普通小麦–簇毛麦种质对菲利普孢囊线虫的抗性分析

菲利普孢囊线虫(Heterodera filipjevi)是在我国新发现的一种小麦病原线虫, 已严重威胁我国小麦的安全生产。小麦近缘种属具有改良小麦所需的许多目标性状, 是丰富小麦遗传变异、选育抗病品种的重要基因资源。采用室内接种鉴定法, 从20份小麦近缘属种材料中发现簇毛麦(Dasypyrum villosum)高抗H. filipjevi。分别对3套普通小麦–簇毛麦染色体附加系和6VS易位系进行接虫抗性鉴定, 结果6V染色体附加系高抗H. filipjevi;含6VS的易位系则表现感病。据此推测, 簇毛麦6V染色体上可能含有抗H. filipjevi基因, 且可能位于6VL上。     

农艺性状优良冬小麦ph1b系的创造及标记辅助选择的应用

利用改进的桥梁亲本法, 即以阿勃5B缺体为桥梁亲本, 分别与受体冬小麦推广品种(农大95、 京411和京冬8号)和中国春ph1b突变体杂交, 两个组合F1(即5BPh1和5Bph1b单体)再杂交, 后代选择5Bph1b单体与受体亲本5BPh1单体杂交, 仅3个世代就获得了3个冬小麦ph1b中间育种系, 在杂交转育过程中, 我们用先前获得的3个SCAR标记对5     

普通小麦(Taestivum)ph1b、ph2a、ph2b基因系与黑麦(Secale cereale)的杂交及回交研究

利用中国春ph1b、ph2a、ph2b基因系及对照中国春分别与甘肃黑麦杂交,结实率分别为94.0％、87.9％、93.8％和90.8％,其F_1减数分裂中期Ⅰ染色体配对交叉数分别为9.748、2.968、5.000和1.376,ph1b、ph2a、ph2b基因诱导小麦与黑麦F_1部分同源染色体配对顺序是ph1b>ph2b>ph2a。用中国春回交F_1取得了成功,回交结实率分别为1.06％     

Production and cytogenetics of intergeneric hybrids between Triticum durum-Dasypyrum villosum amphidiploid and Psathyrostachys huashanica

Summary Intergeneric crosses between Triticum durum-Dasypyrum villosum (2n=42, AABBVV), and Psathyrostachys huashanica (2n=14, N ^h N ^h ) were made, the seed set was 1.67%. Intergeneric hybrid were successfully obtained by means of embryo culture for first time. The average chromosome pairing in the hybrid (ABVN ^h ) was 26.61% univalents, and 0.69 bivalents. The chiasmata per cell was 0.69. The chiasmata was higher than that in Triticum durum dihaploid (AB), and lower than that in T. durum-Dasypyrum villosum trihaploid (ABV). The result indicated that the N ^h genome of Psathyrostachys huashanica has no homology with the V genome of Dasypyrum villosum, and the A and B genomes of Triticum durum. The coenocytism, micronuclei cell and variation in chromosome numbers were also observed. The F₁ hybrid was crossed with Triticum aestivum (AABBDD), and resulted in seed set. The hybrid of T. durum-D. villosum amphidiploid x P. huashanica showed partial fertility. It made the possibility for chromosome manipulation among Triticum aestivum, Dasypyrum villosum and Psathyrostachys huashanica.     

Nearly Total Absence of Homoeologous Pairing in a Hybrid between Tetraploid Hordeum chilense and Triticum aestivum

A hybrid between an induced tetraploid of Hordeum chilense (2n = 28 = H^chH^chH^chH^ch) and Triticum aestivum var. ‘Chinese Spring’ (2n = 42 = AABBDD) has been produced to test gene effects of this wild barley on homoeologous pairing in wheat. Cytological investigations in metaphase I have shown that the hybrid, which is perennial like H. chilense but morphologically more similar to the wheat parent, possesses the expected genome composition H^chH^ch ABD and a stable euploid chromosome number of 2n = 35. Pairing among the homologous H. chilense chromosomes was almost complete. The level of non-homologous chromosome association proved to be lower than the range of pairing known from euhaploids of ‘Chinese Spring’.     

