小麦K-CMS保持系的SRAP鉴定及遗传多样性分析

为更好地对小麦K-CMS保持系的遗传背景进行分析,筛选优良亲本,以进一步提高小麦杂交育种的效率。利用SRAP技术,对30份小麦K-CMS保持系的遗传背景进行研究,以SRAP标记在30个品种之间扩增的多态性位点数据,采用Nei和Li的方法,计算品种间的遗传距离;以2年田间试验得到的品种株高、穗长、小穗数、穗下节长、穗粒草重、穗粒数、穗粒重、旗叶长等表现型性状平均数经正态标准化后,采用欧氏距离计算品种间遗传距离,再比较分析。分析表明,82对SRAP引物揭示出多态性,多态率68.3%,获得208条多态性谱带,平均每对引物产生3.68条多态性谱带,表现出较高的多态性。基于分子标记的聚类分析结果与系谱分析结果基本一致。若以整个遗传距离的总平均数作尺度对聚类图的结果进行分类,大致可分为6类。Mantel检测表明,SRAP标记数据计算的遗传距离矩阵和表现型计算的遗传距离矩阵存在极显著的相关性0.8123(t=11.325t0.01)。SRAP标记是检测品种间遗传差异的有效方法,可为小麦K-CMS保持系种质资源遗传差异的研究提供理论依据。研究还证实,一个骨干亲本与由其衍生出来的品种(系)之间的遗传差异一般较小。     

Assessment of wheat variety stability using SSR markers

In International Union for the Protection of New Varieties of Plants member countries, assessment of wheat variety stability is a statutory requirement before new varieties are registered and plant breeders’ rights are granted. However, it is impossible to test the stability of varieties accurately and quickly, or to assess the stability of a large number of varieties in a short time based on the morphological traits defined by the national standard. The objective of this study was to establish method and procedure of wheat variety stability assessment using SSR markers as a replacement for morphological observations. In preliminary study, the methods to identify non-homozygous SSR loci and calculate the homozygous SSR loci ratio (SSR–HLR) of wheat varieties were established. On this basis, the genotypes at 347 molecular markers loci of 20 advanced lines demonstrated that SSR–HLRs were 84.7–94.8 % in the F₄ lines, 96.1–99.4 % in the F₅ lines, and ≥98 % in the F₆ lines, respectively. Eighty of 347 markers with good polymorphism, stable PCR amplification, and high resolving power of genotyping were recommended to detect SSR–HLR for 633 wheat regional trial varieties. Comparing morphological observation, the varieties with SSR–HLR >95 % were deemed stable; the varieties with SSR–HLR <91 % were deemed unstable; the varieties with SSR–HLR ranging from 91 to 95 % were required field identification for stability assessment. Based on the relationship between the homozygous SSR loci ratio and wheat variety stability, procedures for the assessment of wheat variety stability using SSR markers were established.     

小麦区试品系DUS测试的分子标记

为了确定测试小麦(Triticum aestivum L.)区试品系特异性、一致性、稳定性(DUS)的分子标记,采用156个来自我国不同麦区的品种对SSR、EST-SSR和AFLP-SCAR标记的1334对引物进行筛选,根据在染色体上分布均匀、多态性信息指数较高、带型清晰、不同等位变异的带型易于区分及PCR产物稳定的原则,筛选出105对小麦品种DUS测试的分子标记引物,包括63对SSR引物、21对EST-SSR引物和21对AFLP-SCAR引物,可以检测122个位点的754个等位变异,平均每条染色体上被检测位点5.8个,平均每个位点包含7.2个等位变异。根据DUS测试的需求、引物的染色体分布、PIC值大小和带型特点,将105对引物分为21对核心引物、29对一级备用引物和55对二级备用引物。核心引物分辨力较高,可以完成约80%品系的特异性检测,约95%品系的种子纯度检测和约60%品系的一致性、稳定性检测;备用引物用于确定品系DNA位点纯合率和相似品种(品系)之间的遗传相似系数,以判断DNA指纹相同或相似的品种(品系)之间的相似性和特异性,评价核心标记中具有非纯位点的品系的DNA位点纯合度,同时完成核心引物未能完成的少数品系的种子纯度检测。通过在2006-2007、2007-2008、2008-2009年度对464个冬小麦区试品系DUS测试中的应用,证明105对引物具有很好的代表性和实用性,可以完成90%以上参试品系的DUS检测。     

