Resistance to fungal diseases in hybrid progeny from crosses between common wheat variety Saratovskaia 29 and the amphidiploid Triticum timopheevii/Triticum tauschii (AAGGDD)

The progeny of BC6F2-BC9F(2)-4 has been analyzed for resistance to brown rust (Lr genes) and powdery mildew (Pm genes). This progeny was obtained due to introgression of the alien material from the synthetic hexaploid wheat Triticum timopheevii/Aegilops squarrosa (= Triticum tauschii AAGGDD, 2n = 42) into the common wheat variety Saratovskaya 29. Against the background of natural infection, the lines resistant to both diseases and to either of them were developed. The brown-rust and powdery-mildew resistance is controlled by one/two effective independent genes Lr and Pm.     

Construction of Immune Lines with Complex Resistance to Leaf Rust and Powdery Mildew in Common Spring Wheat Cultivar Saratovskaya 29

Immune lines resistant both to leaf rust and to powdery mildew were constructed on the basis of common wheat cultivar Saratovskaya 29. Synthetic wheat Triticum timopheevii/Aegilops squarrosa (AAGGDD, 2n = 42) of Savov (Bulgaria) was used as a source of resistance genes. Using cytological analysis of BC₂, we selected resistant plants (21") free from meiosis 1 (M1) defects. With these plants and continuous selection, BC₈–BC₉ immune lines were obtained. The lines were shown to carry new resistance genes differing from the known ones, and were proposed as donors of immunity to the diseases.     

甘蔗与斑茅割手密复合体杂交后代的分子标记鉴定

为有效利用甘蔗野生种质拓宽甘蔗遗传基础,本研究利用甘蔗与斑茅割手密复合体进行杂交,同时应用序列相关扩增多态性(SRAP)和微卫星(SSR)分子标记技术鉴定其后代。两种分子标记鉴定结果相互印证表明:3个杂交组合的后代中,经表型鉴定含斑茅血缘的34个后代为真杂种。该真杂种后代为进一步综合利用斑茅、割手密的优异基因改良甘蔗品种提供了优良的创新种质。     

Accelerated Senescence and Enhanced Disease Resistance in Hybrid Chlorosis Lines Derived from Interspecific Crosses between Tetraploid Wheat and Aegilops tauschii

Hybrid chlorosis, a type of hybrid incompatibility, has frequently been reported in inter- and intraspecific crosses of allopolyploid wheat. In a previous study, we reported some types of growth abnormalities such as hybrid necrosis and observed hybrid chlorosis with mild or severe abnormalities in wheat triploids obtained in crosses between tetraploid wheat cultivar Langdon and four Ae. tauschii accessions and in their derived synthetic hexaploids. However, the molecular mechanisms underlying hybrid chlorosis are not well understood. Here, we compared cytology and gene expression in leaves to characterize the abnormal growth in wheat synthetics showing mild and severe chlorosis. In addition, we compared disease resistance to wheat blast fungus. In total 55 and 105 genes related to carbohydrate metabolism and 53 and 89 genes for defense responses were markedly up-regulated in the mild and severe chlorosis lines, respectively. Abnormal chloroplasts formed in the mesophyll cells before the leaves yellowed in the hybrid chlorosis lines. The plants with mild chlorosis showed increased resistance to wheat blast and powdery mildew fungi, although significant differences only in two, third internode length and maturation time, out of the examined agricultural traits were found between the wild type and plants showing mild chlorosis. These observations suggest that senescence might be accelerated in hybrid chlorosis lines of wheat synthetics. Moreover, in wheat synthetics showing mild chlorosis, the negative effects on biomass can be minimized, and they may show substantial fitness under pathogen-polluted conditions.     

一个来自硬粒小麦的抗白粉病基因的鉴定和微卫星标记

在起源于硬粒小麦(Triticum durum Desf.accession DR147)和尾状山羊草(Aegilops caudata L.acc.Ae14)合成的双二倍体与普通小麦品种"莱州953"杂交组合衍生的BC3F2群体中鉴定了一个抗小麦白粉病基因.遗传分析表明,该基因为一个显性单基因.应用分离群体分组法(BSA),鉴定了两个与抗病基因紧密连锁的微卫星标记Xgwm311和Xgwm382,它们与抗病基因的遗传距离分别为5.9 cM和4.9 cM.对双二倍体亲本硬粒小麦DR147和尾状山羊草Ae14及轮回亲本"莱州953"的DNA PCR扩增结果表明,与抗病基因相关的微卫星标记Xgwm311和Xgwm382来源于硬粒小麦DR147.根据已发表的小麦微卫星图谱和对"中国春"缺-四体系DNA扩增结果,抗病基因被定位在小麦2A染色体的长臂末端.     

