Protective effects of nitric oxide on salt stress-induced oxidative damage to wheat (Triticum aestivum L.) leaves

The changes of chlorophyll and malondialdehyde (MDA) contents, plasma membrane permeability confirmed that 0.1 and 1 mmol/L sodium nitroprusside (SNP), a donor of nitric oxide (NO) in vivo, could markedly alleviate the oxidative damage to wheat (Triticum aestivum L.) leaves induced by 150 and 300 mmol/L NaCl treatments, respectively. Further results proved that NO significantly enhanced the activities of Superoxide dismutase (SOD) and catalase (CAT), both of which separately contributed to the delay of O ₂ ⁻ and H₂O₂ accumulation in wheat leaves under salt stress. Meanwhile, the accumulation of proline was apparently accelerated. Therefore, these results suggested that NO could strongly protect wheat leaves from oxidative damage caused by salt stress.     

激素对小麦幼穗组织培养效果的影响研究

分析了激素对两个基因型小麦幼穗组织培养效果的影响,结果表明,愈伤组织诱导率在每个组合中均可达100％,诱导培养基中加入2,4-D对植株再生和绿点分化频率的效果要显著优于Picloram,在所采用的有效2,4D浓度范围内,随着浓度的升高,绿苗的再生频率呈现上升的趋势,2,4-D的量为4.5mg／L时,植株的再生频率平均可以达到45％左右。     

种植红豆草和春小麦对土壤可溶性盐分运移的影响

通过田间试验，测定了种植红豆草（Onobrychis viciaefolia）和春小麦（Triticum aestivum）对土壤可溶性盐分运移的影响．结果表明：不同绿色覆盖方式对0～20cm土层都具有明显的抑盐效应，随着地上生物量的增加，土壤表层的可溶性盐分下降幅度达16．4％～30．5％；在生育期内，红豆草的抑盐效应（0～20cm土层）较小麦强，红豆草使0～80cm土层脱盐率达23．4％，而小麦使0～80cm土层积盐率达14．2％；单作小麦收获后的空闲地．土壤表层盐分上升速度较裸地快．     

两种小麦的原生质体培养再生植株

报道两种基因型小麦昌乐5号和山农587胚性悬浮细胞系的建立和原生质体再生植株。小麦昌乐5号和山农587的胚性愈伤组织继代一年以后形成部分颗粒状和粉粒状结构,可用于悬浮培养。当分散好、生长快的胚性悬浮细胞系形成后,即可作为原生质体培养的材料。较长时间的悬浮培养容易使材料的胚性丧失,昌乐5号的胚性悬浮细胞系20天左右建成,其原生质体再生植株的频率为14/10~5(再生植株数/植板的原生质体数);而山农587的悬浮培养物需5个月以后才能用于原生质体培养,其原生质体再生植株的频率仅为4/10~6。     

盐胁迫下小麦新品系89122的抗氧化酶活性和内源ABA含量变化的研究

利用花粉管通道法获得的转基因耐盐小麦新品系89122和其受体“陇春13”,在盐胁迫处理下,测定盐胁迫后89122和“陇春13”无性细胞系的抗氧化酶活性的变化和脱落酸的变化,结果表明,89122较其受体“陇春13”能维持较高的SOD,POD,CAT活性,ABA含量明显高于受体。     

盐胁迫下小麦新品系89122的抗氧化酶类活性变化的研究

利用受粉后的花粉管通道将高梁ＤＮＡ导入普通小麦陇春１３号,在其后代中出现了广泛变异,从中选育出已稳定遗传的丰产、抗逆性强的新品系８９１２２。经大田和盐池鉴定,８９１２２的耐盐性明显高于陇春１３号,用ＮａＣｌ（０,０．１,０．１５,０．２,０．２５ｍｏｌ／Ｌ）处理８９１２２和陇春１３号幼苗７ｄ,测定盐胁迫后其幼苗中抗氧化酶类活性的变化。结果发现,转基因小麦８９１２２较其受体陇春１３号能维持较高的ＳＯ     