The 1BL/1RS chromosome translocation effect on yield characteristics in a Triticum aestivum L. cross

Comparisons involving 28 random F₂-derived F₆ wheat (Triticum aestivum L.) lines from the cross, ‘Nacozari’/‘Seri 82’, suggested that advanced derivatives with the 1BL/1RS chromosome translocation possess superior agronomic performance in both full and reduced irrigation conditions when compared with 1B derivatives. This performance advantage was attributed to high grain yield, above-ground biomass at maturity, grains/spike, 1000-grain weight and test weight. The 1BL/1RS lines were shorter with delayed flowering and maturity. The superiority of the 1BL/1RS translocation group on grains/m² was expressed only under the full irrigation environment. Higher harvest index, longer spike-length and grain-filling period were detected only under reduced irrigation conditions. A significant grain yield relationship with test weight was detected only among the 1BL/1RS genotypes, indicating that they possess heavier and plumper grains than the 1B genotypes.     

The Effect of Chromosome 1B/1R Translocation on the Yield Potential of Certain Spring Wheats (Triticum aestivum L.)

Nearly 50 percent of the 1988 advanced breeding lines of the CIMMYT bread wheat breeding program possess the 1B/1R homozygous translocation. Hence, a trial was conducted to estimate the effect of 1B/1R chromosome translocation on the yield potential of some of our high-yielding spring wheats, where non-limiting levels of fertility, moisture, preventive pest and disease programs were used. In conclusing the 1B/1R lines seemed to have increased their above-ground biomass yield, number of spikes per meter², 1000-grain weight and test weight. They also exhibited a slight advantage over the 1B homozygous lines on grain yield. The observed difference, however, was non-significant, as was the plant height difference observed among the two groups. Varietal comparisons indicated that the 1B/1R group headed later than the 1B group.     

Chromosome pairing in durum wheat haploids with and without <Emphasis Type="Italic">ph1b</Emphasis> of bread wheat

Durum or macaroni wheat (Triticum turgidum L., 2n = 4x = 28; AABB) is an allotetraploid with two related genomes, AA and BB, each with seven pairs of homologous chromosomes. Although the corresponding chromosomes of the two genomes are potentially capable of pairing with one another, the Ph1 (Pairing homoeologous) gene in the long arm of chromosome 5B permits pairing only between homologous partners. As a result of this Ph1-exercised disciplinary control, durum wheat and its successor, bread wheat (Triticum aestivum L., 2n = 6x = 42; AABBDD) show diploid-like chromosome pairing and hence disomic inheritance. The Ph mutants in the form of deletions are available in bread wheat (ph1b) and durum wheat (ph1c). Thus, ph1b-haploids of bread wheat and ph1c-haploids of durum wheat show extensive homoeologous pairing that has been shown by us and several others. Here we study the effect of ph1b allele of bread wheat on chromosome pairing in durum haploids, whereas we studied earlier the effect of ph1c allele in durum haploids that we synthesized. In durum wheat, the ph1b-haploids show much higher (49.4% of complement) pairing than the ph1c-haploids (38.6% of complement). Mention of a trademark or proprietary product does not constitute a guarantee or warranty of the product by the USDA or imply approval to the exclusion of other products that also may be suitable.     

Mapping of the Vrn-B1 gene in Triticum aestivum using microsatellite markers

An F₂ population segregating for the dominant gene Vrn‐B1 was developed from the cross of the substitution line ‘Diamant/'Miro‐novskaya 808 5A’ and the winter wheat cultivar ‘Bezostaya 1′. Microsatellite markers (Xgwm and Xbarc) with known map locations on chromosome 5B of common wheat were used for mapping the gene Vrn‐B1. Polymorphism between parental varieties was observed for 28 out of 34 microsatellite markers (82%). Applying the quantitative trait loci mapping approach, the target gene was mapped on the long arm of chromosome 5B, closely linked to Xgwm408. The map position of Vrn‐B1 suggests that the gene is homoeologous to other vernalization response genes located on the homoeologous group 5 chromosomes of wheat, rye and barley.     