利用SSR标记进行优质冬小麦品种(系)的遗传多样性研究

遗传多样性研究对于作物育种具有重要意义. 选择分布于21条小麦染色体上的59对SSR引物对48个优质冬小麦新品种(系)进行了遗传多样性分析. 共检测出209个等位位点, 每对引物等位位点数在2～9之间, 平均为3.5个. 位点多态性信息含量PIC变幅为0.16～0.87, 平均0.56. 8个引物组合在一起可将全部品种区分开来, 48个品种可分为五类,     

利用分子标记筛查小麦相似品种(系)

在每年的小麦区域试验中均发现一些参试品系高度相像或与审定品种高度相像,为此需建立从大量品种中筛查相似品种的方法。本文比较了547个国家冬小麦区域试验品系及134个国审品种的分子标记遗传相似系数(GS)和主要农艺性状及表型,发现绝大多数相似品种(系)间的GS大于0.90,依此确立了用分子标记筛查相似品种的方法体系,解决了无法从大量品种中查找相似品种(系)的问题。     

Genetic diversity of hexaploid wheat cultivars estimated by RAPD markers, morphological traits and coefficients of parentage

Estimates of genetic diversity can be based on different types of data. The aim of this research were to study genetic diversity among Croatian wheat cultivars by random amplified polymorphic DNA (RAPD) markers, morphological traits and pedigree records; to analyse differences between wheat cultivars from two breeding centres; and to evaluate usability of RAPD markers for estimation of genetic diversity among wheat cultivars in comparison with morphological traits and pedigree record data. Studies were conducted on 14 wheat cultivars and breeding lines from two breeding centres in Croatia. For the RAPD analysis 36 primers were screened and the 14 most polymorphic ones yielded 341 polymorphic bands. Twelve morphological traits were used for morphological analysis. Pedigrees were composed of seven generations of ancestors. RAPD markers showed a high level of polymorphism among the cultivars examined and the breeding lines. No significant correlations were observed among the methods tested.     

Molecular markers and protein quantities as genetic descriptors in maize. II. Prediction of performance of hybrids for forage traits

As it is related to the variability in genome expression, variability in protein quantities revealed by two-dimensional electrophoresis was proposed for describing phenotypic diversity. The objective of this study was to compare the predictive power of different genetic distances derived from molecular markers and from protein quantitative variations in a diallel of 210 hybrids among 21 maize inbred lines (Zea mays L.) of various origin. The lines were characterized for: 1. 142 markers resulting from the analysis of enzyme, RFLP, and protein-structure polymorphism; and 2. The variation in relative quantities of 190 proteins. The hybrids were evaluated for six forage traits in four environments. Correlations between the genetic distances computed for 142 marker loci and hybrid performances were moderate to high in diallels using crosses between related lines. Genetic distances based on protein quantities showed, in most cases, similar or lower correlations. Distance measures were not useful as predictors of hybrid performance for crosses between unrelated lines. Protein quantities were better for revealing specific genotypes.     

1950年以来山东省主推小麦品种的遗传多样性演变

利用24对SSR引物对62个山东省1950年以来大面积推广小麦品种遗传多样性的演变情况进行了分析。结果表明24对引物均有较好的多态性,共扩增到100个等位变异片段(等位基因),平均每个标记获得4.167个等位基因,多态性信息量(PIC)值平均为0.527,变幅0.200～0.723,基因多样性指数变幅0.225～0.761,平均0.582。三个基因组的位点多态性存在明显差异,平均等位变异丰富度D>B>A,基因多样性指数和多态性信息指数B、D基因组接近,并明显高于A基因组。山东省小麦品种平均遗传丰富度、遗传多样性指数和平均遗传距离均以50年代较高(分别为3.042,0.531和0.596),然后缓慢下降,1980年代回升到顶峰(分别为3.250,0.560和0.616),然后迅速下降。62个品种遗传相似系数变幅为0.580～0.940,平均为0.723。按非加权类平均法(UPGMA)、在遗传相似系数0.719处将不同品种聚类成7类,基本与山东省不同时期育种骨干亲本及其衍生品种一致,说明山东省近60年来小麦育种与全国一样,围绕骨干亲本展开。由于特有种质资源的创造和应用,山东省小麦品种遗传多样性高于全国和其他麦区,尤其是1980年代,但之后迅速下降,必须引起足够重视。     

