Effect of incorporated green manure crops on subsequent oat production in an acid,infertile silt loam

A field-size experiment was initiated in 1982 on an acid, low fertility Springhill silt loam to determine the effect of five unfertilized green manure crops (alsike clover, sweet clover, single- and double-cut red clover, and buckwheat) on subsequent oat production and soil fertility. The field was limed in 1982 and green manures were seeded (without fertilizer) in spring, 1983 in 1400 m² strips randomly assigned within three treatment blocks. Plant tissue samples were taken from different locations in each plot in the fall of 1983 and all crops were incorporated. In 1984 the field was separated into an upper and lower section and each section received three rates of NPK fertilizer (0; 30-36-36; 60-72-72 kg ha^-1) spread across the previous strips. Gary oats were seeded and at harvest were divided into grain and straw. The results indicated significant effects of field sample location, green manure type and fertilizer level on oat yields. Buckwheat significantly reduced oat production compared to the four clovers, while the highest fertilizer rate improved oat yields compared with the other levels of fertilizers. Elemental analysis of the green manure crops and soil fertility was compared with data of the same crops grown in more fertile, neutral soils.     

Structural difference between polymerized and non-polymerized fragment X, obtained by plasmin digest of fibrinogen

Fragment X (LMrFX) was obtained as low molecular weight preparations from a late stage 2 plasmin digest of human fibrinogen. The thrombin-treated LMrFX preparations, which resulted in impaired polymerization, were further subfractionated into polymerized and non-polymerized components. The fractions were examined by SDS-PAGE and immunochemical methods. In polymerized fractions, more peptide bands were observed on SDS-PAGE in the reduced state than in non-polymerized fractions. Both fractions contained a similar number of internal cleavages in the A, Bβ and γ chains, which are linked by disulfide bonds. Thus, the partial deficiencies in polymerization sites of the carboxy terminal region of the γ chain and the amino terminal portions of the Bβ chain, as well as internal cleavage, were considered to participate in the impairment of the thrombin-induced polymerization of LMrFX.     

苦荞过敏蛋白TB22的原核表达及纯化

为了确定苦荞主要过敏原蛋白TB22的抗原决定簇,揭示其致敏机制,为以后的分子改造及育种改良打下基础,需要在体外微生物体系中获得大量的纯化蛋白。以pQE31为表达载体,M15为表达菌株,使用IPTG诱导,在37℃获得了以包涵体形式存在的表达产物。经WesternBlotting检测,证明表达条带N端带有Histidinetag。使用8molL尿素初步纯化后,目的蛋白含量达到40%以上。进一步HitrapChelatingHP亲和纯化,表达蛋白的纯度达到90%以上。建立了适合重组TB22纯化的基本方法,得到了纯化的包涵体,为抗TB22抗体的制备及其抗原决定簇的研究奠定了基础。     

甜荞种质资源创新方法的研究

甜荞是异花授粉作物,自然界中的甜荞种质资源多存在生物学混杂现象。每份甜荞种质资源可以分化出若干份新的遗传资源类型,其遗传背景复杂。简化甜荞种质资源的遗传背景,准确描述新品种的亲子代关系和遗传背景一直是世界荞麦工作者面对的技术难题。甜荞种质资源的繁育需要采取隔离措施,实施过程中需要考虑甜荞花粉粒大小、甜荞授粉机制、访问昆虫种类以及种子量多少等。为解决上述问题,本研究建立了以隔离杂交圃、隔离单繁圃、隔离扩繁圃、隔离比较圃和田间试验圃的荞麦繁育新方法——"五圃法",以期开发出不同类型的新的荞麦资源,在育种中可针对性的配制强优势组合,为新品种选育提供种质材料。     

一个含有乳链菌肽抗性基因的乳酸乳球菌质粒pTS50的鉴定

在添加乳链菌肽、乳糖及溴甲酚紫的M1 7选择培养基上 ,从 1 97个新鲜牛奶样品中筛选到 3株乳链菌肽抗性菌株 ,PCR扩增证实它们都含有乳链菌肽抗性基因。菌种生理生化特性鉴定及特异性 1 6SrDNAPCR扩增产物的序列测定结果表明这 3株菌都属于乳酸乳球菌乳酸亚种。质粒转化实验发现乳酸乳球菌乳酸亚种TS 1 640中的乳链菌肽抗性基因位于一个约47kb的大质粒pTS50上。BamHI、EcoRI、HindⅢ、NcoI、PstⅠ酶切分析和Southern杂交 ,进一步将乳链菌肽抗性基因定位于pTS50的一个约 1 9kbEcoRI酶切片段中     

