氮离子注入对同源四倍体水稻成熟胚组织培养体系的影响

选择3份同源四倍体水稻为材料,研究了氮离子注入对其成熟胚诱导愈伤组织和分化成苗的影响。结果显示,低剂量范围(1.0×1016~2.0×1016ions/cm2)的N 注入能明显提高愈伤组织诱导率;无论离子注入剂量大小,N 注入能明显改善愈伤组织的发育状态,抑制其褐化衰老的进程,提高愈伤组织的绿苗分化率。     

N+离子注入对同源四倍体水稻种子萌发的影响

以同源四倍体水稻IR36(4)为材料,研究了不同剂量的低能(25 keV)N 离子注入对种子萌发的效应,结果表明,低能N 离子注入对种子的萌发有一定影响。在低剂量(2×1016N /cm2)时,N 注入对IR36(4)种子萌发起到刺激作用,种子的存活率、吸水率、幼苗淀粉酶活性相对CK都有所提高;当注入剂量在2×1016~10×1016N /cm2范围内,N 注入对IR36(4)种子萌发起抑制作用,表现为种子存活率显著降低、淀粉酶活性下降、膜透性增大。     

金钱树四倍体的诱导与鉴定

以金钱树块茎为材料,采用秋水仙素溶液处理不定芽生长点,研究秋水仙素浓度和处理时间的诱变效果。结果表明：0.1%的秋水仙素溶液浸泡处理块茎的不定芽48 h效果最好,其诱导率为30%。通过流式细胞仪对金钱树植株DNA相对含量的测定,鉴别出四倍体和嵌合体。四倍体植株与二倍体植株在叶厚、保卫细胞大小、气孔密度等方面存在明显差异,其中气孔的形态及密度可作为鉴别四倍体、嵌合体和二倍体的重要性状。     

氮离子束注入和钴60伽玛辐射对大豆产量性状和品质的影响

分别以3种剂量的N离子束注入(4×1016,6×1016和8×1016 N+ ·cm-2)和3种剂量的60C o-γ射线辐射(100,150和200 Gy)处理4份大豆干种子,在相同种植条件下对其M6代产量性状和品质进行研究,比较2种处理方法对大豆产量性状及品质的诱变效应.结果表明:与对照相比,新大豆3号4×1016N+·cm-2离子束注入处理单株荚数显著增加,6×1016N+ ·cm-2离子束注入处理产量极显著增加;合99-756 8×1016 N+ ·cm-2离子束注入处理单株粒数和单株粒重显著减少,6×1016N+ ·cm-2离子束注入处理百粒重显著减少,100 Gy60 Co-γ射线辐射处理蛋白质含量显著降低,100,150和200 Gy60 Co-γ射线辐射使脂肪含量显著提高;新大豆8号4×1016和8×1016 N+ ·cm-2离子束注入、100和200 Gy60Co-γ射线辐射处理单株粒重显著减少,4×1016和6×1016 N+ ·cm-2离子束注入及200 Gy60Co-γ射线辐射处理产量极显著或显著增加;N离子束注入和60Co-γ辐射对石大豆2号产量、各产量构成因素及品质的影响差异不显著.因此,诱变育种目标应根据材料的敏感性、诱变方法和剂量综合确定.     

基于DH系的种质基础和秋水仙素浓度对玉米单倍体加倍效果的研究

以先玉335为母本、高频孤雌生殖诱导系G5为父本杂交诱导产生的单倍体为实验材料,研究秋水仙素浸芽加倍处理玉米单倍体的最佳浓度和时间。结果表明,秋水仙素浓度为0.7 mg/m L、浸芽8 h处理下的玉米单倍体加倍率最高,高达14.4%;秋水仙素浓度为0.8 mg/m L、浸芽8 h处理下的单倍体加倍率次之,为12.1%。以自交系PHB1M、PH4CV、PH6WC、PHGJ4和DH系Z2、Z8为亲本组配的PHB1M×PH4CV、PHB1M×Z2、PH4CV×DZ2、PH6WC×PHGJ4、PH6WC×Z8、PHGJ4×Z8组合为母本,以G5为父本,研究玉米DH系对杂交后代加倍率的影响,结果表明,PH4CV×Z2(26.2%)、PHB1M×Z2(25.8%)、PHGJ4×Z8(23.3%)和PH6WC×Z8(21.3%)的单倍体加倍率显著高于PHB1M×PH4CV(13.5%)和PH6WC×PHGJ4(8.4%),以DH系为亲本组配选系基础材料可显著提高玉米杂交组合的单倍体加倍率。     

