缺失不同Wx蛋白对普通小麦直链淀粉含量及淀粉特性的影响

为了明确普通小麦缺失不同W x蛋白对直链淀粉含量的影响以及部分糯小麦品系的淀粉特性,采用单向改良SDS-PAGE方法对1个非糯×糯杂交组合F2分离群体的196个单籽粒进行了W x蛋白筛选,测定了这批籽粒的直链淀粉含量,同时测定了1个部分糯小麦品系(缺失W x-B 1和W x-D 1)和2个正常型小麦品系粗面粉的直链淀粉含量、膨胀势和RVA粘度。结果表明,缺失1对W x蛋白的直链淀粉含量比正常型降低3.29~7.15个百分点,缺失2对W x蛋白的比正常型降低9.45~13.82个百分点,缺失3对W x蛋白的直链淀粉含量几乎为0;缺失W x-B 1和W x-D 1的部分糯小麦品系粗面粉的直链淀粉含量比正常型降低5.62~7.49个百分点,膨胀势则增加4.51~4.72,RVA高峰粘度显著高于正常型。     

糯性普通小麦的产生及其淀粉特性研究

以江苏白火麦（缺失Wx-Dl)和关东107（缺失Wx-Al和Wx-Bl）为亲本配制杂交组合，采用花粉和籽粒剖面染色、蛋白质电泳进行筛选和鉴定，人工创造得到自然界不存在的糯性小麦，并对其直链淀粉含量及淀粉品质性状进行研究。结果表明，所得到的两个糯性小麦吕系直链淀粉含量很低（小于1％），其糊化特性、膨胀势特性亦与普通小麦品种不同；RVA高峰粘度明显低于其亲本，其高峰粘度出现较快，而且反弹值不明显；其淀粉膨胀能力远大于亲本。     

青海高原春小麦糯性新品系的筛选及其直链淀粉含量

为了培育适合青海高原种植的春小麦糯性新品系,利用DNA分子标记技术检测了80株青春533×糯麦1号F2代材料的Wx基因缺失情况,同时测定了不同Wx基因缺失类型F2代材料的小麦籽粒直链淀粉含量。结果表明,在80株F2代分离群体材料中,单缺失WxA1或WxB1或WxD1基因的材料分别为8份、11份、9份;同时缺失WxA1和WxD1基因的材料为10份,同时缺失WxB1和WxD1基因的材料为12份,同时缺失WxA1和WxB1基因的材料为9份;WxA1、WxB1和WxD1基因全部缺失的材料为8份。Wx基因的缺失数量与直链淀粉含量的高低有密切关系,缺失1个Wx基因（部分糯小麦）,直链淀粉含量比对照（青春533）降低5.28%~11.35%;缺失2个Wx基因（部分糯小麦）,直链淀粉含量比对照降低10.73%~19.81%;缺失3个基因（糯小麦）的直链淀粉含量为0.97%,比对照降低30.53%。高原春小麦与糯性小麦杂交的F2代直链淀粉含量下降幅度要比前人所研究的材料下降幅度大,并且WxB1单缺失引起直链淀粉含量下降（11.35%）比WxA1和WxD1双缺失所引起的下降幅度要大（10.73%）。     

硬粒小麦缺失4A蜡质蛋白对直链淀粉含量及淀粉品质特性的影响

为了明确硬粒小麦缺失不同Wx蛋白对直链淀粉含量的效应和Wx-B1 缺失型(缺失4A蜡质蛋白)的淀粉特性,利用SDS-PAGE电泳分析技术对1个硬粒小麦F2分离群体(来源于以硬粒小麦品系B413Wx-B1缺失型为母本、PI435045Wx-A1缺失型为父本的杂交组合)的102个单籽粒进行了Wx蛋白的筛选,并测定了其中72个单籽粒(其中Wx-B1 缺失型21粒,Wx-A1 缺失型10粒,正常型41粒)的直链淀粉含量;同时测定了11个Wx-B1 缺失型和7个正常型硬粒小麦品系面粉的直链淀粉含量、膨胀势和RVA黏度.结果表明,硬粒小麦2对Wx基因的分离符合9∶3∶3∶1的分离模式,Wx-B1 缺失型籽粒的直链淀粉含量比正常型低4.78%.Wx-B1 缺失型的面粉直链淀粉含量比正常型低5.76%,RVA高峰黏度和膨胀势比正常型分别高116.02 RVU和3.69 g/g.相关分析表明,直链淀粉含量与RVA高峰黏度和膨胀势均呈极显著负相关.     

