高分子量谷蛋白（HMW-GS）是决定小麦加工品质的关键种子储藏蛋白类型。Dx5+Dy10是公认的优质HMW-GS组合，但Dy10亚基对加工品质的作用尚不清楚。本研究利用一份Dy10缺失突变体（含Dy10-null等位变异）和体外添加Dy10蛋白的方法研究了Dy10亚基的加工品质效应。Dy10-null等位变异可正常转录，但不表达蛋白。构建近等基因系，发现Dy10-null等位变异显著降低面筋指数、Zeleny沉降值、形成时间和稳定时间，弱化面团强度；降低HMW-GS含量，提高醇溶蛋白含量，降低谷醇比，提升饼干品质。体外添加纯化的Dy10蛋白，发现Dy10对饼干品质有负作用。综上，Dy10亚基与小麦面团强度密切相关，Dy10-null等位变异对弱筋小麦育种具有价值。

提高小麦产量是全球小麦育种者的长期目标。发掘优良遗传资源，解析小麦重要农艺性状的遗传基础，是小麦高产育种的必经之路。本研究评价了两年七个环境中由156个育成品种和77个地方品种组成的四川小麦自然群体的9个重要农艺性状表现。农艺性状调查结果表明，地方品种分蘖较多，穗粒数（KNS）较高，育成品种千粒重（TKW）和穗粒重（KWS）较高。9个农艺性状的广义遗传力（H ²）在0.74到0.95之间。利用来自小麦55K SNP芯片的43198个单核苷酸多态性（SNP）标记进行群体结构分析可以将自然群体分为三组。基于混合线性模型Q+K方法的全基因组关联分析（GWAS）共鉴定出67个数量性状位点（QTL）。本研究主要对三个重要性状的QTL进行了分析，即分别检测到的可育分蘖数（FTN）位点QFTN.sicau-7BL.1的四种单倍型、KNS位点QKNS.sicau-1AL.2的三种单倍型和TKW位点QTKW.sicau-3BS.1的四种单倍型。从2002—2013年区域试验的42个品种的产量表现来看，FTN-Hap2、KNS-Hap1和TKW-Hap2分别是每个QTL中的优良单倍型。具有三个优良单倍型的品种相比具有两个或一个优良单倍型的品种产量更高。此外，基于每穗粒数的QTL位点 QKNS.sicau-1AL.2开发了连锁的KASP-AX-108866053标记能在2018年至2021年区域试验中鉴定63个品种的三种单倍型（或等位基因）。这些遗传位点和连锁标记可用于标记辅助选择或基于图谱的基因克隆，用于小麦产量的遗传改良。

本研究基于小麦Wheat55K SNP芯片鉴定到两个主效且稳定表达的小穗数QTL。其中，QSns.sau-2SY-2D.1在之前的研究中已经被报道，而本研究中新鉴定到一个QTL（QSns.sau-2SY-7A），我们对其进行了深入分析。QSns.sau-2SY-7A的LOD值较高，介于4.46至16.00之间，解释10.21-40.78％的表型变异。QSns.sau-2SY-7A位于染色体臂7AL上4.75-cM的区间，侧翼标记为AX-110518554和AX-110094527。我们对两个主效QTL的贡献和相互作用进行了深入的分析和讨论。我们进一步开发一个与QSns.sau-2SY-7A紧密连锁的KASP标记，在一个F_2:3群体和一个包含101个小麦高代育种品系的自然群体中对该QTL的效应进行了验证。此外，在QSns.sau-2SY-7A定位区间中，预测到一个水稻中报道的调控小穗数的同源基因WAPO1，结合前人报道，该基因很有可能是该位点的候选基因。综上所述，本研究系统揭示了被广泛用于育种亲本的品系‘20828’的多小穗数遗传基础，并开发获得紧密连锁标记，有助于后续主效QTL的精细定位和育种利用。

