小麦叶鞘和节间生长过程的模拟研究

以5个不同株型小麦品种为供试材料,通过对冬小麦品种叶鞘和节间生长过程的连续观测和定量分析,构建了小麦叶鞘和节间生长过程的动态模拟模型。模型采用Logistic方程描述了叶鞘和节间的伸长动态;利用叶鞘与对应节间长度的比例关系模拟了不同节间的长度;利用节间粗与对应节间长的比例关系定量描述了不同节间的粗度。模型检验结果显示,不同叶鞘长、节间长和节间粗预测值的平均RMSE值分别为1.34、1.71和0.06 cm,表明本模型具有较好的预测性和可靠性。     

冬小麦麦穗生长过程的模拟研究

为了实现小麦麦穗生长过程的可视化表达，以不同氮肥处理条件下不同类型小麦品种的两年田间试验为基础，通过连续观测并记载不同处理条件下的小麦主茎和分蘖麦穗形态指标（包括穗长、穗宽和穗厚），综合分析了小麦麦穗形态指标随生育进程和环境条件的变化规律，并利用系统分析方法和动态建模技术，构建了冬小麦麦穗生长过程的动态模拟模型。结果表明，麦穗的伸长过程符合S型曲线，而不同蘖位麦穗的最终长度符合二次曲线，且在不同氮肥处理之间均差异明显；采用Logistic方程描述了麦穗长度的动态变化过程，用二次曲线和线性方程定量描述了穗形的动态变化过程，同时采用旗叶的SPAD值量化了氮素对麦穗生长特征的影响；并利用不同小麦品种的田间试验资料对所建模型进行了测试和检验。结果显示，不同时期麦穗穗长、穗宽和穗厚预测值的平均RMSE分别为0．28、0．05和0．04cm。表明模型具有较强的动态预测性和可靠性，从而为进一步建立虚拟小麦生长系统奠定了基础。     

不同蛋白质含量类型小麦的茎型指标分析

为给优质高产小麦的育种和栽培建立茎型指标体系,2002～2003年度和2003～2004年度分别以不同蛋白质含量类型的小麦品种(系)71个和94个为供试材料,测定了株高、各节间长度、籽粒蛋白质含量和产量,研究了不同蛋白质含量类型小麦的株高和各节间长度等茎部性状的差异及其与产量的关系.结果表明,高蛋白质含量类品种的株高、倒2节间长和倒3节间长显著大于低蛋白质含量类型品种;高蛋白高产类型小麦的适宜株高、穗下节间长、倒2节间长和倒3节间长分别为85～107 cm、27 cm 以上、23 cm左右和14 cm左右,在适宜范围内以各项值稍大较为理想;低蛋白质含量、高产类型的品种则分别为85 cm以下、30 cm 以下、18.5 cm左右和12 cm左右,在适宜范围内各项值以稍小较为理想.     

中国北方杂草稻深覆土条件下出苗动力源分析

 以盆栽的方式,采用不同的覆土深度,对中国北方杂草稻的出苗特性进行了研究,分析了杂草稻的出苗动力源。研究结果表明,在中国北方发现的部分杂草稻具有较强的中胚轴伸长特性和芽鞘节间伸长特性。在播种深度较浅时（3 cm）,杂草稻依赖于中胚轴的伸长顶土发芽;当覆土较深时（5 cm）,杂草稻中胚轴伸长特性更加明显,伸长长度加大,同时杂草稻的芽鞘节间也明显伸长,中胚轴和芽鞘节间的共同伸长为深覆土条件下杂草稻的出苗提供了动力基础。     

大麦植株干物质分配模型

为给建立大麦产量品质形成预测模型奠定基础,通过定量分析不同品种和氮肥处理大麦干物质分配和转移的变化过程,建立大麦植株干物质分配动态模型.模型采用Richards方程描述大麦干物质分配指数的动态变化,引入叶片潜在分配指数、茎鞘潜在分配指数、籽粒潜在分配指数3个品种遗传参数反映不同品种在器官间的干物质分配差异;采用两段Richards方程来描述大麦茎鞘在灌浆期前后的干物质分配动态,较好地解决了两段方程的衔接问题;运用氮素影响因子来校正不同氮素水平对大麦干物质分配的影响,引入潜在临界含氮量和潜在最小含氮量2个品种遗传参数来表达氮素对不同品种干物质分配影响的差异.利用不同品种、氮肥、播期和种植地域试验数据检验模型.结果表明,大麦干物质在叶片、茎鞘、穗和籽粒间分配模拟值与观测值的绝对预测误差为0.001～0.252 kg·m-4,RMSE为0.007～0.186 kg·m-2,精度良好.模型体现出较好的可靠性.     