硬粒小麦若干淀粉性状研究

为了解硬粒小麦品种不同磨粉样品和不同类型间的淀粉品质特性,测定了2个硬粒小麦品种4种不同磨粉样品的膨胀势和5个不同类型品种的膨胀势和直链淀粉含量。结果表明,2个硬粒小麦品种不同磨粉样品的膨胀势均以淀粉最高;缺失4A型和7A型的硬粒小麦品种具有膨胀势高、直链淀粉含量低的特性。文中还对我国硬粒小麦品质改良作了讨论。     

小麦胚乳Wx蛋白缺失对淀粉含量和淀粉特性的影响

为给面条小麦亲本材料的筛选提供可靠依据，用SDS-PAGE和STS-PCR结合的方法鉴定了24个品种的Wx蛋白亚基组成，测定了这些品种的淀粉含量、膨胀势和RVA参数。结果表明，与正常材料相比，Wx蛋白亚基缺失材料的胚乳中直链淀粉含量减少，支链淀粉和总淀粉含量变化不明显，Wx蛋白亚基缺失的数目越多，直链淀粉含量减少得就越多，糯麦的直链淀粉含量最少。在本研究参试材料特定遗传背景干扰的情况下，在Wx蛋白的三个亚基中Wx-A1蛋白亚基对直链淀粉含量影响最大。Wx蛋白亚基的缺失还使面粉的膨胀势、RVA参数的高峰粘度、崩解值增大，峰值时间延长，而使最终粘度、回生值和糊化温度降低，Wx蛋白亚基缺失的数目越多，这些特性变化的幅度越大。在缺失单个亚基的情况下，Wx-B1亚基的缺失使小麦粉的淀粉特性表现最好。相关分析表明，直链淀粉合成数量的减少是导致上述淀粉特性发生变化的主要原因。     

小麦Wx蛋白及主要淀粉性状与面条品质的关系

为了研究小麦Wx蛋白及淀粉主要性状与面条品质的关系，对26个小麦品种的Wx蛋白含量、直链淀粉含量、峰值粘度、膨胀势进行了测定，并探讨了其与面条品质的关系。结果表明．三种Wx蛋白亚基的含量与面条品质均呈显著负相关．相关系数分别为-0．598、-0．446和-0．451；直链淀粉含量与面条品质呈显著负相关，相关系数为-0．711；峰值粘度和膨胀势与面条品质呈显著正相关，相关系数分别为0．614和0．601。表明三种Wx蛋白亚基及直链淀粉含量、峰值粘度、膨胀势均与面条品质有密切关系，呈显著相关（正向或负向）。     

玉米胚乳突变基因ae1和du1的遗传效应

利用玉米ae1和du1隐性纯和突变自交系与普通玉米自交系48-2的杂交F1、F2代子粒为研究材料,通过单粒法测定子粒的直链淀粉含量和重量,用于分析玉米胚乳突变基因ae1和du1的遗传效应.结果表明:F2代中具有ae1或者du1纯和突变的子粒表皮皱缩,重量明显下降,直链淀粉含量显著提高.在ae1与du1的杂交后代中,子粒的单粒重和直链淀粉含量没有显著变化,表明伽ae1与du1双突变并不能导致直链淀粉含量增加.单突变的ae1和du1群体内各子粒间的直链淀粉含量和重量差异较大,说明遗传背景中存在影响直链淀粉含量的修饰基因,表明在选育高直链淀粉玉米品系时,应当重视遗传背景的选择和修饰基因的累加.采用单粒法技术对分离后代进行直链淀粉含量和重量选择,有利于积累高直链淀粉修饰基因,是选育子粒饱满、高粒重的高直链淀粉玉米自交系的有效方法.     