NO供体SNP浸种显著缓解盐胁迫对小麦幼苗的氧化损伤

以小麦品种德抗961为材料,用NO供体硝普钠(SNP)浸种研究外源NO对盐胁迫下小麦幼苗氧化损伤的影响.结果表明:0.02~0.1 mmol/L的SNP浸种24 h对盐胁迫下小麦幼苗生长的抑制均有一定程度的缓解作用,其中以0.06 mmol/L的SNP浸种预处理效果最好.并从叶绿素含量、质膜相对透性、MDA含量3个方面证实:0.06 mmol/L的SNP浸种预处理对盐胁迫下的小麦叶片氧化损伤有明显的缓解作用.同时能显著诱导盐胁迫下小麦叶片SOD活性、APX活性、CAT活性,从而减轻盐胁迫下小麦叶片的氧化损伤.     

Chromosome sorting and its applications in common wheat (Triticum aestivum) genome sequencing

The large genome size (～17000 Mb) and complicated DNA structures of common wheat (Triticum aestivum) hamper its genome sequencing.By means of flow cytometry,systematic investigations on individual chromosome sorting have been carried out to construct chromosome-specific bacterial artificial chromosome (BAC) libraries since the 1980s.Several wheat chromosome-specific BAC libraries,such as chromosome 3B,three D genome chromosomes (1D,4D and 6D),and the short arm of chromosome 1B,have been developed,and the ph...     

Plant regeneration from intergeneric asymmetric hybridization between wheat (Triticum aestivum L.) and Russian wildrye (Psathyrostachys juncea (Fisch.) Nevski) and wheat grass (Agropyron elongatum (Host) Nevski)

Particular attention has been paid to the donor-recipient method in the work of plant somatic hybridization. γ-or X-ray was generally used to irradiate one of the parents(donor) in order to obtain hybrids or asymmetric nuclear hybrids. But no application of ultraviolet rays (UV) has been reported yet. In the field of somatic hybridization of cereals, many     

Molecular identification of asymmetric somatic hybrids between wheat and Italian ryegrass

Sexual incompatibility between common wheat and Italian ryegrass was an obstacle for transferring useful traits from italian ryegrass to wheat. In order to use those desirable genetic resources to improve wheat and to create new cytoplasmic germplasm, the protoplasts of wheat and Italian ryegrass were successfully electrofused and the somatic hybrid plants were regenerated. Examination with 6 restriction enzymes, 13 probes including 9 mtDNA probes (H454, Pst24, B30, Pro I, 490, B342, pHJ2-7-1, B376, 7), 3 cpDNA probes (pHvc p1, pHvc p5 and pHvc p8) and one nuclear DNA probe-- pTA71 (rDNA) in total 73 enzyme/ probe combinations revealed rich polymorphism between the fusion partners. RFLP analysis indicated that approximately 93.4% of the regenerated plants were true somatic hybrids. AFLP analysis implied that the somatic hybrids were highly asymmetric. The RFLP analysis using mt- and cpDNA specific probes also demonstrated the non-coexistence of mitochondria and chloroplasts from the fusion partners in the somatic hybrid cells.     

不同基因型小麦成熟胚盾片组织培养效果研究

不同基因型及其外植体的愈伤组织诱导和植株分化研究是建立高效植株再生和遗传转化系统的基本条件。文章首次以去胚的成熟胚盾片为外植体材料,对10个小麦基因型进行了离体操作。结果显示:愈伤组织诱导率平均可达96.5%,10个基因型的愈伤组织都能分化出绿苗,分化频率最高可达10.5%,没有白苗化现象;根的分化与绿点、绿苗的分化之间具有显著的相关性;鄂恩1号的植株再生能力显著优于其它基因型,其植株再生系统已具备了遗传转化的基本要求。     