了解小麦品质相关性状的遗传基础有助于对小麦品质进行改良，本实验测定了多环境下236份小麦种质资源（包括 160 个栽培品种和76个地方品种）的蛋白质含量（GPC）、淀粉含量（GSC）和湿面筋含量（WGC），并使用 55K小麦芯片进行了混合线性模型 (MLM)分析。结果共鉴定了 12 个稳定的 QTL/SNP，与GPC、GSC和WGC 相关的位点分别有3个、7个和2个 QTL，它们分别位于1B、1D、2A、2B、2D、3B、3D、5D 和 7D 染色体上；表型变异解释 (PVE) 范围从4.2 至10.7%。与之前报道的 QTL/基因相比，5 个 QTL（QGsc.sicau-1BL、QGsc.sicau-1DS、QGsc.sicau-2DL.1、QGsc.sicau-2DL.2、QWgc.sicau-5DL）是潜在的新位点。本实验着重关注了位于5D染色体上与湿面筋浓度相关的稳定QTL，并成功开发了SNP AX-108770574 和AX-108791420 两个KASP 标记。其中AX-108770574中含有A-等位基因和AX-108791420中含有T-等位基因的品种表型显着高于(P<0.01)含有湿面筋浓度G-等位基因或C-等位基因的地方品种，表明开发的KASP 标记可用于分子育种，改良小麦品质。

本研究利用一个人工合成小麦与普通小麦品种构建的重组自交系，构建了一张包含28个FISH多态性标记和超过150000个单核苷酸多态性（single nucleotide polymorphism，SNP）标记的整合图谱。锚定在整合图谱的28个FISH标记中，20个FISH标记的共分离SNP标记推断的物理位置与原位杂交的物理位置一致。另外8个位置不一致的FISH标记是由亲本含有的易位染色体（1R/1B和1A/7A）或臂内倒位染色体（4A）所导致。9个在于中国春染色体上也具有杂交信号的FISH标记中，8个FISH标记的杂交信号位置与通过参考基因组序列锚定的物理位置一致，表明当前中国春参考基因组对重复序列的组装效果较好。因此，整合图谱对定位重复序列以及提高对基因组重复序列的组装精度方面具有一定利用价值。

下节间直径（UID）是与小麦穗部发育和丰产性相关的重要形态性状。而我们对其遗传基础的了解知之甚少。本文在5个小麦重组自交系（RIL）群体中利用高密度遗传图谱鉴定了控制UID的数量性状位点（QTL）。在5个RIL群体中共检测到25个UID QTL，分别位于1A、1D（3个QTL）、2B（2）、2D（3）、3B、3D、4A、4B（3）、4D、5A（5）、5B（2）、6B、7D染色体上。其中，5个主效且稳定的QTL：QUid.sau-2CN-1D.1、QUid.sau-2SY-1D、QUid.sau-QZ-2D、QUid.sau-SC-3D和QUid.sau-AS-4B分别在5个RIL群体的多个环境中检测到。QUid.sau-2CN-1D、QUid.sau-2SY-1D与QUid.sau-SC-3D 为三个新的UID 位点。我们进一步开发了与主效QTL紧密连锁的竞争性等位基因特异性PCR（KASP）标记，用于构建近等基因系（NILs）。此外，我们还在主效QTL的物理区间内预测了候选基因，这些候选基因大多与植物发育和水分运输有关。以中国春为参考基因组，我们对定位到的主效QTL的物理区间进行了比较，结果表明，QUid.sau-2CN-1D.1和QUid.sau-2SY-1D可能是等位基因，进一步证实了它们的真实性和有效性。本文也对UID与其他农艺性状的相关关系及UID的大小进行了讨论。总体而言，我们的研究结果剖析了小麦UID的潜在遗传基础，为这些QTL的进一步精细定位和图位克隆奠定了基础。

Synthetic hexaploid wheat (SHW), possesses numerous genes for drought that can help breeding for drought-tolerant wheat varieties.  We evaluated 10 root traits at seedling stage in 111 F₉ recombinant inbred lines derived from a F₂ population of a SHW line (SHW-L1) and a common wheat line, under normal (NC) and polyethylene glycol-simulated drought stress conditions (DC).  We mapped quantitative trait loci (QTLs) for root traits using an enriched high-density genetic map containing 120 370 single nucleotide polymorphisms (SNPs), 733 diversity arrays technology markers (DArT) and 119 simple sequence repeats (SSRs).  With four replicates per treatment, we identified 19 QTLs for root traits under NC and DC, and 12 of them could be consistently detected with three or four replicates.  Two novel QTLs for root fresh weight and root diameter under NC explained 9 and 15.7% of the phenotypic variation respectively, and six novel QTLs for root fresh weight, the ratio of root water loss, total root surface area, number of root tips, and number of root forks under DC explained 8.5–14% of the phenotypic variation.  Here seven of eight novel QTLs could be consistently detected with more than three replicates.  Results provide essential information for fine-mapping QTLs related to drought tolerance that will facilitate breeding drought-tolerant wheat cultivars.

Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most damaging diseases of wheat. Chinese wheat cultivar Mianmai 41 showed high resistance against most of the prevailing Pst races in China. Genetic analysis of the F1, F2 and F2:3 populations from a cross between Mianmai 41 and a susceptible line Mingxian 169 indicated that resistance to Pst race CYR32 was conferred by a single dominant gene, temporarily designated as YrMY41. Molecular marker analysis placed the gene on chromosome 1B near the centromere. Six co-dominant genomic SSR markers Xwmc329, Xwmc406, Xgwm18, Xgwm131, Xgwm413, and Xbarc312, and one STS marker Xwe173 linked with the resistance gene. The two closest flanking SSR markers were Xgwm18 and Xwmc406, with genetic distances of 2.0 and 4.9 cM, respectively. A seedling test with 29 Pst isolates indicated the reaction patterns of Mianmai 41 were different from those of lines carrying Yr3, Yr9, Yr10, Yr15, Yr26, and YrCH42 on chromosome 1B. Allelic tests indicated that YrMY41 is likely a new allele at Yr26 locus.

Starch is the major carbohydrate in oat (Avena sativa L.) and starch formation requires the coordinated actions of several synthesis enzymes. In this study, the granule morphology, composition and physicochemical properties of oat starch, as well as the expressions of starch synthesis genes were investigated during oat endosperm development. Under the scanning electron microscopy (SEM), we observed that the unique compound granules were developed in oat endosperms at 10 days post anthesis (DPA) and then fragmented into irregular or polygonal simple granules from 12 DPA until seed maturity. The amylose content, branch chain length of degree of polymerization (DP=13–24), gelatinization temperature and percentage of retrogradation were gradually increased during the endosperm development; whereas the distribution of short chains (DP=6–12) were gradually decreased. The relative expressions of 4 classes of 13 starch synthesis genes characterized in this study indicated that three expression pattern groups were significantly different among gene classes as well as among varied isoforms, in which the first group of starch synthesis genes may play a key role on the initiation of starch synthesis in oat endosperms.

Aegiliops tauschii is classified into two subspecies: Ae. tauschii ssp. tauschii and Ae. tauschii ssp. strangulata. Novel genetic variations exist in Ae. tauschii ssp. tauschii that can be utilized in wheat improvement. We synthesized a hexaploid wheat genotype (SHW-L1) by crossing an Ae. tauschii ssp. tauschii accession (AS60) with a tetraploid wheat genotype (AS2255). A population consisting of 171 F8 recombinant inbred lines was developed from SHW-L1 and Chuanmai 32 to identify QTLs associated with agronomic traits. A new genetic map with high density was constructed and used to detect the QTLs for heading date, kernel width, spike length, spikelet number, and thousand kernel weight. A total of 30 putative QTLs were identified for five investigated traits. Thirteen QTLs were located on D genomes of SHW-L1, six of them showed positive effect on agronomic traits. Chromosome region flanked by wPt-6133–wPt-8134 on 2D carried five environment-independent QTLs. Each QTL accounted for more than 10% phenotypic variance. These QTLs were highly consistent across environments and should be used in wheat breeding.

γ-Gliadins are an important component of wheat seed storage proteins. Four novel γ-gliadin genes (Gli-ng1 to Gli-ng4) were cloned from wheat (Triticum aestivum) and Aegilops species. The novel γ-gliadins were much smaller in molecular size when compared to the typical γ-gliadins, which was caused by deletion of the non-repetitive domain, glutamine-rich region, 3´ part of the repetitive domain, and 5´ part of the C-terminal, possibly due to illegitimate recombination between the repetitive domain and the C-terminal. As a result, Gli-ng1 and Gli-ng4 only contained two and three cysteine residues, respectively. Gli-ng1, as the representative of novel γ-gliadin genes, has been sub-cloned into an Escherichia coli expression system. SDS- PAGE indicated that the both cysteine residues of Gli-ng1 could participate in the formation of intermolecular disulphide bonds in vitro. Successful cloning of Gli-ng1 from seed cDNA of T. aestivum cv. Chinese Spring suggested that these novel γ-gliadin genes were normally transcribed during the development of seeds. Phylogenic analysis indicated that the four novel γ-gliadin genes had a closer relationship with those from the B (S) genome of wheat.

