基于SSR标记的粗山羊草遗传多样性分析

粗山羊草(Aegliops tauschii)是普通小麦遗传改良的重要基因资源.随机选取8份粗山羊草对普通小麦的211对SSR引物进行了引物筛选.选取稳定清晰、有特异带的32对SSR引物对78份粗山羊草进行多样性分析,共扩增出308个等位位点,平均每对SSR引物扩增出8.14个等位位点,其中A组引物、B组引物和D组引物分别扩增出39个、51个和212个等位位点,平均每个组等位位点分别为5.57个、6.38个和12.47个,D组引物检测到遗传变异最丰富,说明粗山羊草D组的同源性与普通小麦的D组同源性最高,同时,能在A、B引物中扩出特异性条带,说明粗山羊草D组与普通小麦的A、B基因组也有一定的同源性.UPGMA聚类结果表明,78份粗山羊草在遗传相似系数0.77时聚为6个主要类群,而且遗传聚类关系与材料的地理来源有一定的相关性.     

小麦AB基因组中一个重复序列的分离、定位与应用

利用102对微卫星引物对5份黑麦（Secale）、4份普通小麦（Triticum aestivum）和1份分枝小黑麦（Triticale）进行SSR分析,引物Xgwm614能在分枝小黑麦中扩增出一个387bp的特异DNA片段（记为FZ387,GenBank登录号为EF179137）,而黑麦未能扩增出。序列比对结果显示该片段与一粒小麦（T. monococcum）（AY485644）和栽培二粒小麦（T. turgidum）（AY494981）A基因组中Gypsy Ty3-LTR反转座子fatima的一部分分别有94%和95%同源性。根据序列同源性比对结果,在FZ387内部设计1对特异引物FaF和FaR。引物Xgwm614F和FaR能在含有A基因组的物种中扩增出约350bp的条带（记为A350）,而其不含A基因组的物种都未扩增出该条带。利用小麦二体和端体代换系材料对其进行定位,结果显示该片段分布在所有A染色体的长臂和断臂上。此外,引物FaF和Xgwm614R能在含有A、B或AB基因组的物种中扩增出约350bp的条带（记为AB350）,而不含AB基因组的材料未扩增出目标条带。利用这两对特异引物对小麦属近缘物种进行PCR扩增,发现只有中国春能够扩增出A350和AB350。序列比对结果和FZ387两侧SSR引物结合区的规律性变化表明该反转座子在进化上可能存在属间多样性和属内相似性。A350和AB350也可以分别作为分子标记检测A染色体和AB染色体。     

人工合成小麦农艺性状与SSR标记的关联分析（英文）

人工合成小麦是通过人工融合粗山羊草(Aegilops tauschii)(2n=2x=14,DD)的D基因组与普通硬粒小麦(Triticum aestivum)(2n=6x=42,AABBDD)的A、B基因组获得的一种新型六倍体小麦,是获得基因变异的有效工具。本研究通过构建含有86份人工合成小麦和24份常规小麦的自然群体,利用102对SSR标记与4个重要的农艺性状进行关联分析。共检测出660个等位变异,每个位点的等位变异数为3~11个,平均为4.6个。多态性信息量(PIC)范围为0.2477~0.8971,平均为0.7235。供试材料被划分为三个亚群。2015年和2016年分别发现20个、17个与4个性状相关的位点(P0.01)。2015年,解释率为0.0398~0.2472,2016年则为0.063 9~0.191 3。这些显著性标记丰富了小麦的遗传多样性,为小麦分子标记辅助育种提供了新的资源。     

小麦M染色体组的RELP标记

利用２９个小麦ＲＦＬＰ探针与６种限制性酶切的Ｍ染色体组ＤＮＡ进行分子杂交，获得了５５个Ｍ染色体组的ＲＦＬＰ标记，其中１５个与小麦ＡＢＤ染色体组相同，４０个染Ｍ染色体组的特殊标记，在顶荒山羊草和小麦－顶芒山羊草双二倍体以及小麦顶芒山羊草异代换系中稳定遗传     

在陕南圆锥小麦Wx蛋白亚基多态性研究中首次发现天然糯性类型

用双向SDS-PAGE和单向SDS-PAGE对六倍体 普通小麦(Triticum aestivum,AABBDD)Wx蛋白 的研究结果表明,在每个染色体组的第7同源群染 色体上有一个Wx位点:7A上的Wx-A1,7D上的 Wx-D1和从7B易位到4A上的Wx-Bl,因而六倍 体普通小麦有3种Wx蛋白.一些科研工作者筛选 到Wx-A1和Wx-B1缺失的“关东107”、Wx-D1缺 失的“白火麦”和一些Wx-B1缺失类型的材料.     