野生大豆DNA导入小麦及RAPD分子验证

利用花粉管通道法将野生大豆总DNA导入小麦，以期获得变异系小麦．对小麦球蛋白的SDS—PAGE，印迹表明，冬小麦T2l6#产生了新的蛋白亚基，其分子量为78kD，而有的变异品系一些蛋白亚基消失了；凯氏定氮法和氨基酸分析表明小麦后代T216#的总蛋白含量增加，其氨基酸组成，尤其是赖氨酸含量明显提高．RAPD分析结果表明，新品系基因组出现多态性，并具有供体特异性DNA带，这些变异现象表明该小麦品系为转基因后代．本实验为选育高蛋白、优质的新小麦品种提供了途径．     

应用亲缘系数分析四川小麦种质资源的遗传多样性

对代表四川小麦优良种质的40个小麦品种进行了亲缘系数分析，探讨遗传多样性，结果表明，约60％品种组合间的COP值为0，所有供试品种COP值变异范围为0．00－0．75，平均值仅为0．08，表明大多数品种在系谱上的遗传关系很小或无遗传关系，通过COP聚类分析将供试材料聚为6个类群，2个引进品种各自聚为一个类群，其余38个品种分别以繁6，阿勃，绵阳11号，成都光头4个优势亲本聚为不同的大类群与亚类群，分析认为，供试品种间系谱上的遗传差异较大，遗传多样性较高，文中对不同育种单位及不同时期小麦遗传多样性进行了分析。     

Expression of lysine-rich protein gene and analysis of lysine content in transgenic wheat

Expression vector pBPC102, which carries winged bean lysine-rich protein (wblrp) gene and dihydropicolinate synthase (DHDPS) gene, was transferred into hexaploid winter wheat cv. Jinghua No.l, Jing411, You899 and Yangnongl5 explants of immature inflorescence and immature embryos by particle bombardment. More than 100 transgenic plants were obtained under the selection of s-(2-aminoethyl)-L-cysteine (AEC). Confirmed transgenic plants of To and TI generation by PCR and PCR-Southern blotting analyses showed successful integration of wblrp gene into wheat genome. Analysis of transgenic plant lines of T2 by Northern dot-blotting showed good expression of wblrp gene in offspring seed. The content of free lysine in leaves, contents of bound lysine and total proteins in seeds of T2 transgenie wheat lines were determined and analyzed. Among 34 tested transgenic lines, levels of free lysine content in leaves of 9 transgenic lines are 2~3times higher than un-trans-formed wild-type cultivars. Among 17 analyzed transgenic lines, bound lysine content of 4 transgenic lines is more than 10% higher than that of wild-type cultivars. Our research suggests that introducing wblrp gene into wheat is an effective way to improve its nutrition quality.     

Transgene inheritance and quality improvement by expressing novel HMW glutenin subunit （HMW-GS）genes in winter wheat

The expression vector pBPC30, which carries the high molecular weight glutenin subunit (HMW-GS) 1Dx5 and 1Dy10 genes, was transferred into hexaploid winter wheat cv. Jinghua No. 1, Jing411 and Jingdong No. 6 explants of immature embryos and immature inflorescence by particle bombardment. A large number of resistant transgenic plants were obtained under the selection of herbicide bialaphos or phosphinothricin (PPT). Confirmed transgenic plants of To generation showed successful integration of HMW-GS genes and bar gene into the wheat genome. T1 generation of transgenic plants can resist 20--150 mg/L PPT.Protein analysis of T2 seed by SDS-PAGE showed that HMW-GS 1Dx5 and 1DylO genes were well expressed in offspring seed of transgenic lines by co-expression with or substitution of endogenous 1Dx2 or 1DylO. In one transgenic line, TG3-74, a new protein band between endogenous protein subunits 7 and 8 (marked as 8*) of glutenin appeared,but endogenous subunit 8 (encoded by 1By8 gene) was absent. Analysis of gluten rheological quality on seed proteins of 102 T3 plants showed that the sedimentation value of 5 transgenic lines (44.2149.0 mL) was remarkably improved,59.6%---64.3% higher than that of wild type Jinghua No. 1 and Jingdong No. 6, similar to bread wheat Cheyenne (48.0 mL). Analysis of dough rheological properties of transgenic lines showed that the dough stable time of 5 transgenic lines range from 16 to 30 min, whereas the dough stable time of wild type was only between 3--7 min. Our research suggests that introducing novel HMW-GS genes into wheat is an efficient way to improve its bread-making quality.     