Genetic analysis of bread-making quality in wheat and spelt

Bread‐making quality in wheat and spelt reflects the combination of several, mostly quantitatively inherited parameters. The aim was to find molecular markers linked to quantitative trait loci (QTL) for quality parameters. Zeleny sedimentation values (Zel), protein (Prot), kernel hardness (KH) and 1000‐kernel weight (TKW) of 226 F₅ recombinant inbred lines (RILs) from a cross between wheat and spelt were assessed in different environments. The dough properties of 204 RILs were assessed with an alveograph. Based on a genetic map of 187 loci, nine QTL were found for Zel and Prot, explaining 47% and 51% of the phenotypic variance, respectively. Fifty‐four per cent of the variance was explained by 10 QTL for KH and eight for TKW. For the alveograph parameters 10 QTL were found for baking strength, nine for tenacity, seven for configuration ratio, and four for elasticity index and extensibility. The phenotypic variance explained ranged from 25% to 48%. The population mean of the dough parameters was shifted towards the spelt parent. It is concluded that non‐additive effects are crucial in the expression of high bread‐making quality of wheat. The consequences for wheat and spelt breeding programmes are discussed.     

小麦三雌蕊近等基因系的麦谷蛋白和醇溶蛋白分析

为充分利用小麦三雌蕊近等基因系的优良性状,深入探索其在小麦遗传育种中的利用价值。采用聚丙烯酰胺凝胶电泳技术,对小麦三雌蕊近等基因系的高分子量麦谷蛋白(HMW-GS)、低分子量麦谷蛋白(LMW-GS)和醇溶蛋白进行了分析。以‘中国春’(CS)为参照,按照LMW-GS和醇溶蛋白电泳图谱条带迁移距离大小和条带多态性对供试材料进行聚类分析。麦谷蛋白的SDS-PAGE电泳结果表明,10份材料共出现了10 种HMW-GS 亚基类型和8 种亚基组合;在Glu-A1 位点,主要亚基Null 的频率达60%;Glu-B1 位点,主要亚基7+8 的频率为50%;Glu-D1 位点,主要亚基2+12 的频率为60%;主要亚基组合为Null/7+8/2+12。10 份材料共分离出20 条LMW-GS带谱,其中共有带谱10 条,比例为50%。醇溶蛋白的A-PAGE电泳结果表明,10 份材料共分离出25 条带谱,其中共有带谱5 条,比例为20%。聚类分析结果表明,10 份材料的遗传距离为0.03~0.28,当遗传距离为0.26 时,10 份材料可分为3 大类。综合麦谷蛋白和醇溶蛋白分析以及聚类分析结果可知,小麦三雌蕊近等基因系不能用于提高小麦的品质育种,但可用于提升小麦的产量育种,其首要目标是提高千粒重。     

小麦EST-SSR标记的开发和染色体定位及其在追踪黑麦染色体中的应用

根据小麦盐胁迫诱导和茎秆组织相关EST序列开发了81对EST-SSR引物, 其中67、46、18和61对分别在小麦、黑麦、簇毛麦和大麦基因组中稳定扩增, 在不同小麦和大麦品种间具有多态性的引物分别有22和23对。利用小麦缺体-四体系共定位了43对引物的81个位点, 其中A、B和D染色体组上分别有29、30和22个位点, 涉及除4B、3D和6D外的18条染色体。此外30对引物在黑麦基因组中具有特异扩增, 其中8对分别在黑麦1R、4R、5R和R7染色体上具有特异扩增, 7对在多条黑麦染色体具有相同扩增。这些新标记可有效用于小麦及其近缘物种的遗传作图与比较遗传研究。     

应用RAPD标记进行茶树优异种质遗传多态性、亲缘关系分析与分子鉴别

采用RAPD分子标记技术,对茶树优异种质资源的遗传多态性、亲缘关系和分子鉴别进行了研究。结果表明,20个引物在15份优异资源中得到1050个RAPD位点,平均52．5个位点／引物,70个位点／资源。在所获得的137条可重现谱带中,8条是单态的,129条是多态的,多态性程度达94．2％;引物的多态性相对频度为0．24～0．83,总平均为0．47;遗传距离在0．16～0．62之间,平均为0．37,这可能与我国是茶树的原产地和起源中心有密切关系。RAPD数据的类平均法聚类结果显示,15份资源可划分为3个类群,从相似性系数讨论了资源间的亲缘关系。应用12个引物产生的20个特异标记的存在和11个特异的缺失,可以鉴别所有15份优异茶树种质资源。RAPD可以作为茶树优异种质资源遗传多态性、系统演化和分子鉴别研究的有效手段之一。     

罗布麻遗传多样性的AFLP分析

利用AFLP分子标记技术,对产于内蒙古通辽、包头与巴彦淖尔的罗布麻遗传多样性进行分析.用筛选出的4对适宜引物组合共扩增出5 359个AFLP位点,其中多态性位点4 889个,多态性位点比率高达91.22%;产于通辽地区的罗布麻遗传变异较大,与包头和巴彦淖尔两地的罗布麻亲缘关系较远,而包头与巴彦淖尔两地间的罗布麻亲缘关系相对较近.聚类结果与材料的来源地有一定相关性,较好地反映了不同地区间的遗传背景及亲缘关系.     