粘类小麦雄性不育系线粒体DNA的AFLP标记及SCAR转化

为了能在分子水平上有效鉴定具有粘果山羊草(Aegilops kotschyi)、偏凸山羊草(A.ventricosa)、普通小麦变种斯卑尔脱(Triticum spelta)细胞质雄性不育系及其保持系90-110和8222,提高其在杂交小麦(Triticum aestivum L.)研究与应用中的定向遗传改良,本研究对其线粒体DNA进行了扩增片段长度多态性(amplified fragment length polymorphism,AFLP)标记和序列特征性片段扩增区域(sequence characterized amplified region,SCAR)标记。通过AFLP标记方法,应用64对引物组合EcoRⅠ-NNN/MseⅠ-NNN对小麦同核异质雄性不育系和保持系进行扩增,共扩增出682条带,其中113条为多态性条带。引物E-AGG/M-CTA组合在粘果山羊草细胞质雄性不育系中扩增出一条大小约300 bp的特异性条带,对该特异条带进行回收、测序,利用Primer Premier 5.0软件重新设计SCAR引物,并对这3种类型同核异质小麦细胞质雄性不育系和保持系进行扩增,其中引物YW1在3种细胞质雄性不育系和保持系中都扩增出条带,而引物YW2仅在粘果山羊草细胞质雄性不育系扩增出一条198 bp的特异性片段,结果表明,已成功地将AFLP标记转化为操作简便、表现稳定的SCAR标记。此片段与小麦线粒体基因组有很高的同源性(同源性为99%),为烟酰胺腺嘌呤二核苷酸(NADH)脱氢酶基因(GenBank登录号:EU534409.1)上的序列,该酶是线粒体中氧化磷酸化的入口酶,与小麦细胞质雄性不育密切相关。本研究可以用于粘类小麦细胞质雄性不育系分子标记辅助育种,也为小麦细胞质种性鉴定提供了技术支撑和理论依据。     

六倍体小偃麦与普通小麦杂交后代的分子细胞遗传学检测

为了改良六倍体小偃麦,创制携带E组染色体优良基因的普通小麦新类型。本研究利用六倍体小偃麦与克旱9号杂交选育六倍体小偃麦的衍生系,在杂交后代中选择具有六倍体小偃麦优良农艺性状的普通小麦类型。结果表明:六倍体小偃麦与普通小麦杂交结实率低,平均为21.9%,但F2以后分离复杂,出现一些代换系、易位系,附加系和DE混合的染色体组。有些品系性状表现较好,如分蘖多、抗病、多小穗、多花等。按性状继代选择直至F5共筛选出13个品系即05-9-2、05-9-4、05-9-5、05-9-6、05-9-7、05-9-8、05-9-11、05-9-14、9-9-14、05-9-13、05-7-13、05-7-24、05-7-22。利用花粉母细胞减数分裂观察,分子检测方法、原位杂交技术对以上13个品系进行了鉴定。以期为进一步研究和利用E组染色体改良普通小麦提供理论基础。     

利用小麦微卫星引物建立偃麦草Ee染色体组特异SSR标记

选用40对小麦SSR引物对17份偃麦草(Thinopyrum sp．)、2份小麦(Triticum aestivum)材料进行了PCR扩增分析，从中筛选到引物Xgwm325能在不同偃麦草材料中扩增出4条长度分别为1400、440、120和100bp的特异DNA片段，可以作为偃麦草种质的特异SSR标记。利用小麦-二倍体长穗偃麦草(Th.elongatum)异代换系和异附加系对引物Xgwm325进行了扩增鉴定，结果只有100bp左右的片段出现在长穗偃麦草所有E^e组染色体上，该片段可以作为E^e染色体组的特异SSR标记。     

小麦杂种优势群研究III普通小麦和斯卑尔脱小麦微卫星分子标记遗传差异的研究

选用１５份我国不同生态区的普通小麦品种（系）及９份不同国家的斯尔脱小麦品种（系）,利用微卫星分子标记对小麦种间,品种（系）间遗传差异进行了研究,探讨扩大杂交小麦育种亲本遗传基础的途径。所利用的１８对微卫星引物的２４份材料中均有搁增产物,共扩增出分子量小于５００ｂｐ的条带４９５条,其中４６８条带（占９６．７８％）具有多态性,平均每个引物可拉增出２６．６条多态性带。研究发现,９份斯卑尔脱小麦微卫星多态     