A New Intergeneric Hybrid between Triticum aestivum L. and Agropyron fragile (Roth) Candargy: Variation in A. fragile for Suppression of the Wheat Ph-Locus Activity

New intergeneric hybrids were obtained between Triticum aestivum L. cv. Tukuho’ (2n = 6x = 42, AABBDD) and Agropyron fragile (Roth) Candargy PGR 8097 (2n = 4x = 28, PPPP) at a frequency of 1.06 %, through the use of direct embryo culture and in ovulo embryo culture. Such hybrids could be used to transfer barley yellow dwarf virus (BYDV) resistance and winterhardiness into bread wheat. The somatic chromosome number in all the hybrid plants was 2n = 5x = 35, as expected. Considerable variation in chromosome pairing was observed among the different hybrid plants. Average meiotic chromosome configuration at metaphase I was 17.29 Is + 6.57 rod Us + 1.97 ring Us + 0.18 III + 0.03 IV + 0.002 VI. The high level of chromosome pairing in some F₁ hybrids was attributed to Ph-suppressor gene(s) present in A. fragile. The hybrids could not be backcrossed to wheat, but amphiploid seeds have been obtained by colchicine treatment.     

Effect of Mutagenic Treatments on Somaclonal Variation in Wheat (Triticum aestivum L.)

Different wheat genotypes were treated with gamma-rays, sodium azide (SA) and EMS before tissue culture and immature embryos from M₁ plants or plants shortly after exposure to gamma-rays were used to initiate callus culture. Thousands of plants were regenerated and used to investigate the effect of mutagenic treatments on the regenerated plants and somaclonal variation in the M₃R₂ and M₂R₂ generations. The results showed that mutagen-induced damage in terms of reduction in plant height, fertility and spike length were not outstanding in the regenerated plants as compared with the untreated control. In the M₃R₂ generation, only SA treatment had significantly higher frequencies of somaclonal variations than the control. Increases in the variation frequencies were observed when explant embryos were irradiated with 2.5 and 5 gy gamma-rays and the highest frequency appeared when embryos were exposed to 5 gy gamma-rays on the 5th day after anthesis. Increased variation spectra also resulted from mutagenic treatments and most of the variants recovered were unsuitable for plant improvement.     

Relationship between hybrid performance and genetic diversity based on RAPD markers in wheat, Triticum aestivum L.

Random amplified polymorphic DNA (RAPD) markers were generated from 20 wheat, Triticum aestivum lines. Fifty-four fragments generated by six primers of a 10-mer arbitrary sequence were used to study their potential power in differentiating parents with different characteristics and predicting the yield performance of hybrids produced from these parents. Experimental results showed that the 20 wheat lines were divided into four groups. Group I was characterized by more grains per spike, group II by heavy grains and group III by more spikes per unit area and short plants; group IV was similar to group III but had a much higher biomass yield and grain yield. Hybrids from parents in different groups were generally superior to most hybrids from parents in the same group. Both yield performance and heterosis of hybrids from parents between group I and group III were much better than those of other intergroup hybrids. These results suggest that, based on RAPD markers, it is possible to differentiate wheat lines with different performances and that the classification of parents from these markers is of predictive value for developing superior hybrids. However, genetic distance (GD) based on RAPD markers was not significantly correlated with hybrid performance and heterosis. It appears to be impossible to predict hybrid performance from GD itself.     