一个来自硬粒小麦的抗白粉病基因的鉴定和微卫星标记

在起源于硬粒小麦(TriticumdurumDesf.accessionDR147)和尾状山羊草(AegilopscaudataL.acc.Ae14)合成的双二倍体与普通小麦品种“莱州953”杂交组合衍生的BC3F2群体中鉴定了一个抗小麦白粉病基因。遗传分析表明,该基因为一个显性单基因。应用分离群体分组法(BSA),鉴定了两个与抗病基因紧密连锁的微卫星标记Xgwm311和Xgwm382,它们与抗病基因的遗传距离分别为5.9cM和4.9cM。对双二倍体亲本硬粒小麦DR147和尾状山羊草Ae14及轮回亲本“莱州953”的DNAPCR扩增结果表明,与抗病基因相关的微卫星标记Xgwm311和Xgwm382来源于硬粒小麦DR147。根据已发表的小麦微卫星图谱和对“中国春”缺-四体系DNA扩增结果,抗病基因被定位在小麦2A染色体的长臂末端。     

The Characteristics of Primary Hybrids Obtained in Crosses between Common Wheat from China and Cultivated Rye

Russian Journal of Genetics - The gene pool of winter common wheat from China maintained in the VIR collection is unique in the variety of alleles of the genes of selection-valuable traits and...     

小麦品种Triticum spelta album中抗条锈病基因Yr5的RAPD标记

共用520个10碱基随机引物对小麦抗条锈基因Yr5的近等基因系进行了RAPD分析,发现了3个特异性DNA片段S1496、S14181950与Yr5基因连锁,其中S1496761与Yr5基因紧密连锁,遗传距离为2．7cM。经对特异性DNA片段S1496 761进行克隆,测序,设计了PCR扩增用专化引物SC－S1496 761a和SC－S149676b,用该引物可扩增出与原RAPD引物扩增出的相似的特异DNA片段,由于该引物还可扩增出迁移率极为相近的另1条非特异带,在琼脂糖凝胶上难以分辨,需用聚丙烯酰胺凝胶电泳结合银染进行检测,经用F2分离群体及部分相关品种材料检测,已证明该标记的可靠性。     

Resistance to wheat leaf rust and stem rust in Triticum tauschii and inheritance in hexaploid wheat of resistance transferred from T. tauschii.

Twelve accessions of Triticum tauschii (Coss.) Schmal. were genetically analyzed for resistance to leaf rust (Puccinia recondita Rob. ex Desm.) and stem rust (Puccinia graminis Pers. f.sp. tritici Eriks. and E. Henn.) of common wheat (Triticum aestivum L.). Four genes conferring seedling resistance to leaf rust, one gene conferring seedling resistance to stem rust, and one gene conferring adult-plant resistance to stem rust were identified. These genes were genetically distinct from genes previously transferred to common wheat from T. tauschii and conferred resistance to a broad spectrum of pathogen races. Two of the four seedling leaf rust resistance genes were not expressed in synthetic hexaploids, produced by combining tetraploid wheat with the resistant T. tauschii accessions, probably owing to the action of one or more intergenomic suppressor loci on the A or B genome. The other two seedling leaf rust resistance genes were expressed at the hexaploid level as effectively as in the source diploids. One gene was mapped to the short arm of chromosome 2D more than 50 cM from the centromere and the other was mapped to chromosome 5D. Suppression of seedling resistance to leaf rust in synthetic hexaploids derived from three accessions of T. tauschii allowed the detection of three different genes conferring adult-plant resistance to a broad spectrum of leaf rust races. The gene for seedling resistance to stem rust was mapped to chromosome ID. The degree of expression of this gene at the hexaploid level was dependent on the genetic background in which it occurred and on environmental conditions. The expression of the adult-plant gene for resistance to stem rust was slightly diminished in hexaploids. The production of synthetic hexaploids was determined to be the most efficient and flexible method for transferring genes from T. tauschii to T. aestivum, but crossing success was determined by the genotypes of both parents. Although more laborious, the direct introgression method of crossing hexaploid wheat with T. tauschii has the advantages of enabling selection for maximum expression of resistance in the background hexaploid genotype and gene transfer into an agronomically superior cultivar.     