高能混合粒子场诱发的小麦矮杆突变体的SSR分析

为了研究高能混合粒子场(CR)和γ射线两种不同处理方法诱变小麦产生的具有相同表型的突变体之间的分子差异,选用随机分布于小麦21对染色体上的114对微卫星(SSR)引物,对CR和γ射线处理冬小麦品种ZY9和ZH7获得的矮杆突变体M3代进行SSR分析。结果表明,CR处理产生的矮杆突变体的多态性位点主要分布在染色体2A、2B、2D、3D和5A上,而γ射线处理产生的矮杆突变体的多态性位点主要分布在染色体2A、2B、2D、4A和5A上;与γ射线处理相比,CR处理较容易产生扩增条带的增加和扩增条带长度的差异,不易产生扩增条带的缺失。序列分析表明,CR处理产生的变异主要是碱基的置换和插入,其中碱基T为易发生突变的碱基。CR诱变能够在DNA水平上导致小麦遗传物质变异,其诱变机制不同于γ射线,是一种有效的诱发突变新途径。     

Grain Quality of Emmer Wheat Derived Synthetic Hexaploid Wheats

The wild diploid goat grass (Aegilops tauschii Cosson), and the cultivated tetraploid emmer wheat (Triticum turgidum L. subsp. dicoccon (Schrank) Thell.) may be important sources of genetic diversity for improving hexaploid bread wheat (Triticum aestivum L.). Through interspecific hybridization of emmer wheat and Ae. tauschii, followed by chromosome doubling, it is possible to produce homozygous synthetic hexaploid wheat. Fifty-eight such synthetic hexaploids were evaluated for grain quality parameters: grain weight, length, and plumpness, grain hardness, total protein content, and protein quality (SDS-Sedimentation volume, SDS-S). Most synthetics showed semi-hard to hard grain texture. Results showed significant genetic variation among the synthetic hexaploids for protein content, SDS-S values, and grain weight and plumpness. Quality measurement values of synthetic hexaploids were regressed on corresponding values of the emmer wheat parents. With this offspring-parent regression, protein content and SDS-S values explained 8.7 and 28.8%, respectively, of the variation among synthetics, indicating a significant contribution from the emmer wheat parents for these traits. The synthetic hexaploids, in general, had significantly higher protein content (15.5%, on average) and longer grains than ‘Seri M82’, the bread wheat control (13.1% protein content). Synthetics with SDS-S values and grain weights higher than those of ‘Seri M82’ were also identified. Protein content among synthetics showed significantly negative correlations with grain weight and plumpness, but no correlation with SDS-S values. Despite these negative correlations, 10 superior synthetic hexaploid wheats, derived from nine different emmer wheat parents and with above average levels of protein content, SDS-S values, and either grain weight or plumpness, were identified. This study shows that genetic variation for quality in tetraploid emmer wheat can be transferred to synthetic hexaploid wheats and combined with plump grains and high grain weight, to be used for bread wheat breeding.     

Wheat artificial amphiploids involving the <Emphasis Type="Italic">Triticum timopheevii</Emphasis> genome: their studies,preservation and reproduction

The effective utilisation of available genetic resources of related species is essential for successful crops breeding and maintaining genetic variability within crops. Bread wheat, the basic cultivated wheat species, is an amphiploid (2n = 6x = 42) and, therefore, the production of new synthetic amphiploids using genomes of related species should reduce the difficulties caused by direct crossings, for example, between hexaploid wheat and diploid relatives. Hence, exploiting synthetic amphiploids is an effective and rapid way of introgressing desirable traits from related species into cultivated wheats. Some of the artificial amphiploids that already exist were produced 80 years ago. Yet little work has been done to highlight potential contamination and/or genetic changes during their conservation by genebanks. Thus, we utilised the electrophoresis of wheat endosperm storage proteins (gliadins) to check such amphiploid authenticity, and also where differences had been previously observed between synthetic wheat amphiploids. In addition, we checked putative amphiploid accessions where Triticum timopheevii (GGA^tA^t) was recorded as one of the parents. A synthetic species, T. timococcum produced by Kostov, together with a natural T. zhukovskyi found in Georgia (the former Soviet Union) were revealed to be identical according to our assays. The existence of several T. kiharae accessions independently produced by different authors was confirmed, and they exhibited polymorphism for a number of traits, including spike characters (awning, hairy glumes) and growth habit (spring vs. winter). The effective conservation of artificial amphiploids in genebanks is discussed.     

