花生白绢病温室接种技术的建立和苗期抗病性鉴定

为探索温室条件下适宜花生白绢病人工接种的技术体系,对花生白绢病人工接种技术进行了系统的研究。通过比较5种接种技术,发现带菌燕麦粒贴茎法和撒表土法的发病效果较好,可以作为花生白绢病温室抗性鉴定的接种方法,其中带菌燕麦粒撒表土法比贴茎法更易操作;不同量(1~5粒)的带菌燕麦粒撒表土法接种花生幼苗的病情指数差异不显著,但以接种4粒燕麦粒病害发展速度最快;15~35d苗龄的花生幼苗接种带菌燕麦粒后,病情指数差异不显著。本研究建立的接种技术白绢病发病快,发病率达到100%,最大病情指数为89.2。利用该技术在温室内对19个花生品种/系进行了苗期白绢病抗病性鉴定,大部分材料中感或高感,仅中花16表现相对抗性。     

小麦粒形QTL元分析及候选基因预测

粒形是影响小麦籽粒产量和品质的重要参数,是由多基因控制的复杂数量性状。为发掘控制小麦粒形相关的真实主效数量性状位点(quantitative trait loci, QTL),本研究利用BioMercator 4.2软件,以小麦高密度分子标记遗传图谱为参考图谱,对来自不同遗传作图群体的113个控制小麦粒长的QTL和86个控制粒宽的QTL进行图谱整合、映射以及QTL元分析。通过建立QTL一致性图谱,获得18个控制小麦粒长和8个控制粒宽的一致性QTL(meta quantitative trait loci, MQTL)位点,置信区间最小可达到0.57 cM,主要分布在2B、2D、3A、3B、4B、5A、5B和7D染色体上。在5A染色体Xgwm293～Xgwm304和Xgpw2120～Xgpw2273a标记区间内,预测到7个与小麦粒长和粒宽相关的候选基因。本研究为小麦粒形QTL精细定位以及分子标记辅助选择育种提供理论依据。     

大豆抗食心虫性的遗传及抗虫育种方法的研究——Ⅰ.人工接虫条件下F_2代的抗虫性

在网室内用人工接虫的方法对2个抗虫×抗虫,和7个抗虫×感虫大豆杂交组合的F_2群体,及抗虫和感虫亲本,进行了抗性鉴定。根据抗、感亲本的虫食粒率和受害荚率,将F_2代植株的抗虫性分为5级。结果表明,F_2代的抗虫性呈非对称分布,分布高峰的位置因组合而异,且不具有数量性状特有的中心对称分布特征。2个抗×抗组合的F_2代,均分离出一定比例的感虫或高感个体,暗示父母本可能分别带有不同的抗虫基因。同一抗虫亲本与不同的农艺亲本杂交后,F_2代的抗虫性分离比例有较大的差异。抗×抗和抗×感组合的F_2代,都可以分离出较大比例的抗虫单株,超亲现象很普遍,因此,在适宜的接种强度下,抗食心虫性的选择,可能比选择其它数量性状更易奏效。     

转基因抗虫性水稻恢复系选育及特性分析

将优质抗稻瘟病水稻恢复系成恢177与转基因水稻Bt明恢63杂交并回交1次,采用PCR分析、试纸条检测、室内和田间人工接虫鉴定抗虫性,并结合系谱法选择农艺性状,病圃接种鉴定稻瘟病抗性,育成具转基因抗虫性的水稻新恢复系Bt5198。采用离体茎秆法接种二化螟卵块,新恢复系Bt5198和Bt明恢63的幼虫死亡率均为100%。在田间人工接虫条件下,该恢复系对二化螟和三化螟均表现高抗,与4个不育系配制的杂种F1仍保持良好的抗虫性,且杂种优势明显。两年稻瘟病抗性鉴定结果表明,新恢复系Bt5198的叶瘟和颈瘟抗性水平与成恢177相当,明显优于Bt明恢63。Bt5198的种子发芽率和花粉量与成恢177相当,Bt基因导入水稻恢复系不会对种子生活力和制种产量造成显著影响。在无选择标记基因的转基因后代中,结合利用试纸条检测和室内、田间人工接虫鉴定是筛选Bt基因抗虫性的有效方法。     

基于卷积神经网络的水稻纹枯病图像识别

【目的】水稻纹枯病是影响水稻生产的三大病害之一。研究卷积神经网络对水稻纹枯病的自动识别,弥补人工识别的不足,对预防和准确识别水稻蚊枯病类型有着重要意义。【方法】以卷积神经网络进行水稻纹枯病识别,并与基于支持向量机的识别方法进行对比。【结果】卷积神经网络识别率达到97%,优于支持向量机的95%。【结论】卷积神经网络运用于水稻纹枯病识别是可行的,弥补了人工识别的不足。此算法训练的模型有着较好的识别性能。     