冬小麦植物铁载体分泌的杂种效应

缺铁是石灰性土壤常见的植物营养问题之一。禾本科植物种或基因型的植物铁载体分泌能力与耐缺铁有关 ,提高植物铁载体分泌能力是改良缺铁的土壤上植物铁营养的关键措施之一。在水培条件下分析了冬小麦(TriticumaestivumL .) 3个杂交种及其 4个亲本在缺铁营养液中植物铁载体的分泌及杂种的效应。植物铁载体的分泌率通过根分泌物对新形成的Fe(OH) 3 的活化能力进行测定 ,在缺铁症出现时每隔 2、3天测定 1次。在缺铁条件下 ,所有基因型都分泌较多的植物铁载体 ,并且随缺铁症状的发展分泌量增加。杂交种具有对缺铁更敏感的反馈系统 ,在缺铁条件下 ,杂交种比亲本分泌铁载体的速度更快、量更高。通过分析杂交种和亲本的关系 ,认为可以通过对亲本分泌植物铁载体能力和配合力的选择 ,利用杂种优势来提高小麦铁的利用效率。     

冬小麦植物铁载体分泌的杂种效应

缺铁是石灰性土壤常见的植物营养问题之一.禾本科植物种或基因型的植物铁载体分泌能力与耐缺铁有关,提高植物铁载体分泌能力是改良缺铁的土壤上植物铁aestivum L.) 3个杂交种及其4个亲本在缺铁营养液中植物铁载体的分泌及杂种的效应.植物铁载体的分泌率通过根分泌物对新形成的Fe(OH)3的活化能力进行测定, 在缺铁症出现时每隔2、3天测定1次.在缺铁条件下,所有基因型都分泌较多的植物铁载体,并且随缺铁症状的发展分泌量增加.杂交种具有对缺铁更敏感的反馈系统,在缺铁条件下,杂交种比亲本分泌铁载体的速度更快、量更高.通过分析杂交种和亲本的关系,认为可以通过对亲本分泌植物铁载体能力和配合力的选择,利用杂种优势来提高小麦铁的利用效率.     

Molecular Cloning and Expression Analysis of the Starch-branching Enzyme III Gene from Common Wheat (Triticum aestivum )

The starch-branching enzyme (SBE) catalyzes the formation of branch points by cleaving the α-1,4 linkage in polyglucans and reattaching the chain via an α-1,6 linkage. Three types of SBE isoforms (SBEI, SBEII, and SBEIII) exist in higher plants, with the number of SBE isoforms being species-specific. This study isolated the SBEIII cDNA sequence (3,780 bp), designated TaSBEIII (accession no. JQ346193), from common wheat (Triticum aestivum L.) using the RACE method, revealing that the SBEIII gene exists in common wheat. The open reading frame of TaSBEIII was 2,748 bp. The predicted protein of 916 amino acids contained the specific characteristics of the SBEIII protein: four highly conserved regions and a central (α/β)₈ barrel domain. The SBE activity of the protein expressed in Escherichia coli (BL21) was also measured and verified. During the wheat grain filling period, TaSBEIII was constitutively expressed. The role of the TaSBEIII gene in starch synthesis is discussed.     

Resistance to Meloidogyne spp. in Allohexaploid Wheat Derived from Triticum turgidum and Aegilops squarrosa

Expression of resistance to Meloidogyne incognita and M. javanica from Aegilops squarrosa was studied in a synthetic allohexaploid produced from Triticum turgidum var. durum cv. Produra and Ae. squarrosa G 3489. The reproductive rate of different races of M. incognita and M. javanica, expressed in eggs per gram of fresh root, was low (P < 0.05) on the synthetic allohexaploid and the resistant parent, Ae. squarrosa G 3489, compared with different bread and durum wheat cultivars. Reproduction of race 2 and race 3 of M. incognita and an isolate of M. javanica was studied on the synthetic allohexaploid and seven cultivars of T. aestivum: Anza, Coker 747, Coker 68-15, Delta Queen, Double Crop, McNair 1813, and Southern Bell. The latter six cultivars are grown in the southeastern United States and reportedly were resistant to M. incognita. Significant differences (P < 0.05) were detected in nematode reproduction on the seven bread wheat cultivars. Reproduction of M. incognita race 3 and M. javanica was highest on Anza. Reproductive rates on the six southeastern United States bread wheat cultivars varied both within and among nematode isolates. The lowest reproductive rates of the three root-knot isolates were detected in the synthetic allohexaploid.     