Identification of alleles for complex gene loci Glu-A1, Glu-B1, and Glu-D1, which code for high molecular weight subunits of glutenin in Japanese hexaploid wheat varieties

Seed storage proteins of Japanese wheat (Triticum aestivum) varieties were fractionated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to identify the alleles for complex gene loci, Glu-A1, Glu-B1, and Glu-D1, which code for high molecular weight (HMW) subunits of glutenin in Japanese hexaploid wheat varieties. These were identified by comparison of subunit mobility with those previously found in hexaploid wheat. Twenty-four different, major glutenin HMW subunits were identified, and each variety contained three to five subunits. Seventeen different glutenin subunit patterns were observed for 14 alleles in Japanese varieties. A catalog of alleles for the complex gene loci, Glu-A1, Glu-B1, and Glu-D1, that code for HMW subunits of glutenin in hexaploid wheat was compiled. Japanese varieties showed some special allelic variation in glutenin HMW subunits that was different from those in hexaploid wheats of other countries.     

Resistance to wheat leaf rust in Aegilops tauschii Coss. and inheritance of resistance in hexaploid wheat

A collection of 164 Aegilops tauschii accessions, obtained from Gatersleben, Germany, was screened for reaction to leaf rust under controlled greenhouse conditions. We have also evaluated a selection of synthetic hexaploid wheats, produced by hybridizing Ae. tauschii with tetraploid durum wheats, as well as the first and second generation of hybrids between some of these resistant synthetic hexaploid wheats and susceptible Triticum aestivum cultivars. Eighteen (11%) accessions of Ae. tauschii were resistant to leaf rust among which 1 was immune, 13 were highly resistant and 4 were moderately resistant. Six of the synthetic hexaploid wheats expressed a high level of leaf rust resistance while four exhibited either a reduced or complete susceptibility compared to their corresponding diploid parent. This suppression of resistance at the hexaploid level suggests the presence of suppressor genes in the A and/or B genomes of the T. turgidum parent. Inheritance of leaf rust resistance from the intercrosses with susceptible bread wheats revealed that resistance was dominant over susceptibility. Leaf rust resistance from the three synthetics (syn 101, syn 701 and syn 901) was effectively transmitted as a single dominant gene and one synthetic (syn 301) possessed two different dominant genes for resistance.     

Morphological spike diversity of Omani wheat

Little is known about the diversity of field crops in Oman. The objective of this study therefore was to characterize wheat accessions from this country using individual spikes collected from different wheat cultivation areas. The phenotypic assessment of 15 qualitative and 17 quantitative characters showed variations among Omani wheat landraces. The standardized phenotypic diversity index (H′) was with 0.66 higher for quantitative characters than for qualitative characters (0.52) in tetraploid wheats and with 0.63 and 0.62, respectively, in hexaploid wheats. Overall, the morphological data revealed a surprisingly high diversity among landraces and showed that simple morphological characters can be used for an effective characterization of diversity in Omani wheat.     

Powdery mildew resistance in Aegilops tauschii coss. and synthetic hexaploid wheats

Summary A collection of 400 Ae. tauschii (syn. Ae. squarrosa) Coss. accessions were screened for powdery mildew resistance based on the response patterns of 13 wheat cultivars/lines possessing major resistance genes to nine differential mildew isolates. 106 accessions showed complete resistance to all isolates, and 174 accessions revealed isolate-specific resistance, among which were 40 accessions exhibiting an identical response pattern as wheat cultivar Ulka/^*8Cc which is known to possess resistance gene Pm2. Expression of both complete and isolate-specific resistance from Ae. tauschii was observed in some synthetic hexaploid wheats derived from four mildew susceptible T. durum Desf. parents, each crossed with five to 38 resistant diploid Ae. tauschii accessions. Synthetic amphiploids involving different combinations of T. durum and Ae. tauschii generally showed a decrease in resistance compared with that expressed by the Ae. tauschii parental lines.     

Genetic diversity of HMW glutenin subunits in diploid,tetraploid and hexaploid <Emphasis Type="Italic">Triticum</Emphasis> species

The genetic variations of high-molecular-weight (HMW) glutenin subunits in 1051 accessions of 13 Triticum subspecies were investigated using sodium dodecyl sulfate polyacrylamide-gel electrophoresis. A total of 37 alleles were detected, resulting in 117 different allele combinations, among which 20, 68 and 29 combinations were observed in diploid, tetraploid and hexaploid wheats, respectively. Abundance and frequency of allele and combinations in tetraploid wheats were higher than these in hexaploid wheats. Allele Glu-A1c was the most frequent subunit at Glu-A1 locus in tetraploid and hexaploid wheats. Consequently, the results also suggested that the higher variations occurred at Glu-B1 locus compared to Glu-A1 and Glu-D1. Therefore, carthlicum wheat possessing the allele 1Ay could be presumed a special evolutional approach distinguished from other tetraploid species. Furthermore, this provides a convenient approach of induction of the 1Ay to common wheat through direct cross with carthlicum wheat. Alleles Glu-B1c and Glu-B1i generally absent in tetraploid wheats were also found in tetraploid wheats. Our results implied that tetraploid and hexaploid wheats were distinguished in dendrogram, whereas carthlicum and spelta wheats and however displayed the unique performance. In addition, founder effect, no-randomness of diploidization, mutation and artificial selection could cause allele distribution of HMW-GS in Triticum. All alleles of HMW-GS in Triticum could be further utilized through hybrid in the quality improvement of common wheat.     