簇毛麦6VS特异转录序列P21461及P33259的获得及其分子标记在鉴定小麦-簇毛麦抗白粉病育种材料中的应用

簇毛麦6V#2S和6V#4S染色体臂分别携带抗白粉病基因Pm21和Pm V,在与小麦的杂种后代中,抗病基因与外源染色体臂共分离。开发鉴定2条外源染色体臂间多态性的序列,尤其是遗传信息相对缺乏的6V#4S染色体臂的序列,对于其在遗传与育种上的应用具有重要意义。本研究以携带6V#4S·6DL染色体的小麦易位系Pm97033及感病小麦亲本宛7107接种白粉菌的叶片转录组数据为资源,通过差异基因筛选、共线性分析、簇毛麦基因组扩增及测序验证的方法,鉴定出来自6V#4S的表达序列P21461和P33259,其中基于P21461序列设计的引物P461-5在簇毛麦6V#2S和6V#4S染色体臂的扩增产物具有30 bp的In Del和4 nt的多态性。用该引物转化的标记P461-5a可以鉴定抗白粉病小麦品种和高代品系所含的外源染色体,显示其在簇毛麦抗源鉴别和小麦抗病育种辅助选择中潜在的应用价值。根据P33259开发的标记P259-1可以对含有6V#4S染色体臂的材料进行特异扩增,但对6V#2S·6AL易位染色体没有扩增产物,因此P259-1可作为6V#4S·6DL易位染色体的特异分子标记。q RT-PCR分析结果显示,P21461的表达不受白粉菌诱导,而P33259在接菌后12 h和24 h的转录水平比接菌前提高约2倍,推测其可能参与Pm97033与白粉菌的早期互作。     

小麦供锌状况对叶片结构及叶绿体超微结构的影响

锌缺乏或过量使小麦叶肉细胞变小,多环复式细胞显著减少。缺锌植株的叶绿体中基粒垛数少,基粒垛叠片层少,基质片层少,部分片层膨胀;叶绿体内包含较大的液泡和淀粉“泡”;叶绿体被膜模糊,甚至消失.锌过量则使小麦的叶绿体变小,基粒和基质片层明显减少,部分片层膨胀,亲锇颗粒多;在叶绿体周围线粒体出现较多.     

Effect of Toxic Metals on the Multiple Forms of Esterases of Triticum aestivum cv. Vergina

The influence of increasing concentrations of copper, zinc, lead, nickel, chromium and cadmium on 14 day-old seedlings of Triticum aestivum cv. Vergina was studied. Plants were grown in 1/10 strength Rorison's nutrient solution plus increasing concentrations of each one of the toxic metals separately. Metal toxicity depressed shoot growth but the most evident symptoms were on roots.
The effects of toxic metals on the isoesterases of Triticum aestivum cv. Vergina shoots were classified into three types, depending on the increase or decrease of the number and density of esterase bands compared to the control:
1. Decreased number and density of bands caused by 20 ppm Cd, 8 ppm Ni and 60 ppm Zn.
2. Constant number of bands but decreased intensities caused by 2 ppm Cu and 40 ppm Pb.
3. Constant number of bands but increased intensities caused by 20 ppm Cr.
These effects demonstrate the diverse modes of metal action resulting in different degrees of toxicity.     

Glu-D1位点亚基缺失弱筋小麦新种质的创制及其品质分析

辐射诱变是一种重要的变异手段,为了丰富小麦的品质性状变异资源,通过采用60Co-?射线辐射普通小麦品种‘冀3235’幼胚愈伤组织的方法,获得辐射诱变处理的再生植株。对再生株后代种子进行麦谷蛋白亚基的SDS-PAGE分析,结果从中发现了不含Glu-D1位点编码的高分子量麦谷蛋白亚基的材料。经进一步的系谱选择,选育成了稳定遗传的7份材料。与对照‘冀3235’相比,这些株系的农艺性状无明显差异,醇溶蛋白A-PAGE电泳谱带也完全相同,仅在麦谷蛋白SDS-PAGE电泳图谱的Glu-D1位点上有差异（变异系缺少Glu-D1位点控制的亚基,对照‘冀3235’为2+12）。品质分析结果表明,Glu-D1位点缺失系的面粉品质发生了很大变化,其湿面筋没有检出,沉降值显著下降。这些变异系是培育弱筋小麦品种和评价Glu-D1位点功能的珍贵材料。     