Sources of Resistance to Common Bunt (Tilletia foetida and T. caries) in Durum Wheat

Screening of durum wheat germplasm for resistance to common bunt (Tilletia foetida and T. caries) resulted in the identification of 26 resistant genotypes. The screening was made using nine common bunt isolates from the West Asia and North Africa (WANA) region. In one isolate the two pathogens were represented in ratio of 1:1, whereas eight isolates contained only T. foetida. The correlation, principal components and clustering analyses grouped the genotypes into three clusters., Cluster one comparised genotypes close to Senatore (S.) Cappelli and Haurani, the latter is a landrace from Syria. Cluster three comprised advanced genotypes containing resistance genes from Mindum, a Turkish landrace. Results indicated that donor sources of resistance appear to be related to the three major sources mentioned. Cultivar S. Cappelli is considered resistant since it has been grown by farmers on a large scale for many years and remained resistant to common bunt throughout 7 years of testing. This resistance is assumed to be of a durable type. The isolates were also grouped into three clusters representing different ecological areas and the wheat types from which the isolates originated. We infer that the different clusters reflect the presence of three pathotype groups of the pathogens.     

A fertile amphiploid between durum wheat (Triticum turgidum) and the x Agroticum amphiploid (Agropyron cristatum x T. tauschii)

Agropyron (Gaertn) is a genus of Triticeae which includes the crested wheatgrass complex, i.e. A. cristatum (L.) as representative species containing the P genome. This species is an important source for increase the genetic variability of both durum and bread wheat. Among the possible interesting features to be introgressed into wheat are resistance to wheat streak mosaic virus, rust diseases, and tolerance to drought, cold and moderate salinity. By crossing tetraploid wheat (Triticum turgidum conv durum, 2n = 4x = 28; AABB) with a fertile allotetraploid (2n = 4x = 28; DDPP) between diploid wheat (T. tauschii) and crested wheatgrass (A. cristatum L.), amphiploid plants were obtained. Fluorescence in situ hybridization (FISH) using both genomic DNA from A. cristatum and the repetitive probe pAs1, proved that the plants were true amphiploids with a chromosome number 2n = 8x = 56 and genomic constitution AABBDDPP. Using total genomic in situ hybridization (GISH) to study meiotic metaphase I, data on allosyndetic and autosyndetic chromosome pairing were obtained. The amphiploids were perennial like the male parent but their morphology was close to that of the wheat parent. They were resistant to wheat leaf rust and powdery mildew under field conditions.     

外源1Dx5基因导致小麦高分子量麦谷蛋白亚基表达变异

目的:为了结合基因枪转化和传统杂交方法培育优质小麦品种,对转基因小麦和国内主栽小麦品种杂交后代外源基因遗传表达行为进行了研究。方法:采用SDS-PAGE对2个小麦杂交组合川89-107×B72-8-11b和鄂麦18×B72-8-11b的杂交及回交后代籽粒进行高分子量麦谷蛋白亚基遗传表达分析。结果:在亲本中能够稳定超量表达的外源基因1Dx5在杂交后代中出现了不同的表达量,而且在外源基因的影响下,杂交后代出现了新的、杂交亲本并不表达的高分子量麦谷蛋白亚基。结论:多拷贝的外源基因在不同于受体环境的细胞质中的表达发生了变化,且由于外源基因的插入引起了内源高分子量麦谷蛋白亚基组成的变异。     

中国春小麦puroindoline a基因的克隆及其真核表达载体的构建

目的:puroindoline(pin)基因在控制麦类作物的籽粒硬度中起着重要作用。构建真核表达载体pcDNA3.1( )-pina-gfp,为pina基因在哺乳细胞中的表达提供基础。方法:利用PCR方法从中国春小麦基因组中克隆到了pina基因,将其插入真核表达载体pcDNA3.1( )-gfp,用PCR和酶切鉴定重组子。结果:PCR和酶切鉴定表明,所构建的真核表达重组质粒为pcDNA3.1( )-pina-gfp;将该片段克隆到pCF-T载体中,经测序验证,表明其为目的基因。结论:构建的pina基因真核表达载体pcDNA3.1( )-pina-gfp为pina基因在哺乳动物细胞中的表达提供了基础。