不同褐飞虱寄主种群类酵母共生菌形态和数量的比较

 对分别在不同水稻品种TN1（感虫品种）、Mudgo（含Bph1抗虫基因）、ASD7（含bph2抗虫基因）上连续饲养了117代以上的3个褐飞虱寄主种群（分别称为TN1种群、Mudgo种群、ASD7种群）体内类酵母共生菌的形态和数量进行了比较。各褐飞虱种群类酵母共生菌的长和宽差异显著,且ASD7种群＞TN1种群＞Mudgo种群;长宽比无明显差异。种群间类酵母共生菌数量的差异因试虫性别而异,不同种群的褐飞虱雌虫含菌量无明显差异,雄虫则表现出TN1种群＞ASD7种群＞Mudgo种群的趋势,其中TN1种群与后两者差异显著,后两者间无显著差异。各褐飞虱种群转移到不同水稻品种上饲养1代,雌虫含菌量变化大多不明显,但雄虫较明显。感虫品种TN1上雄虫转移到两个抗性品种Mudgo和ASD7上饲养含菌量显著降低,抗虫品种上的雄虫转移到TN1上则含菌量显著增加,抗虫品种间的转移含菌量则没有明显变化。     

利用近红外吸收光谱对水稻种子活力的判别方法

为了实现对水稻种子活力的无损检测,采用近红外光谱分析技术,通过近红外光谱仪采集单粒水稻种子的透射光,比较不同的预处理方法的偏最小二乘判别分析模型(Partial Least-Squares Discriminant Analysis,PLS-DA),选择归一化+二阶差分+正交信号校正(Orthogonal Signal Correction,OSC)的预处理方法对透射光谱进行预处理,得到的日本晴种子的建模集识别率为94.44%,检验集识别率为91.67%;9311种子的建模集识别率为98.61%,检验集识别率为91.67%。表明该光学系统和数据处理模型对水稻种子的活力辨别具有较高的准确率。     

茶尺蠖病原真菌的分离鉴定及其特性

茶尺蠖(Ectropis oblique Prout)是华东茶区的主要害虫,近年来安徽茶园中的茶尺蠖普遍被真菌感染,经分离鉴定为圆孢虫疫霉(Erynia radieans(Brefeld)Humber et al)。它在该地区的大面积流行,有效地抑制了茶尺蠖的种群数量。本文对真菌的形态特征、精细结构、生物学特性、人工培养和引起流行病的因子进行了分析讨论。     

基于小波矩的大豆外观品质特征提取方法的研究

应用机器视觉技术对大豆的外观品质进行检测成为近年来的研究热点,大豆的外观特征提取是检测的重要内容之一。为提高大豆样本的识别率,减少噪声对特征提取造成的污染,提出了一种基于小波矩的大豆外观品质特征提取方法。该方法对大豆样本图像进行基于小波变换的不变矩特征提取,有效地解决了由于大豆本身存在的大小不同、移动等造成的特征不明的问题。试验证明:此方法不仅能够精确地描述大豆外观品质特征而且对噪声不敏感,此方法识别精度高,正确识别率达到99%。     

中华稻蝗在辽宁中部地区的发生及防治

针对中华稻蝗在辽宁中部地区发生面积逐渐扩大的实际情况,用人工饲养和田间观察的方法对该虫的发生规律、生活习性、危害程度及对水稻产量因素的影响进行了研究,提出了化学防治的最佳时间和有效的药剂。     

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.     

Pharmacokinetics of Marine-Derived Drugs

Marine organisms represent an excellent source of innovative compounds that have the potential for the development of new drugs. The pharmacokinetics of marine drugs has attracted increasing interest in recent decades due to its effective and potential contribution to the selection of rational dosage recommendations and the optimal use of the therapeutic arsenal. In general, pharmacokinetics studies how drugs change after administration via the processes of absorption, distribution, metabolism, and excretion (ADME). This review provides a summary of the pharmacokinetics studies of marine-derived active compounds, with a particular focus on their ADME. The pharmacokinetics of compounds derived from algae, crustaceans, sea cucumber, fungus, sea urchins, sponges, mollusks, tunicate, and bryozoan is discussed, and the pharmacokinetics data in human experiments are analyzed. In-depth characterization using pharmacokinetics is useful for obtaining information for understanding the molecular basis of pharmacological activity, for correct doses and treatment schemes selection, and for more effective drug application. Thus, an increase in pharmacokinetic research on marine-derived compounds is expected in the near future.     

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.