不同直链淀粉含量小麦淀粉理化性质与消化特性研究

为深入理解小麦直链淀粉含量与淀粉理化性质及消化特性之间的关系,以4份直链淀粉含量差异较大的小麦品种为材料,分析了其淀粉理化性质以及消化特性方面的差异。结果表明,随着直链淀粉含量的增加,回生值呈增加趋势;在体外消化前期,4个小麦品种的淀粉消化速率差异显著,西农836最慢,陕糯1号最快。这种差异与直链淀粉含量及回生值密切相关,说明直链淀粉比支链淀粉更易于回生,糊化后的冷却过程中更容易发生分子间部分重排和再结晶,重新组装成有序的聚集体,导致供试材料之间快速消化淀粉含量及总体消化程度不同。直链淀粉含量高的品种具有更多的B型小淀粉粒,但是大量B型小淀粉粒的存在并没有导致淀粉消化速率以及淀粉总体消化程度的提高,说明淀粉充分糊化后,粒度的差异并不改变淀粉消化特性。     

缺失不同Wx蛋白对小麦籽粒直链淀粉合成及淀粉特性的影响

以缺失不同Wx蛋白小麦为试验材料,研究缺失不同Wx蛋白对小麦籽粒直链淀粉合成及淀粉特性的影响。试验结果表明,缺失不同Wx蛋白对小麦籽粒直链淀粉含量、积累量和积累速率、束缚态淀粉合成酶基因（GBSSI）基因相对表达量以及束缚态淀粉合成酶（GBSS）活性的影响顺序表现为：缺ABD型>缺AB型>缺B型>缺D型>缺A型>正常型;对淀粉最终粘度、反弹值以及糊化温度影响的表现顺序与其一致;对淀粉峰值粘度、低谷粘度、稀懈值以及膨胀势影响的表现顺序与此相反。相关分析表明,直链淀粉积累速率峰值、GBSSI相对表达量最大值以及GBSS活性峰值三者之间相互呈极显著正相关。说明GBSSI基因可能通过编码GBSS酶,从而控制小麦籽粒中直链淀粉的合成。     

Mineral composition of some traditional Mexican teas

Teas of plant origin traditionally consumed by the Mountain Pima of Chihuahua, Mexico, were analyzed for mineral nutritional content. Fe, Cu, Zn, Ca, and Mg composition was determined for native teas made from shoots ofTagetes lucida, T. filifolia, Elytraria imbricata, andHolodiscus dumosus, and from root xylem ofCeanothus depressus andPhaseolus ritensis. Native uses of these teas are also described.     

Comparative Assessment of the Efficacy of Various Nitrogen Fertilizers

Summary

The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices.     

Studies on natural repellents against potato tuber moth (Phthorimaea operculella Zeller) in country stores

Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong (1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage, sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over 45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield of a subsequent crop.     

Redox Status and Neuro Inflammation Indexes in Cerebellum and Motor Cortex of Wistar Rats Supplemented with Natural Sources of Omega-3 Fatty Acids and Astaxanthin: Fish Oil,Krill Oil,and Algal Biomass

Health authorities worldwide have consistently recommended the regular consumption of marine fishes and seafood to preserve memory, sustain cognitive functions, and prevent neurodegenerative processes in humans. Shrimp, crabs, lobster, and salmon are of particular interest in the human diet due to their substantial provision of omega-3 fatty acids (n-3/PUFAs) and the antioxidant carotenoid astaxanthin (ASTA). However, the optimal ratio between these nutraceuticals in natural sources is apparently the key factor for maximum protection against most neuro-motor disorders. Therefore, we aimed here to investigate the effects of a long-term supplementation with (n-3)/PUFAs-rich fish oil, ASTA-rich algal biomass, the combination of them, or krill oil (a natural combination of both nutrients) on baseline redox balance and neuro-inflammation indexes in cerebellum and motor cortex of Wistar rats. Significant changes in redox metabolism were only observed upon ASTA supplementation, which reinforce its antioxidant properties with a putative mitochondrial-centered action in rat brain. Krill oil imposed mild astrocyte activation in motor cortex of Wistar rats, although no redox or inflammatory index was concomitantly altered. In summary, there is no experimental evidence that krill oil, fish oil, oralgal biomass (minor variation), drastically change the baseline oxidative conditions or the neuro-inflammatory scenario in neuromotor-associated rat brain regions.     