君子兰二倍体与四倍体叶片性状的比较研究

[目的]观察秋水仙素离体诱导后的四倍体君子兰形态性状是否发生改变,为其多倍体诱导及鉴定提供更多依据。[方法]以移栽后的2年生君子兰二倍体和秋水仙素诱导获得的四倍体株系为材料,对不同倍性君子兰的叶片厚度、长度、宽度以及叶片下表皮气孔密度、大小、叶绿体数进行观察比较。[结果]君子兰加倍植株的性状稳定,四倍体君子兰叶片变厚、变短、变宽,且表面粗糙,生长缓慢;二倍体君子兰叶面光滑,叶薄,生长较快。此外,四倍体君子兰的气孔(40.5μm×12.3μm)和保卫细胞(59.9μm×21.9μm)明显变大,气孔密度(14.3个/mm²)变小。[结论]秋水仙素离体诱导君子兰所获得的四倍体植株性状稳定,叶片和气孔性状可以作为判断君子兰是否加倍的辅助指标。     

秋水仙素对猪屎豆的诱变及同源四倍体种质创制的研究

猪屎豆是重要的农业植物资源,在绿肥、饲用和药用等方面都有重要的开发潜力,然而目前关于猪屎豆的品种培育还处于空白,生产上缺乏优良品种导致生产性能参差不齐的问题突出,开展多倍体育种研究可为今后猪屎豆种质资源创新利用和培育新品种奠定材料基础。本研究以二倍体猪屎豆为实验材料,通过不同质量浓度秋水仙素和不同处理时间对猪屎豆露白种子进行多倍体诱导,探讨秋水仙素对二倍体猪屎豆的诱变效果,并利用流式细胞倍性检测和根尖染色体核型分析对诱变后代的倍性进行检测,进一步比较分析二倍体和同源四倍体的气孔和保卫细胞大小以及叶片和种子形态等特征变化。结果表明：与对照相比,秋水仙素处理抑制了猪屎豆种子胚根的生长和下胚轴的伸长,使种子胚轴发生诱变而缩短变粗。研究发现以100 mg/L的秋水仙素浓度浸泡12h时猪屎豆种子四倍体诱导率最高,为13.33%,总体效果最佳。与二倍体相比,同源四倍体植株叶片下表皮的气孔长度和宽度、保卫细胞长度和宽度显著增加而气孔密度显著降低;同源四倍体植株的叶片宽度和叶柄宽度显著增加,而叶片长度和叶柄长度显著缩短;同源四倍体植株的叶形指数显著减小。此外,同源四倍体植株所获种子较二倍体显著增大,种...     

离子束处理甜菜杂交种当代效应研究

培育和改良具有优质、高产的作物新品种是品种选育和资源利用的重要研究内容。本研究以甜菜杂交种为处理材料,用N+离子作为诱变源,用35kev的能量,分别以40次、60次脉冲,注入剂量4×1016/cm2、6×1016/cm2进行激发诱变,甜菜杂交种的产量、含糖率均有明显的提高,为甜菜杂交种处理获得当代效应提供了有益参考。     

药用万寿菊多倍体的诱导与特征分析

为获得四倍体药用万寿菊材料,采用秋水仙素对药用万寿菊‘内蒙1号’的种子进行多倍体诱导研究。以0.15%浓度的秋水仙素处理露白的万寿菊种子24 h,幼苗变异率较佳,可达到56%。幼苗定植于田间,初步筛选并标记形态变异植株,自花授粉后采收种子播种并观测子代形态指标,对形态变异明显的植株进行流式细胞仪检测,确定获得15株纯合四倍体。通过将四倍体与二倍体进行比较,四倍体植株茎粗、栅栏组织厚度、栅栏组织与海绵组织的比例和单朵花重量显著高于二倍体植株,四倍体植株总叶量、叶宽、叶长、叶长宽比、叶片气孔密度和单株花朵数量显著低于二倍体植株。获得的四倍体万寿菊植株单株花总重量比二倍体显著增加。     

秋水仙素处理后水稻种子内胚乳蛋白的差异性比较分析

经过秋水仙素对二倍体水稻品种圭630（2）处理后,其后代材料在蛋白质水平上表现出明显的差异性。染色体组的倍性水平对水稻种子内胚乳蛋白的表达量有明显的影响。经过秋水仙素处理后,在具有嵌合性特征的植株上大粒种子与原始亲本的种子在总蛋白含量上存在着明显的差异,大粒种子与小粒种子的差异也很明显。染色体组的多倍化对原始亲本的胚乳蛋白含量有明显的影响,由此所获得的同源四倍体水稻株系,其种子内的蛋白质含量比较多。SDS—PAGE分析结果表明,经过秋水仙素诱导后,试验材料的种子内蛋白质亚基的类型没有出现新的变异,而蛋白质亚基的表达量发生了明显的变化。     

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.     

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.     

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.     

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.     

<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.     

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.