Chromosomal location of genes for resistance to powdery mildew in <Emphasis Type="Italic">Agropyron cristatum</Emphasis> and mapping of conserved orthologous set molecular markers

Agropyron cristatum exhibits resistance to Blumeria graminis f. sp. tritici. Disomic and ditelosomic chromosome addition lines of A. cristatum in ‘Chinese Spring’ wheat were utilized to determine which A. cristatum chromosomes carry resistance gene(s). Resistance is conferred by gene(s) on chromosome arms 2PL and 6PL. The availability of molecular markers capable of detecting these chromosome arms in a wheat background would be very useful for marker-assisted introgression of 2PL and 6PL chromatin into common wheat. With this aim, 170 wheat conserved orthologous set (COS) markers (92 and 78 from wheat homoeologous groups 2 and 6 respectively) were assessed for their utility in A. cristatum. A total of 116 (68.2%) COS markers successfully amplified product in A. cristatum and 46 (40.0%) of these markers were polymorphic between A. cristatum and common wheat. From marker loci mapping on wheat homoeologous group 2 chromosomes, 23 markers (34.9%) were polymorphic between A. cristatum and common wheat and from them 13 markers were assigned to chromosome arm 2PL and six markers were mapped to chromosome 4P of A. cristatum showing that this chromosome is related to wheat homoeologous group 2. From marker loci mapping on wheat homoeologous group 6 chromosomes, 23 (46.0%) markers were polymorphic between A. cristatum and common wheat and from them 17 markers were located on chromosome 6P, six of them were mapped to chromosome arm 6PS and five to chromosome arm 6PL, respectively. The specific COS markers allocated on the long arms of chromosomes 2P and 6P may have a role in marker-assisted screening in wheat breeding for powdery mildew disease resistance.     

利用关联分析发掘小麦自然群体旗叶叶绿素含量的优异等位变异

为揭示小麦自然群体干旱胁迫条件下旗叶叶绿素含量的变化, 筛选相关标记的优异等位变异, 以262份小麦种质资源组成的自然群体为材料, 分别种植在北京的2个试验地点, 均设雨养和灌溉处理, 于开花期和灌浆期检测旗叶叶绿素含量。以分布于21条染色体的169个SSR标记检测所有材料的基因型, 利用STRUCTURE 2.3.2软件分析群体结构, 用TASSEL软件的MLM (mixed linear model)方法对小麦自然群体的旗叶叶绿素含量进行关联分析。在此基础上, 将携带某等位变异的所有材料表型均值与携带无效等位基因(null allele)材料表型均值比较, 估计等位变异的表型效应, 鉴别优异等位变异。共检测到2048个等位变异, 每位点2~37个等位变异, 平均12个。每位点的标记多态性信息量(PIC)为0.008~0.936, 平均0.628。在22个标记位点共检测出40个(次)与旗叶叶绿素含量极显著的关联, 其中11个标记位点有2次以上的关联, Xwmc419-1B和Xgwm501-2B分别有3次关联。在Xcfa2123-7A、Xgwm232- 1D和Xgwm429-2B位点分别检测到效应值大于4.0的等位变异。     

普通小麦背景中长穗偃麦草[Lophopyrum elongatum(Host) A. Lve]E染色体组的RGAP特异标记

利用已知植物抗病基因编码氨基酸保守区域NBS-LRR(核苷酸结合位点-富亮氨酸区域)设计了42个简并引物组合,运用抗病基因类似物多态性(resistance gene analog polymorphism,RGAP)分子标记技术,对中国春、中国春-长穗偃麦草双二倍体及其附加系和代换系基因组DNA进行PCR扩增。结果表明,共有38对引物组合获得扩增产物,其中35对在普通小麦中国春、中国春-长穗偃麦草双二倍体中能扩增出多态性,平均每个引物组合扩增出38.5个片段。在普通小麦背景下,共获得275条长穗偃麦草E基因组多态性谱带,占扩增总谱带数的17.44%,揭示出在普通小麦背景下E基因组和普通小麦A、B、D基因组间的高丰度遗传变异。另外,利用RGAP分子标记技术,构建了一套完整的长穗偃麦草1E~7E染色体的特异RGAP标记。为小麦背景中长穗偃麦草外源遗传物质的快速检测提供了新途径。     