Potential of dry fractionation of wheat bran for the development of food ingredients,part II: Electrostatic separation of particles

Wheat bran is a composite material made of several layers, such as pericarp, testa and aleurone. It could be fractionated into purified fractions, which might either be used as food ingredients, or serve as a starting material for extraction of bioactive compounds. The aim of this work was to evaluate the potential of using electrostatic separation as a way to obtain purified fractions from wheat bran. Ultrafine-ground bran obtained either by cryogenic grinding or by grinding at ambient temperature was used as starting material. The ultrafine bran was then charged by tribo-electrification and introduced in a chamber containing two high voltage electrodes, where bran particles were separated depending on their acquired charge, allowing positively and negatively charged fractions to be collected separately. The particle size distribution, microstructure and biochemical composition of the obtained fractions were studied. The charge of the particles was influenced by their biochemical composition: particles rich in highly branched and cross-linked arabinoxylans (pericarp) were separated from particles rich in β-glucan, ferulic acid and para-coumaric acid (aleurone cell walls). The testa and the intracellular compounds from aleurone were not highly charged, neither positively nor negatively. The most positively charged fraction represented 34% of the initial bran, and contained 62% of the ferulic acid present in the initial bran. The yield of the separation process was good (5.4% loss), and could be further increased.     

In vitro antimicrobial activity of different accessions ofSolanum commersonii Dun. from Uruguay

Summary The in vitro antimicrobial activity of extracts from accessions ofSolanum commersonii Dun. collected in the south of Uruguay was investigated against five microorganisms including the pathogenRalstonia solanacearum. A total of 30 extracts corresponding to organic and aqueous extracts were studied. Interestingly, most of the positive results for growth inhibition were againstR. solanacearum. The extracts were also analyzed for the presence of glycoalkaloids and lectins. Six of the ten aqueous extracts showed lectin presence and a wide variation in the type and amounts of glycoalkaloids, was found. Results indicate that there is no clear relationship between the antimicrobial activity against the five microorganisms screened and the presence or amounts of lectins and glycoalkaloids, traditionally regarded as possible antimicrobial metabolites in theSolanum genus, which indicates the presence of as yet unidentified antimicrobial compounds.     

Novel food and non-food uses for sorghum and millets

Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.     

<Emphasis Type="Italic">Pulque</Emphasis>, An Alcoholic Drink from Rural Mexico,Contains Phytase. Its <Emphasis Type="Italic">in vitro</Emphasis> Effects on Corn Tortilla

Pulque is made by fermenting the agave sap or aguamiel of Agave atrovirens with a whole array of microorganisms present in the environment including several lactic acid bacteria and yeasts such as Saccharomyces cerevisiae. Ascorbic acid was determined in pulque and aguamiel, respectively. Phytase activity in lees, liquid and freeze-dried pulque was assayed by measuring the appearance of phosphate from phytate by a colorimetric method likewise phosphate from phytate present in fresh corn tortilla was measured after in vitro incubation with pulque. Iron, zinc, calcium, magnesium and selenium contents were measured in pulque and corn tortilla as well as in nixtamalized corn flour (NCF), the latter is used to make instant tortilla, since corn provides most of the energy as well as most of the phytate in the Mexican rural diet. Pulque showed phytase activity but much less ascorbic acid and iron than previously reported; additionally, phytase in pulque hydrolyzed most of phytate’s corn tortilla. Lees, which is mostly made of pulque’s microbiota, significantly accumulated iron and zinc but no selenium. NCF was fortified with iron by the manufacturers but poorly blended. There were significant differences on selenium content between tortillas samples, apparently some soils in central Mexico are selenium deficient. Moderate pulque intake appears to increase the bioavailability of iron and zinc bound by phytate in corn.