Generation and characterization of a high molecular weight glutenin 1Bx14-deficient mutant in common wheat

Significant progress has been made in understanding the structure of high molecular weight (HMW) glutenin subunits and their role in determining the end use quality of wheat grains. However, few reports have dealt with the development and characterization of knock out mutants for HMW glutenin subunit genes. Here, the molecular analysis of MB14, a mutant derived from an elite Chinese wheat variety Xiaoyan 54 through chemical mutagenesis is described. SDS‐PAGE and Western blot experiments revealed that, in the seeds of homozygous MB14 plants, the expression of the 1Bx14 subunit was specifically blocked whereas the remaining four subunits (1Ax1, 1By15, 1Dx2, 1Dy12) accumulated to levels comparable to those in the wild type plants. The 5′‐flanking region and the open reading frame (ORF) of the mutant 1Bx14 allele were amplified and compared to the corresponding regions of wild type 1Bx14. The nucleotide sequences of the 5′‐flanking regions from the mutant and wild type 1Bx14 alleles were identical. However, the ORF of the mutant allele differed from that of the wild type 1Bx14 by three point substitutions, one of which resulted in a premature stop codon in the mutant ORF. Interestingly, the mutant 1Bx14 allele was still transcribed in the developing seeds, but no truncated translation product could be detected by Western blot analysis. Potential application of the 1Bx14 knock out mutant in studying the biological function of 1Bx14 and its contribution to the end use quality control in hexaploid wheat is discussed.     

八倍体小偃麦与普通小麦杂种自交和回交后代染色体和性状分离的研究

以八倍体小偃麦小偃６９３和普通小麦烟农１５的六个不同杂种世代为材料，研究了自交和顺交对杂种后代染色体和性状分离的不同影响。结果表明，随自交和以烟农１５为轮回亲本回交世代的增加，染色体数目逐渐减少，但回交比自交能使后代中偃麦草染色体丢失更快；回交后代ＰＭＣＭＩ染色体构型较为简单，平均交叉结数减少，回交次数过多不利于偃麦草与普通小麦染色体发生遗传重组；自交和回交世代中小偃麦类型、中间类型和小麦类型出现     

Genetical and anatomical analyses of a leaf flecking mutant in Triticum aestivum L.

Flecking trait in the mutant C591 (M8) Triticum aestivum L. is a stable,developmentally programmed, dominant mutation under monogenic control resembling pathogenic attack and starts appearing only from boot leaf stage of the plant. Mutant plants differ significantly from normal plants in terms of total chlorphyll contents only at later stages of symptom spread when the flecks fully cover the leaf sheath and leaves. However, total grain weight per main spike of mutant did not differ significantly from the normal plants. Microscopic studies of the mutant leaves did not reveal any damaging effect of the mutation on leaf anatomy per se, even though differences were observed in chlorophyll filling in mesophyll cells. Considering the peculiar characteristics of the mutation, many of which resembling the disease lesion mimic mutations in other crops, this is suspected to be such a mutation in wheat. This revised version was published online in August 2006 with corrections to the Cover Date.     

普通小麦颖壳蜡质缺失突变体glossy1的转录组分析

为了明确突变体颖壳蜡质含量显著变化的分子机制,本研究对源自济麦22颖壳蜡质缺失突变体glossy1与野生型进行了转录组分析。结果表明,在glossy1突变体中,共筛选到12,230个差异表达基因,其中5811个基因在突变体中上调表达,6419个下调表达。GO(gene ontology)功能富集分析发现,差异基因主要富集在蜡质合成和转运途径,具体分布在酰基转移酶活性、脂质结合和水解酶活性等条目,由此推测这些途径与小麦穗部蜡质缺失性状是紧密相关的。我们还利用RT-qPCR检测了参与蜡质代谢途径部分基因的表达,结果与转录组结果是一致的。本研究为今后探究小麦蜡质代谢的分子机制和基因调控网络提供了数据支持,同时也为抗逆小麦育种奠定了理论基础。