利用SSR标记分析19份山羊草属种D基因组遗传多样性

具有D染色体组的山羊草属种是六倍体普通小麦的二级基因源,蕴藏着丰富的抗性基因和遗传变异丰富,可供现代小麦改良利用。选用24对D染色体组特异性微卫星(SSR)标记引物,将19份山羊草属种的D染色体组与3个普通小麦的D染色体组的遗传多样性进行了比较分析。共检测出679个等位基因,每个SSR位点上能检测到1~44个等位基因,平均28.29个。聚类分析结果表明,同一属种的材料基本上聚为一类,19份山羊草属种的D染色体组与普通小麦的D染色体组之间存在较大的遗传差异,可供小麦远缘杂交以丰富栽培小麦遗传多样性。     

一种节节麦高分子量麦谷蛋白与小麦同源蛋白氨基酸序列的比较

对节节麦的一种y类高分子量麦谷蛋白基因进行了序列测定和比较。结果显示,该亚基与小麦A、B和D和节节麦D染色体编码的y型亚基的全蛋白氨基酸残基数目均不一致。6个y型基因的信号肽、N-端和C-端氨基酸残基数目均一致,但有个别氨基酸的替换。而重复区氨基酸残基数目均不一致,主要由于重复单元六肽和九肽的数目不等。在目前已知的D基因组编码的y型亚基中,Dy13t的重复区是最短的,它比Dy10少4个九肽,比Dy12少4个九肽,2个六肽,比Dy12t少4个九肽。由N-Calign序列所作的聚类分析将这6个y型亚基分为3支,A、B和D基因组编码的亚基各占一支。来源于D基因组的4个基因的一支,又可将来源于节节麦和小麦D基因组的2个基因分别聚类在一起。     

普通小麦与山羊草叶绿体基因组长度热点突变区的核苷酸序列分析

 检测了Ae. speltoides和Ae. ovata叶绿体基因组的一个长度热点突变区的核苷酸序列，并与普通小麦、四倍体Ae. crassa 以及Ae. squarrosa的相应序列进行了比较分析。从rbcL基因的终止密码子到cemA基因内的HindIII位点，Ae. speltoides和Ae. ovata的核苷酸序列长度分别为2 808 和 2 810bp。与四倍体Ae. crassa的序列相比，在普通小麦和Ae. speltoides中各有一个791 bp的大片段缺失，在Ae. ovata中存在一个793 bp的大片段缺失。Ae. ovata的缺失片段比普通小麦和Ae. speltoides的长2个碱基，推测Ae. ovata的大片段缺失在进化上是独立发生的。Ae. speltoides的大片段缺失与普通小麦的完全相同，支持Ae. speltoides是普通小麦叶绿体基因组供体的假说。除了大片段缺失外，在这个区域还检测到了7 个插入/缺失和15个碱基替换突变。研究结果表明，这个长度热点突变区的核苷酸序列分析是研究小麦与山羊草叶绿体基因组之间遗传变异关系的一个非常有效的途径。     

节节麦抗穗发芽基因的染色体定位及其抗性机理

 利用长休眠的河南节节麦与四倍体小麦矮兰麦杂交并经人工加倍合成的新六倍体小麦RSP,其节节麦抗穗发芽特性得到表达。通过对RSP不同灌浆期及不同发芽处理研究表明,在开花后35d的穗发芽高峰期其发芽率也仅为6.06％。其抗穗发芽的因素主要来自种子的抑制,麦穗的机械作用和颖壳内含物的抑制较次。利用RSP对节节麦的抗穗发芽基因进行定位分析,结果表明,RSP的抗穗发芽基因是隐性单基因位于2D染色体上。     

钩刺山羊草(Aegilops triuncialis)低分子量谷蛋白基因序列分析

根据低分子量谷蛋白亚基(LMW-GS)基因编码区保守序列设计引物,对钩刺山羊草(AegilopstriuncialisL,2n=4x=28,CCUU)PI483029总DNA进行PCR扩增,得到长度为900和1065bp的DNA片段,克隆测序后获得2个LMW-GS基因,GenBank登录号分别为AY841016和AY841017。它们具有小麦LMW-GS基因的典型结构特征。其中,AY841017具有完整编码区,长度为1065bp,可编码322个氨基酸残基的成熟蛋白,第一个半胱氨酸残基出现在重复区第13位。在重复区,AY841017的两个疏水单元为PIIIL和PVIIL,重复区中还存在一个连续13个Q(谷氨酰胺)组成的短肽。AY841016由于编码区内存在提前终止密码子,为假基因。氨基酸序列比较发现,AY841017与普通小麦(IriticumaestivumL.)Glu-D3位点编码的LMW-GS基因有很高的一致性。     