Micronutrient malnutrition affects over three billion people worldwide, especially women and children in developing countries. Increasing the bioavailable concentrations of essential elements in the edible portions of crops is an effective resolution to address this issue. To determine the genetic factors controlling micronutrient concentration in wheat, the quantitative trait locus (QTL) analysis for iron, zinc, copper, manganese, and selenium concentrations in two recombinant inbred line populations was performed. In all, 39 QTLs for five micronutrient concentrations were identified in this study. Of these, 22 alleles from synthetic wheat SHW-L1 and seven alleles from the progeny line of the synthetic wheat Chuanmai 42 showed an increase in micronutrient concentrations. Five QTLs on chromosomes 2A, 3D, 4D, and 5B found in both the populations showed significant phenotypic variation for 2-3 micronutrient concentrations. Our results might help understand the genetic control of micronutrient concentration and allow the utilization of genetic resources of synthetic hexaploid wheat for improving micronutrient efficiency of cultivated wheat by using molecular marker-assisted selection.

Waterlogging is a widespread limiting factor for wheat production throughout the world. To identify quantitative trait loci (QTLs) associated with waterlogging tolerance at early stages of growth, survival rate (SR), germination rate index (GRI), leaf chlorophyll content index (CCI), root length index (RLI), plant height index (PHI), root dry weight index (RDWI), shoot dry weight index (SDWI), and total dry weight index (DWI) were assessed using the International Triticeae Mapping Initiative (ITMI) population W7984/Opata85. Significant and positive correlations were detected for all traits in this population except RLI. A total of 32 QTLs were associated with waterlogging tolerance on all chromosomes except 3A, 3D, 4B, 5A, 5D, 6A, and 6D. Some of the QTLs explained large proportions of the phenotypic variance. One of these is the QTL for GRI on 7A, which explained 23.92% of the phenotypic variation. Of them, 22 alleles from the synthetic hexaploid wheat W7984 contributed positively. These results suggested that synthetic hexaploid wheat W7984 is an important genetic resource for waterlogging tolerance in wheat. These alleles conferring waterlogging tolerance at early stages of growth in wheat could be utilized in wheat breeding for improving waterlogging tolerance.

Genetic diversity of 62 Sichuan wheat landraces accessions of China was investigated by agronomic traits and SSR markers. The landrace population showed the characters of higher tiller capability and more kernels/spike, especially tiller no./plant of six accessions was over 40 and kernels/spike of three accessions was more than 70. A total of 547 alleles in 124 polymorphic loci were detected with an average of 4.76 alleles per locus by 114 SSR markers. Parameters analysis indicated that the genetic diversity ranked as genome A> genome B > genome D, and the homoeologous groups ranked as 5>4>3>1>2>7>6 based on genetic richness (Ri). Furthermore, chromosomes 2A, 1B and 3D had more diversity than that of chromosomes 4A, 7A and 6B. The variation of SSR loci on chromosomes 1B, 2A, 2D, 3B, and 4B implied that, in the past, different selective pressures might have acted on different chromosome regions of these landraces. Our results suggested that Sichuan common wheat landraces is a useful genetic resource for genetic research and wheat improvement.

The Hina gene is one of the two known Hin genes for hardness, and its RNA expression is correlated with grain hardnessand dry matter digestibility variation. In this study, only one clone of Hina gene was obtained from one barley accession.A total of 121 Hina gene sequences were isolated from 121 wild barley (Hordeum spontaneum) accessions in Israel, Iran,and Turkey, and then their molecular characteristics were compared with 97 Hina gene sequences from 74 cultivatedbarley (H. vulgare) lines in Europe and 23 landrace (H. vulgare) with global distribution and other 26 Hina gene sequencesfrom cultivated barleys (H. vulgare) with unknown global distribution. Cis-acting regulatory element (CARE) searchingrevealed that there were different types of regulatory element for the Hina gene in wild and landrace/cultivated barleys.There were six consistent cis-acting binding sites in wild and landrace/cultivated barleys, whereas 8 to 16 inconsistentTATA-boxes were observed. In addition, three special elements (E2Fb, Sp1, and boxS) were only observed in wild barley,while one (AT1-motif) was only found in landrace/cultivated barley. Forty-four deduced amino acid sequences of HINAfrom wild and landrace/cultivated barleys were obtained by deleting repetitive amino acid sequences, and they wereclustered into two groups on the basis of Neighbor-Joining analysis. However, there was no obvious difference in theamino acid sequences of HINA between wild and landrace/cultivated barleys. Comparing to protein secondary structureof wheat PINA, it was indicated that HINA also existed a signal peptide. In addition, HINA was a hydrophilic protein onthe basis of the protein properties and composition.