一种适用于质谱分析的简化胶内酶解方法

在常规方法的基础上,设计了一种适于质谱分析的简化胶内酶解方法。改进的步骤包括:(1)通过加大洗涤所用超纯水量、延长涡混时间来强化凝胶洗涤的环节;(2)加入酸化处理来提高胰蛋白酶的活性;(3)在预酶解时不加CaCl_2,减少了酶的自切作用;(4)省略了蛋白质样品脱盐、脱SDS的步骤;(5)直接吸取酶解液进行质谱分析。系统比较该简化酶解法和最新报道的一种酶解方法的质谱鉴定效果,简化法能有效减少酶解后肽段的损失,增加质谱数据库搜索的信息量,得到更可靠的蛋白质鉴定结果。     

荞麦属种质资源发芽种子过氧化物酶同工酶研究

用聚丙烯酰胺凝胶电泳对荞麦属9个种(含大粒组8个和小粒组1个)32个收集系栽培及野生荞麦种子的过氧化物酶同工酶进行了研究。结果表明:过氧化物酶同工酶酶带23条,不同物种的酶带数4到8条。其中,甜荞有7条带,而苦荞为4条。酶带分析及聚类分析表明:大粒组荞麦种的谱带与F.gracilipes等小粒组荞麦种间差异极大,甜荞和苦荞酶带分别与F.megaspartanium和F.pilus相似,并分别与F.megas-partanium和F.pilus聚类最近,支持F.megaspartanium和F.pilus可能分别是甜荞和苦荞祖先种的假说。     

恒定磁场对苦荞种子的生物学效应

本试验用不同剂量的恒定磁场处理苦荞种子,结果表明：适宜的磁场可有效地提高苦荞种子萌发期的发芽势、发芽率,降低种子浸出液的电导率。     

普通荞麦植株茎段快速繁殖技术的研究

以普通养麦（Fagopyrum esculentum Moench）植株带节茎段为外植体,用正交设计法研究不同激素处理对荞麦腋芽、丛生芽和根的诱导及分化过程的影响,建立了荞麦离体培养快速繁殖技术。极差分析表明,6-BA是诱导荞麦茎段腋芽和根发育的主要因素,TDZ是诱导丛生芽的关键因素。诱导荞麦茎段腋芽发育的最佳培养基为：MS0＋6-BA1．0mg／L＋NAA0．1mg／L,腋芽诱导率为67．9％。其中,以第二、三节位的腋芽诱导率较高,达80％以上。诱导荞麦茎段丛生芽发育的最佳培养基为：MS0＋6-BA4．0mg／L＋TDZ0．06mg／L,丛芽分化率为166．7％。诱导生根的最佳培养基为：1／2MS0＋6-BA1．0mg／L＋NAA1．0mg／L,生根率为82．8％。该组织培养技术的建立为养麦快速繁殖提供了新途径。     

外源水杨酸和茉莉酸对荞麦幼苗耐盐生理特性的效应

以盐敏感荞麦品种‘TQ-0808’幼苗为材料,采用100mmol·L^（-1）NaCl并添加不同浓度水杨酸（sA）和茉莉酸（JA）的处理方法,测定荞麦耐盐生理指标,确定外源SA和JA对荞麦耐盐生理特性的效应。结果表明,外源SA和JA均能明显降低盐胁迫下荞麦叶片质膜透性和丙二醛（MDA）含量,外源SA降低的幅度略高于JA,外源SA最适浓度为0．6mmol·L^（-1）外源SA和JA均能明显增加盐胁迫下荞麦叶片超氧化物歧化酶（SOD）和抗坏血酸过氧化物酶（APX）活性及叶片净光合速率,外源JA增加的幅度明显大于SA,外源JA最适浓度为40gmol·L^（-1）。外源sA和JA明显改善盐胁迫下荞麦的生理特性,对盐胁迫具有较好的缓解作用,说明通过适当浓度的外源SA和JA处理来提高荞麦耐盐性是可行的。