抗条锈、抗穗发芽六倍体人工合成小麦Cereta/Aegilops tauschii783的SSR标记分析

Cereta/Aegilops tauschii783是由CIMMYT引进的硬粒小麦/节节麦人工合成种,具有高抗条锈和高抗穗发芽等优良特性.本文选用小麦A、B、D染色体组的91对SSR引物将人工合成小麦Cereta/Aegilops tauschii783与绵阳26在分子水平上进行了比较分析,结果表明：91对引物中有88对引物能扩增出清晰条带;88对引物中除3对引物外,86对引物（96.59%）均能揭示出Cereta/Aegilops tauschii783与绵阳26之间的差异.人工合成小麦Cereta/Aegilops tauschii783与育成小麦品种遗传差异很大,是丰富现代小麦遗传多样性的优异基因源;利用人工合成小麦Cereta/Aegilops tauschii783与绵阳26构建SSR标记群体,可有效标记双亲优良基因.     

Phenotypic responses of the wild wheat relative Aegilops geniculata Roth and wheat (Triticum durum Desf.) to experimentally imposed salt stress

In order to study the salt effect on the wild wheat and durum wheat, three accessions of Aegilops geniculata L. from Ain zana, Zaghouan, and Sbitla and one variety of wheat (Triticum durum L.) have been grown in the INRAT green house and treated with different salt concentrations. The morphological, phenological and yield characters have been measured for each plant and analyzed using SAS software. This study has shown a high degree of variation of these characters mainly related to geographical origin. It was observed also that Sbitla accession was less affected by the imposed salt stress than all the others while Ain zana was the most affected one.     

不同作物秸秆腐解液对节节麦种子萌发和幼苗生长的影响

节节麦(Aegilops tauschii Coss.)作为麦田恶性杂草之一,给中国小麦生产带来了严重的经济损失。为探究农作物秸秆在节节麦生态防治方面的作用,本试验采用了滤纸培养皿法和小杯法研究了不同浓度的玉米、油菜、水稻秸秆及稻壳腐解液对节节麦种子萌发率、发芽指数及幼苗根长、苗高和干重5项生物指标的影响。结果表明,当浓度为6.25 mg/mL时,玉米、油菜秸秆腐解液对节节麦幼苗干重表现为促进作用,对其他测定指标均为抑制作用。稻壳腐解液除了对根长具有抑制作用外,对其他指标均具有促进作用。水稻秸秆腐解液对5项指标均具有促进作用。当浓度大于50 mg/mL时,4种秸秆腐解液对5项指标均具有抑制作用,且随着浓度的增加,抑制作用增强。总体来说,作物秸秆腐解液对节节麦的化感作用强弱依次为玉米秸秆、油菜秸秆、稻壳、水稻秸秆,且对根的化感作用尤为明显。     

Variation for apparent amylose content of endosperm starch in Triticum durum and Aegilops squarrosa

For breeding to increase amylose content in the starch of hexaploid wheat, either the introduction of genes from Aegilops squarrosa (DD genome) or the development of high-amylose amphiploids between Triticum durum (AABB genome) and Ae. squarrosa is one of the most efficient ways. The high-amylose genes have not been detected in any species of Triticum and Aegilops. Therefore, we assessed the apparent amylose content in endosperm starch of T. durum and Ae. squarrosa accessions supplied from the major gene banks from world wide, and found several accessions with higher amylose content out of 665 T. durum accessions and out of 732 Ae. squarrosa accessions. Genetic analysis indicated that a high amylose trait in Ae. squarrosa is monogenically inherited by a recessive major gene. This revised version was published online in July 2006 with corrections to the Cover Date.     

Identification of a new family of tandem repeats in Triticeae genomes

A new family of cereal tandem repeats was isolated, characterised and designated as spelt-1. The family of repeats comprises about 2% of the Aegilops speltoides genome; however, its content differs considerably in the genomes of various Triticeae species. Copy number of the constituent sequence, relative to Ae. speltoides, proved to be 40-60 times reduced in the genomes of tetraploid wheats, 400-fold reduced in the genome of Triticum monococcum, and 1200-2400 times in the genomes of the other 19 Triticeae species studied. Drastic difference in the copy number and homology extent of the spelt-1 family sequences between Ae. speltoides and other diploid species allows the utilisation of these sequences as species-specific telomeric markers for Ae. speltoides, provided stringent hybridisation conditions apply. RFLP (restriction fragment length polymorphisms) analysis of spelt-1 reveals polymorphism between the above species. This study of spelt-1 organisation in different Triticum species provided further substantiation of the polyphyletic origin of the B genome of polyploid wheat. This revised version was published online in August 2006 with corrections to the Cover Date.