21种不同类型葡萄种质资源遗传多样性的SSR分析

本研究通过SSR标记解析不同类型葡萄种质遗传多样性差异和亲缘关系,为资源分类与品种鉴定提供理论依据。利用15对SSR引物对21种不同类型葡萄种质进行PCR扩增,对扩增情况、遗传距离与亲缘关系等进行分析。15对SSR引物共扩增出等位基因位点91个,其中多态性位点89个,多态性比率高达97.8%,其中13对引物扩增多态性百分率达到100%。21份供试材料间遗传相似系数变化范围在0.45~0.91之间,并在遗传相似系数0.62处被分为2个类群。研究表明SSR标记从分子水平上解析了不同类型葡萄种质的遗传差异性,揭示了材料间亲缘关系,为育种研究提供了一定参考依据。     

普通小麦背景中长穗偃麦草[Lophopyrum elongatum (Host) A. Löve]E染色体组的RGAP特异标记

利用已知植物抗病基因编码氨基酸保守区域NBS-LRR（核苷酸结合位点-富亮氨酸区域）设计了42个简并引物组合，运用抗病基因类似物多态性（resistance gene analog polymorphism，RGAP）分子标记技术，对中国春、中国春-长穗偃麦草双二倍体及其附加系和代换系基因组DNA进行PCR扩增。结果表明，共有38对引物组合获得扩增产物，其中35对在普通小麦中国春、中国春-长穗偃麦草双二倍体中能扩增出多态性，平均每个引物组合扩增出38.5个片段。在普通小麦背景下，共获得275条长穗偃麦草E基因组多态性谱带，占扩增总谱带数的17.44%，揭示出在普通小麦背景下E基因组和普通小麦A、B、D基因组间的高丰度遗传变异。另外，利用RGAP分子标记技术，构建了一套完整的长穗偃麦草1E~7E染色体的特异RGAP标记。为小麦背景中长穗偃麦草外源遗传物质的快速检测提供了新途径。     

Discriminating durum wheat cultivars using highly polymorphic simple sequence repeat DNA markers

The winter type durum wheat varieties of Anatolia used in this study were differentiated for the first time by using simple sequence repeat (SSR) DNA markers or microsatellites. Seven microsatellite markers were used to distinguish four well‐adapted landrace selections, five cultivars and seven recently obtained advancing lines. The loci of seven microsatellites were all homozygous, but the WMS6 locus occurred with two alleles in all the genotypes. The genotypes were all distinguished from each other, with the number of alleles ranging from five to 13. The lowest and highest polymorphism information content (PIC) values were observed to be 0.609 and 0.872, respectively. Three markers alone, WMS6, WMS30 and WMS120, can distinguish all 16 genotypes. UPGMA dendogram, based on a similarity matrix by a simple matching coefficient algorithm, is in accordance with the available pedigree information.     

Genetic diversity within Australian wheat breeding programs based on molecular and pedigree data

124 wheat cultivars and breeding lines were screened with 19 microsatellite (SSR) loci generating 160 scorable bands which were used to construct a genetic distance (GD) matrix. A distance matrix based on coefficient of parentage (COP) scores was also generated for the cultivars for which good pedigree records were available. The SSR and COP data for 101 of the wheat cultivars were compared with genetic distance scores obtained using1898 scorable restriction fragment length polymorphism (RFLP) bands previously generated. Phylograms were generated based on the SSR, RFLP,combined SSR and RFLP and COP data. The standardised Mantel's Z test showed that the distance matrices generated from all of the data sets were significantly correlated. Bootstrap analysis showed that, although the SSR and RFLP data were correlated, a large number of SSR loci are required for determining robust genetic relationships between large numbers of cultivars. In addition, accurate pedigree records are needed to determine genetic relatedness using COP. The molecular data were also used to determine the level of genetic variability within breeding programs and to assess the impact of the introduction of semidwarf and other germplasm. The results showed that the level of genetic diversity in Australian wheat cultivars has increased over time and that in particular, the introduction of semidwarf germplasm resulted in an increase in the overall diversity. This revised version was published online in August 2006 with corrections to the Cover Date.