河北省又取得一批农药植保类科研成果

<正>(接上期)3.粗山羊草Ae46抗叶锈基因鉴定及BAC文库构建单位名称:河北农业大学评价单位名称:河北省教育厅小麦远源亲本包括乌拉尔图小麦(A染色体供体),山羊草属(B染色体供体)和粗山羊草(D染色体供体),其中粗山羊草在小麦进化中起着重要作用,并为小麦品种改良提供了一批优良     

小伞山羊草染色体的FISH核型分析

采用荧光原位杂交(Fluorescence in Situ Hybridization,FISH)技术分析小伞山羊草染色体的核型特点。结果表明,小伞山羊草共包含7对染色体,其中1 U和5 U染色体各含有1对随体。分别以Oligo-pSc 119.2-1(绿色)与(GAA)7(红色)重复序列为探针对小伞山羊草根尖细胞染色体进行FISH分析,发现Oligo-pSc-119.2-1信号主要分布在染色体的端部及近端部,不同染色体之间的信号强度有所差别。(GAA)7信号主要集中于染色体着丝点附近,不但比Oligo-pSc-119.2-1信号的亮度高,分布丰富,而且在染色体上的分布可与Oligo-pSc-119.2-1信号互补。因此,同时采用Oligo-pSc-119.2-1与(GAA)72种探针能准确地辨别小伞山羊草的每对染色体,建立了小伞山羊草的FISH核型。     

粗山羊草(Aegilops squarrosa)的染色体和同工酶分析

利用火焰干燥涂片法制片和吉姆沙染液分化染色,分析了粗山羊草的染色体组型和 C-带带型。粗山羊草具有7对染色体,包括5对中部着丝点染色体、1对亚中部着丝点染色体和1对随体染色体。除第1对染色体外,所有染色体都具着丝点带。有的染色体具变化较大的中间带和末端带。据聚丙烯酰胺凝胶电泳分析粗山羊草的酯酶和过氧化物酶同工酶,在幼苗不同时期,其酶谱是不同的。     

提莫菲维小麦染色体的C-带分析

对提莫菲维小麦的根尖细胞染色体进行C-带分析,以明确提莫菲维小麦的染色体C-带带型特点。结果表明:提莫菲维小麦具有14对染色体,其染色体带型公式为:2 n=28=4 IT++4 IT++6 CIT++6 I+2 IT+2 CI+2 CIT+S+2 CIS,共包括98条带,其中长臂具有57条带纹,包括50条中间带(I),7条端带(T);短臂具有35条带纹,包括30条中间带(I),3条端带(T),2条随体带(S);另外还有着丝点带(C)6条。提莫菲维小麦G组染色体的异质化程度明显高于A组染色体,G组染色体的C-带带型与普通小麦B组染色体非常相似,因此G组染色体可能与B组染色体存在部分同源性。     

普通小麦贵紫麦1号染色体的FISH核型分析

采用FISH(荧光原位杂交)技术,分析普通小麦贵紫麦1号染色体的FISH核型特点,为贵紫麦1号在小麦新品种选育上的应用提供参考。结果表明,贵紫麦1号包括21对染色体,pAs 1红色探针信号主要分布在A组和D组染色体上,pSc 119.2-1绿色探针信号则主要分布在B组染色体上;根据贵紫麦1号染色体上这2种探针的分布特征,可以准确辨识每条染色体。贵紫麦1号与硬粒小麦(AABB)在2A、5A、2B、3B及5B染色体上表现出pSc 119.2-1信号分布差异,与节节麦(DD)在染色体1D、4D及5D上也存在信号分布差异,与中国春(AABBDD)在2A、5A、6B、1D及7D染色体上的信号也各有不同,说明DNA重复序列在不同小麦材料之间具有多态性。     

岷江百合根尖染色体的C-分带和FISH分析

利用Giemsa C-分带和荧光原位杂交(FISH)的方法对岷江百合(L.regale)根尖染色体进行了研究.结果表明岷江百合的带型公式为:2n=24=4I 8CL 2I 6I 2I T 2I T ,每条染色体都显示出了可以明显区别的特征带,带纹强弱差异明显.以45S rDNA为探针对岷江百合根尖染色体进行了荧光原位杂交,杂交点数为5对,分别位于A、B、H和K 4对同源染色体的着丝点区域和一对G染色体的长臂上.通过Giemsa C-带和HSH的方法可以将岷江百合的每条染色体区分开来.     