拔节期光强对水稻基部节间长度的影响

基部节间过长是导致水稻倒伏的关键因素之一。光强对水稻茎秆基部节间长度有重要影响。本研究在拔节前1叶龄期(S_0)、第1节间伸长期(S_1)以及第2节间伸长期(S_2),采用遮阳网遮光的方法,设置3种不同光强:29%透光率(A)、67%透光率(B)和100%全光照(不遮光,C),研究不同节间伸长期光强对节间长度的影响。结果表明,在拔节前1叶龄期,基部第1、第2和第3节间长度在不同光强处理间均无显著差异;在第1节间伸长期和第2节间伸长期,随着光强的增加,正在伸长的节间显著缩短,但光强对其他伸长节间的长度无显著影响。回归分析表明,光强与正在伸长的基部节间长度呈显著负相关关系,而与其他伸长节间长度的相关性不显著。在第1节间伸长期,光强每增加1 000 Lum/ft~2,第1节间将缩短0.5 cm;而在第2节间伸长期,光强每增加1 000 Lum/ft~2,第2节间则缩短0.7 cm。上述结果表明,光强仅对正在伸长节间的长度产生显著影响,其中第2节间对光强的反应比第1节间更为敏感。在生产实践中可通过栽培调控提高群体透光率,避免基部节间过度伸长,从而提高水稻抗倒伏能力。     

不同产量水平小麦最适总茎数动态模型研究

为给小麦田间管理提供科学依据,以2000～2002年田间试验为基础,结合相关文献资料,借鉴R/WCSODS思路,建立了不同产量水平小麦最适总茎数动态模拟模型,利用济南与南京地区常年气象资料及相应品种参数等进行了检验.结果表明,在7 500 kg·ha-1产量时济麦19号和济麦20号在济南的最适总茎数动态模拟值与实测值的相关系数为0.9649～0.9690,差值标准误为154.2万～155.2万·ha-1,平均绝对误差为14.25万～127.5万·ha-1;在6 000 kg·ha-1产量时扬麦5号在南京的最适总茎数动态模拟值与实测值相关系数为0.9987,差值标准误为81.56万·ha-1,平均绝对误差为1.38万·ha-1.模拟值与实测值的相关系数均达显著或极显著水平.     

籼粳亚种间组合秆高的初步研究

对54个籼粳交组合及其亲本的分析表明,F1代秆高优势明显,表现为地上部伸长节间数增多和各节间伸长,特别是第二、三节间伸长,F1秆高与高、中亲值及其抽穗日数均呈极显著正相关,与单株粒数不存在显著的线性相关,F1具6个伸长节间,以第四、第六节间长度对秆高的直接影响大,第六节长度与每穗总粒数呈极显著正相关。但第1、2、3、4节间长度与每穗总粒数则是极显著或显著负相关。     

水稻出苗顶土动力源研究

在自然条件下,通过设计不同的出苗阻力（覆土深度2 cm、4 cm和6 cm）来测定中胚轴伸长潜力不同的水稻种质的出苗速度、成苗率和芽鞘节及中胚轴的长度,以分析影响水稻种子顶土出苗的动力源。结果表明,水稻种子的出苗动力主要来源于芽鞘节间和中胚轴的伸长。在不同阻力处理条件下,不同种质出苗动力差异较大,其中覆土2 cm的不同种质出苗率相差不明显,与室内发芽率结果比较接近,覆土4 cm和覆土6 cm的两个处理不同种质间出苗率差异明显,长胚轴种质出苗速度快,出苗率高,出苗率与室内发芽率相差不大;而短胚轴种质出苗速度慢,出苗率低,其中春江683的出苗率与室内发芽率相比分别下降了6.5和86.2个百分点。研究表明水稻中胚轴的伸长对覆土较深的种子顶土出苗起到关键作用,长胚轴种质顶土出苗动力来自于芽鞘节与中胚轴的共同作用,出苗动力强;而短胚轴顶土出苗动力主要来源于芽鞘节的伸长,出苗动力较弱。还对通过选育长胚轴直播稻品种解决直播稻易倒伏和出苗差等难题的可能性进行了探讨。     

蓖麻器官间干物质分配的预测模型

为实现蓖麻生长的数字模拟和预测,在前人研究基础上,构建了蓖麻器官间干物质分配的预测模型。用Richards方程来表达叶片、茎秆、根和蒴果的分配指数的变化动态。引入分配指数最大值作为遗传参数来区分不同品种的器官间干物质分配特性,对于通蓖5号、通蓖6号、通蓖9号和中东等4个品种的叶片、茎秆、根和蒴果,分别赋予了分配指数的最大值。引入氮肥影响因子来区分不同施肥水平的养分效应。不同地区的检验结果表明,蓖麻各器官干物重观测值与模拟值的绝对预测误差为0.64~19.34g,RMSE为1.01~11.43g。模型显示出较好的预测性。     

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.     