Towards allelic diversity in the storage proteins of old and currently growing tetraploid and hexaploid wheats in Portugal

Using sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS–PAGE), the different alleles encoded at the 6 glutenin loci and 3 ω-gliadin loci were identified from a set of 134 hexaploid and 128 tetraploid wheat accessions mainly grown in Portugal. In the hexaploid wheats (T. aestivum L.), a total of 56, 42 and 36 patterns were observed for high molecular weight-glutenin subunits (HMW-GS), low molecular weight-glutenin subunits (LMW-GS) and ω-gliadins respectively. For HMW-GS encoded at Glu-A1, Glu-B1 and Glu-D1 loci, 4, 10 and 6 alleles were observed, respectively. LMW-GS displayed similar polymorphism, as Glu-A3, Glu-B3 and Glu-D3 loci, which comprises 5, 9 and 3 alleles. Twenty-four alleles were observed for ω-gliadins found at Gli-A1, Gli-B1 and Gli-D1 loci with, 5, 16 and 3 alleles respectively. For tetraploid collection fifty different alleles were identified for the seven loci studied Glu-A1 (3), Glu-B1 (13), Glu-A3 (6), Glu-B3 (7), Glu-B2 (2), Gli-A1 (5) and Gli-B1 (14). The genetic distances within hexaploid and tetraploid wheats were presented using cluster representation. The mean value of genetic variation indices (H) for wheat storage protein loci was slightly lower in current commercially available varieties (0.592) and highest for old varieties (0.574).     

The relationship between high-molecular-weight glutenin subunit composition and the quality of Japanese hexaploid wheat lines

To reveal the high-molecular-weight (1-1MW) glutenin subunit composition, the seed storage proteins of 40 Japanese wheat (Triticum aestivum) lines were fractionated by sodium dodecyl sulfate- polyacrylamide gel electrophoresis to determine their HMW glutenin subunit composition. These were identified by comparison of subunit mobility with that previously found in hexaploid wheat. Twelve different, major glutenin HMW subunits were identified. Each line contained three to five subunits, and 11 different glutenin subunit patterns were observed for 11 alleles in Japanese lines. The Glu-1 quality scores were not particularly high for most of the Japanese wheats in the southern part of Japan (Kyushu district). However, the Glu-1 quality scores of several wheat lines in the Hokkaido area (north Japan) were high. South Japanese wheat lines showed specialty allelic variation in the glutenin HMW 145 kfla subunit, different from those in non-Japanese hexaploid wheats.     

Analysis of fatty acid steryl esters in tetraploid and hexaploid wheats: identification and comparison between chromatographic methods

Fatty acid steryl esters (FASE) in whole meal of 14 genotypes of tetraploid wheats (Triticum dicocconand T. durum) and 17 genotypes of hexaploid wheats (T. spelta and T. aestivum) were analyzed using different chromatographic strategies. By both GC-FID and HPLC-ELSD, tetraploid wheats are lacking two major peaks. The amounts of FASE, calculated on the basis of the GC-FID analysis, were double in hexaploid species as compared to tetraploids (40 and 20 mg/100 g db, respectively). HPLC with ESI-MS detection enabled the identification of FASE by the characteristic fragmentations and ion-adducts of each molecule. The distribution of steryl residues was not different between the wheat species: the main class of steryl derivatives found was the beta-sitosteryl derivatives, followed by campesteryl derivatives with small amounts of stigmasteryl esters. The esterified fatty acids explain the difference between the hexaploid and tetraploid wheats. In particular, small amounts of campesteryl and beta-sitosteryl, while no trace of stigmasteryl palmitates, were found in T. durum or its hulled ancestor T. dicoccon. Steryl oleates were not detectable in T. aestivum or its hulled ancestor T. spelta, which is consistent with the filogenesis of tetraploid and hexaploid species. Both chromatographic techniques (GC and HPLC) showed that FASE are useful to discriminate between hexaploid and tetraploid wheats from both qualitative and quantitative points of view.