一粒小麦的染色体和同工酶分析

利用火焰干燥涂片法制备染色体玻片标本,观察到野生一粒小麦(T.boeo-ticum)和栽培一粒小麦(T.monococcum)的染色体组型基本相同。它们都具有着丝点带,但其中间带和末端带有些差别。在我们实验中它们的过氧化物同工酶及幼苗早期的酯酶同工酶酶谱也基本相似。因此野生一粒小麦和栽培一粒小麦可以归为一个一粒小麦种(T.monococcum),在小麦进化中,它们提供了 A 组染色体。     

顶芒山羊草特异寡核苷酸探针开发和oligo-FISH核型构建

栽培小麦近缘物种顶芒山羊草(Aegilops comosa, 2n=2x=14, MM)是小麦改良的三级基因库。为准确鉴定顶芒山羊草M基因组染色体或染色体区段,本研究利用二代测序获得顶芒山羊草M基因组序列信息,从中鉴定出16条可能的特异卫星重复序列。根据这些序列设计12个寡核苷酸(oligo)探针进行oligo-FISH,结果表明,其中10个探针可在顶芒山羊草染色体上产生明显的杂交信号。对探针特异性分析发现, 5个探针仅在顶芒山羊草染色体上产生杂交信号,在小麦染色体上未观察明显杂交信号,可作为顶芒山羊草特异探针鉴定小麦背景中的顶芒山羊草染色体。选择在顶芒山羊草染色体上信号分布丰富的3个探针(oligo-pAc89、oligo-pAc148、oligo-pAc225)组成探针套ONPS#AC1,结合利用本实验室根据小麦D亚基因组开发的寡核苷酸探针库,构建了顶芒山羊草的oligo-FISH核型。本研究构建的FISH核型可以准确识别顶芒山羊草各条染色体,为挖掘、转移和利用顶芒山羊草优异基因提供了快速准确的鉴定手段。     

杀配子染色体及其在创制小麦族染色体易位系中的应用

山羊草属植物中的某些染色体,当其单体附加到小麦基因组时,能使带有该染色体的配子正常存活;而使无该染色体的配子发生染色体断裂,产生易位等染色体结构畸变。利用杀配子染色体创制易位系是将小麦近缘种属野生资源的优良性状转移给小麦的一个有效途径。本文介绍了杀配子染色体的类型、作用时期,并重点综述了利用杀配子染色体创制小麦族染色体易位系方面的研究进展。     

普通小麦B染色体组起源的研究进展

很早就认识到多倍化在小麦的进化上有很大的作用。Kihara(1924)分析了不同倍性小麦的种间杂种,表明普通小麦是由ABD3个染色体组构成的异源多倍体。以后的研究证明A、D两染色体组分别由野生一粒小麦(T、aegilopoides)和塔斯其小麦(T、tauschii.Aeg、sgurrose)提供。关于B染色体组的起源,尽管进行过     

粗山羊草全基因组Aux/IAA基因家族的分离、染色体定位及序列分析

生长素是植物生长发育过程中的关键激素之一,Aux/IAA家族基因是重要的生长素原初响应基因。通过生物信息学方法从粗山羊草(Aegilops tauschii)全基因组中分离出28个Aux/IAA基因,其中20个粗山羊草Aux/IAA蛋白具有4个保守结构域;28个Aux/IAA基因分布于全部7对染色体上,5个基因分别具有位于同一位点的已知标记。粗山羊草IAA3、IAA11和IAA26的表达具有组织特异性,分别在雌蕊、种子和根中特异表达。系统发育显示,11对粗山羊草-乌拉尔图小麦Aux/IAA蛋白、5对粗山羊草-大麦Aux/IAA蛋白直系同源。共线性分析表明,粗山羊草Aux/IAA基因与短柄草、水稻中同源基因具有很好的共线性。本研究分离的相关基因不仅可用于小麦的遗传改良,也为深入研究小麦Aux/IAA基因提供了信息。     

Genetic analysis of the Aegilops longissima 3S chromosome carrying the Pm13 resistance gene

The distal region of the short arm of chromosome 3S from Aegilopslongissima, which carries the powdery mildew resistance gene Pm13, was introgressed into common wheat. Due to suppression of recombination between this region and corresponding wheat homoeologous segments, a possible strategy to construct a genetic map around the Pm13 gene was based on crosses between a wheat addition line carrying the Ae.longissima 3S chromosome and the corresponding 3S addition lines of Ae.searsii and Ae. variabilis. The efficiency of this strategy was evaluated by scoring recombination frequencies inprogenies derived from these crosses. Recombination between 3S chromosomes fromAe. searsii and Ae. longissimawas very low, whereas 26.5% recombinant alien chromosomes were obtained from the cross involving the Ae. variabilisand Ae. longissima 3S addition lines. These data were used to construct a3S chromosome map that resulted largely colinear to the consensus map of the homoeologous group 3 of wheat. This revised version was published online in July 2006 with corrections to the Cover Date.     

