导入植物的方法—花粉管通道法和离子束介导法,分别从原理与方法、发展与应用、机理与验证、问题与展望4个方面综述了这2种方法的创立与发展以及应用此方法取得的研究成果。     

调控左右不对称模式建成的分子机制研究进展

器官左右不对称模式发生的内在分子调控机制极其复杂。综述了近年来4种经典分子信号途径在调控组织器官不对称发育中的作用及分子调控机制。     

云南地方香稻与非香稻遗传多样性比较

1材料与方法 1．1材料 供试水稻种子全部来自于云南省农业科学院种质资源保存库,是否为香稻品种均依据保存目录的性状记载、并采用咀嚼法对其进行再次验证。其中香稻10份,非香稻45份（表见第57页Table 1：品种及其来源）。供试所有香稻和非香稻品种均具有不同的云南省种质资源保存库编号。特别是10份香稻品种,来自于云南的5个相距较远的地方,在云南栽培香稻中具有一定代表性。     

植物耐盐生理及分子机制的研究

从耐盐生理和耐盐分子机制2个方面对近年来相关的研究进行了综述。