小麦根尖细胞分化过程中木质素合成及其相关酶的活性变化

小麦（Triticumaestivum）根尖细胞分化过程中，苯丙氨酸解氨酶[PAL．EC4．3．1．5]和对香豆酸辅酶A联结酶[4CL，EC6．2．1．12]的活性从分生区至成熟区逐渐增加．PAL活性在分生区细胞中为0.4CL活性近似为0．在成熟区细胞中PAL和4CL活性均增加到最大．木质素的含量变化与PAL和4CL活性存在着平行性，同样在分生区细胞中木质素含量很低，到伸长区稍许增加，至成熟区增加最多．PAL和4CL是木质素合成的开始步骤和关键酶．木质素主要在管状分子和细胞壁次生加厚时沉积，是细胞分化的重要标志之一．     

小麦与高冰草体细胞杂种F5代麦谷蛋白及SDS沉降值分析

通过对普通小麦与高冰草体细胞杂种F5代 175个株系的麦谷蛋白及SDS沉降值分析 ,发现杂种F5代有 10种不同的麦谷蛋白组成 ,并出现了 1Ax1,1Ax2 ,1Bx13,1By16 ,1By8,1Dx5等 6种不存在于亲本小麦中的高分子量麦谷蛋白亚基及 1Bx13 1By16 ,1Bx7 1By8,1Dx5 1Dy12等 3种新亚基组合 ,部分杂种中出现了高冰草的麦谷蛋白特征谱带 ;杂种株系的SDS沉降值表现出较大的差异 ,其中一些杂种的SDS沉降值明显高于亲本普通小麦 .结果表明 ,通过体细胞杂交有可能将野生禾草的优良性状引入普通小麦 ,创造出多种不同组成及组合的新种质 ,为小麦品质育种开辟新途径     

Molecular mapping of QTLs for root response to phosphorus deficiency at seedling stage in wheat (Triticum aestivum L.)

Phosphorus (P) deficiency in the soil is one of the major abiotic stresses that limit plant growth and crop productivity throughout the world. Development of cultivars with improved P-deficiency tolerance is an efficient strategy for sustainable agriculture. Plant roots play an important role in crop growth and development, especially in nutrient uptake and improvement of P-efficiency. Mapping quantitative trait loci (QTLs) for root traits and their response to low P stress at seedling stage will facilitate the development of P-efficient wheat cultivars. In this study, 30 QTLs (LOD>2.0) were mapped for the three root traits, such as root length, root number and root dry matter under different P supply conditions and their response to P-stress. These QTLs were distributed on 14 chromosomes, with each of the 5 QTLs explaining more than 10% phenotype variance. Analyses showed that root traits and their response to P-deficiency were controlled by different QTLs. In addition, alleles with positive effects were separated on both parents, and wheat cultivars with improved P-efficiency could be developed by accumulating these positive effect alleles together.     

Molecular mapping of QTLs for root response to phosphorus deficiency at seedling stage in wheat (Triticum aestivum L.)

Phosphorus (P) deficiency in the soil is one of the major abiotic stresses that limit plant growth and crop productivity throughout the world. Development of cultivars with improved P-deficiency tolerance is an efficient strategy for sustainable agriculture. Plant roots play an important role in crop growth and development, especially in nutrient uptake and improvement of P-efficiency. Mapping quantitative trait loci (QTLs) for root traits and their response to low P stress at seedling stage will facilitate the development of P-efficient wheat cultivars. In this study, 30 QTLs (LOD>2.0) were mapped for the three root traits, such as root length, root number and root dry matter under different P supply conditions and their response to P-stress. These QTLs were distributed on 14 chromosomes, with each of the 5 QTLs explaining more than 10% phenotype variance. Analyses showed that root traits and their response to P-deficiency were controlled by different QTLs. In addition, alleles with positive effects were separated on both parents, and wheat cultivars with improved P-efficiency could be developed by accumulating these positive effect alleles together.