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。

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。

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。

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.

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.

Pasteurella multocida, a Gram-negative nonmotile coccobacillus, is the causative agent of fowl cholera, bovine hemorrhagic septicemia, enzoonotic pneumonia and swine atropic rhinitis. Two filamentous hemagglutinin genes, fhaB1 and fhaB2, are the potential virulence factors. In this study, an inactivation fhaB1 mutant of P. multocida in avian strain C48-102 was constructed by a kanamycin-resistance cassette. The virulence of the fhaB1 mutant and the wild type strain was assessed in chickens by intranasal and intramuscular challenge. The inactivation of fhaB1 resulted in a high degree of attenuation when the chickens were challenged intranasally and a lesser degree when challenged intramuscularly. The fhaB1 mutant and the wild type strain were investigated their sensitivity to the antibody-dependent classical complement-mediated killing pathway in 90% convalescent chicken serum. The fhaB1 mutant was serum sensitive as the viability has reduced between untreated serum and heat inactivated chicken serum (P<0.007). These results confirmed that FhaB1 played the critical roles in the bacterial pathogenesis and further studies were needed to investigate the mechanism which caused reduced virulence of the fhaB1 mutant.

The free putrescine (Put) content, the hydrogen peroxide (H2O2) content and the polyamine oxidase (PAO) activity in roots of Malus hupehensis Rehd. var. pinyiensis Jiang (PYTC) were significantly increased, and reached its peak at 1, 2 and 6 h, respectively, under cadmium treatment. The free spermine (Spm) and spermidine (Spd) contents were dramatically decreased, and reached the minimum value at 4-6 h, then remained relatively stable. The change in total free polyamines (PAs) content was consistent with that of free Put. The number of root dead cells was gradually increased after treatment for 24 h, and the typical characteristics of programmed cell death (PCD) were displayed at 48 h. Throughout the Cd treatment process, changes in PAs metabolism appeared to be prior to cell death increase, and the H2O2 content was always maintained at a high level. These results indicated that polyamines could initiate cell death by generating H2O2 in roots of Malus hupehensis Rehd. under CdSO4 stress.

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.