A microsatellite marker linked to leaf rust resistance transferred from Aegilops triuncialis into hexaploid wheat

Aegilops triuncialis (UUCC) is an excellent source of resistance to various wheat diseases, including leaf rust. Leaf rust‐resistant derivatives from a cross of a highly susceptible Triticum aestivum cv.‘WL711’ as the recurrent parent and Ae. triuncialis Ace.3549 as the donor and with and without a pair of acrocentric chromosomes were used for molecular tagging. The use of a set of sequence tagged microsatellite (STMS) markers already mapped to different wheat chromosomes unequivocally indicated that STMS marker gwm368 of chromosome 4BS was tightly linked to the Ae. triuncialis leaf rust resistance gene transferred to wheat. The presence of the Ae. Triuncialis‐specific STMS gwm368 homoeoallele along with the non‐polymorphic 4BS allele in the rust‐resistant derivatives with and without the acrocentric chromosome indicates that the resistance has been transferred from the acrocentric chromosome to either the A or the D genome of wheat. This alien leaf rust resistance gene has been temporarily named as LrTr.     

Chromosomal Assignment of Three Enzyme Coding Loci (Icd1, Nad-Mdh1 and Aco1) Using Primary Trisomics in Beet (Beta vulgaris L.)

Resistance to Septoria nodorum was investigated in seedlings of an amphiploid generated from Triticum dicoccum Shübl. and Aegilops squarrosa Tausch, and in a series of substitution lines of single chromosomes from this synthetic hexaploid into Triticum aestivum cv. ‘Chinese Spring’ in three tests to determine the chromosomal location of resistance. From the Ae. squarrosa parent (D genome), chromosome 5D was found to confer a high level of resistance, reducing lesion cover to near that of the amphiploid in the three tests. Chromosomes 3D, and to a lesser extent, 7D were also found to confer significant resistance to the amphiploid. Three chromosomes, 2A, 3B and 5A, from the T. dicoccum parent (AB genomes) also conferred resistance but to a lesser extent than 7D. Two chromosomes, 2B and 2D, caused a significant decrease in resistance. ‘Chinese Spring’ may thus carry genes for resistance to S. nodorum on these chromosomes which are absent in the synthetic hexaploid.     

Formation of unreduced gametes is impeded by homologous chromosome pairing in tetraploid <Emphasis Type="Italic">Triticum turgidum</Emphasis> × <Emphasis Type="Italic">Aegilops tauschii</Emphasis> hybrids

It is believed that unreduced gametes with somatic chromosome numbers play a predominant role in natural polyploidization. Allohexaploid bread wheat originated from spontaneous hybridization of Triticum turgidum L. with Aegilops tauschii Coss. Unreduced gametes originating via meiotic restitution, including first-division restitution (FDR) and single-division meiosis (SDM), are well documented in triploid F₁ hybrids of T. turgidum with diploid Ae. tauschii (genomic constitution ABD, usually with 21 univalents in meiotic metaphase I). In this study, two T. turgidum lines known to carry genes for meiotic restitution were crossed to tetraploid Ae. tauschii. The resulting F₁ hybrids (genomes ABDD), had seven pairs of homologous chromosomes and regularly formed 14 univalents and seven bivalents at metaphase I. Neither FDR nor SDM were observed. The distribution of chromosome numbers among progeny obtained by self pollination and a backcross to T. turgidum showed the absence of unreduced gametes. These results suggest that high homologous pairing interfered with meiotic restitution and the formation of unreduced gametes. This may be related to asynchronous movement during meiosis between paired and unpaired chromosomes or to uneven distribution of chromosomes in anaphases, resulting in nonviable gametes.     

杀配子染色体在小麦-黑麦异代换系中的作用研究

利用小麦-黑麦异代换系H-13(1R/1D), H-24(5R/5A),H-33(6R/6A)与中国春-杀配子染色体二体异附加系CS-DA2C(来自山羊草Ae. cylindrica),CS-DA3C(来自山羊草Ae. triuncialis)配置杂交组合,对杀配子染色体的作用进行了研究。结果表明,杀配子染色体3C对H-13和H-24都是致死的,即有着完全的杀配子作用,但对H-33的杀配子作用则是不完全的,有着接近正常的结实率,说明不同的小麦-黑麦异代换系遗传背景对杀配子作用有很大影响,可能在品系H-33中存在对2C染色体杀配子作用的抑制基因。在以品系H-33为母本时,2个杀配子附加系F1的自交结实率差异显著,说明在相同的小麦-黑麦异代换系遗传背景下,染色体2C与3C的杀配子作用是不同的,在这2个杀配子染色体上可能带有不同的杀配子基因?这些研究结果为进一步创制小麦-黑麦易位系奠定了基础。     

Transfer of rust resistance from Aegilops ovata into bread wheat (Triticum aestivum L.) and molecular characterisation of resistant derivatives

An interspecific cross was made to transfer leaf rust and stripe rust resistance from an accession of Aegilops ovata (UUMM) to susceptible Triticum aestivum (AABBDD) cv. WL711. The F₁was backcrossed to the recurrent wheat parent, and after two to three backcrosses and selfing, rust resistant progenies were selected. The C-banding study in a uniformly leaf rust and stripe rust resistant derivative showed a substitution of the 5M chromosome of Ae. ovata for 5D of wheat. Analysis of rust resistant derivatives with mapped wheat microsatellite makers confirmed the substitution of 5M for 5D. Some of these derivatives also possessed one or more of the three alien translocations involving 1BL, 2AL and 5BS wheat chromosomes which could not be detected through C-banding. A translocation involving 5DSof wheat and the substituted chromosome 5M of Ae. ovata was also observed in one of the derivatives. Susceptibility of this derivative to leaf rust showed that the leaf rust resistance gene(s) is/are located on short arm of 5M chromosome of Ae. ovata. Though the Ae. ovatasegment translocated to 1BL and 2AL did not seem to possess any rust resistance gene, the alien segment translocated to 5BS may also possess gene(s) for rust resistance. The study demonstrated the usefulness of microsatellite markers in characterisation of interspecific derivatives. This revised version was published online in August 2006 with corrections to the Cover Date.     

Tan-Spot Resistance Screening of Aegilops Species

Two hundred and twelve accessions of 8 diploid and 10 polyploid species of Aegilops were evaluated for resistance to tan-spot disease of wheat, caused by Pyrenophora tritici-repentis (Died.) Drechs., under greenhouse conditions. One or more accessions of Ae. bicornis, Ae. biuncialis, Ae. Crassa, Ae. columnaris, Ae. cylindrica, Ae. speltoides, Ae. squarrosa. Ae. triaristata. Ae. triuncialis, and Ae. Ovata showed resistance following a 24-hour post-inoculation wet period. With a 36-hour wet period, diploids became only slightly or moderately susceptible and resistant polyploids became susceptible. A 48-hour wet period resulted in still greater susceptibility of both diploid and polyploid species.     

Ph I-induced transfer of leaf and stripe rust-resistance genes from Aegilops triuncialis and Ae. geniculata to bread wheat

Leaf and stripe rusts are severe foliar diseases of bread wheat. Recently, chromosomes 5M^g from the related species Aegilops geniculata that confers resistance to both leaf and stripe rust and 5U^t from Ae. triuncialis conferring resistance to leaf rust have been transferred to bread wheat in the form of disomic DS5M^g(5D) and DS5U^t(5A) chromosome substitution lines. The objective of this study was to shorten the alien segments in these lines using Ph ^I-mediated, induced homoeologous recombination. Putativerecombinants were evaluated for their rust resistance, and by genomic in situ hybridization and microsatellite analyses. One agronomically useful wheat-Ae. geniculata recombinant resistant to leaf and stripe rust was identified that had only a small terminal segment of the 5M^gL arm transferred to the long arm of an unidentified wheat chromosome. This germplasm can be used directly in breeding programs. Only one leaf rust-resistant wheat-Ae. triuncialis recombinant, which consists of most of the complete 5U^t chromosome with a small terminal segment derived from 5AS, was identified. This germplasm will need further chromosome engineering before it can be used in wheat improvement. This revised version was published online in August 2006 with corrections to the Cover Date.