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.     

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.     

Extreme resistance to infection by potato virus X in genotypes of wild tuber-bearingSolanum species

Summary Clones derived from thirty-one different accessions (nineteen of Argentine origin) belonging to eightSolanum species were screened for resistance to infection by potato virus X strain cp (PVX cp) by mechanical inoculation of plantlets that had been micropropagated in vitro. Estimates of PVX multiplication obtained by enzyme linked immunosorbent assay and slot blot nucleic acid hybridization allowed the identification of resistant clones derived from five accessions belonging toS. commersonii S. oplocense, S. sparsipilum andS. tuberosum andigena. Resistant genotypes supported PVX concentrations 5 to 15 times smaller than did the susceptible control cultivar Spunta. Graft inoculation test confirmed the presence of extreme resistance similar to that conferred by the ‘immunity’ gene X¹ (also called RX_act).     

Cyanobacteria Secondary Metabolites as Biotechnological Ingredients in Natural Anti-Aging Cosmetics: Potential to Overcome Hyperpigmentation,Loss of Skin Density and UV Radiation-Deleterious Effects

The loss of density and elasticity, the appearance of wrinkles and hyperpigmentation are among the first noticeable signs of skin aging. Beyond UV radiation and oxidative stress, matrix metalloproteinases (MMPs) assume a preponderant role in the process, since their deregulation results in the degradation of most extracellular matrix components. In this survey, four cyanobacteria strains were explored for their capacity to produce secondary metabolites with biotechnological potential for use in anti-aging formulations. Leptolyngbya boryana LEGE 15486 and Cephalothrix lacustris LEGE 15493 from freshwater ecosystems, and Leptolyngbya cf. ectocarpi LEGE 11479 and Nodosilinea nodulosa LEGE 06104 from marine habitats were sequentially extracted with acetone and water, and extracts were analyzed for their toxicity in cell lines with key roles in the skin context (HaCAT, 3T3L1, and hCMEC). The non-toxic extracts were chemically characterized in terms of proteins, carotenoids, phenols, and chlorophyll a, and their anti-aging potential was explored through their ability to scavenge the physiological free radical superoxide anion radical (O₂^•−), to reduce the activity of the MMPs elastase and hyaluronidase, to inhibit tyrosinase and thus avoid melanin production, and to block UV-B radiation (sun protection factor, SPF). Leptolyngbya species stood out for anti-aging purposes: L. boryana LEGE 15486 presented a remarkable SPF of 19 (at 200 µg/mL), being among the best species regarding O₂^•− scavenging, (IC₅₀ = 99.50 µg/mL) and also being able to inhibit tyrosinase (IC₂₅ = 784 µg/mL), proving to be promising against UV-induced skin-aging; L. ectocarpi LEGE 11479 was more efficient in inhibiting MMPs (hyaluronidase, IC₅₀ = 863 µg/mL; elastase, IC₅₀ = 391 µg/mL), thus being the choice to retard dermal density loss. Principal component analysis (PCA) of the data allowed the grouping of extracts into three groups, according to their chemical composition; the correlation of carotenoids and chlorophyll a with MMPs activity (p < 0.01), O₂^•− scavenging with phenolic compounds (p < 0.01), and phycocyanin and allophycocyanin with SPF, pointing to these compounds in particular as responsible for UV-B blockage. This original survey explores, for the first time, the biotechnological potential of these cyanobacteria strains in the field of skin aging, demonstrating the promising, innovative, and multifactorial nature of these microorganisms.     

Marine Pharmacology in 2009–2011: Marine Compounds with Antibacterial,Antidiabetic, Antifungal,Anti-Inflammatory,Antiprotozoal, Antituberculosis,and Antiviral Activities; Affecting the Immune and Nervous Systems,and other Miscellaneous Mechanisms of Action ?

The peer-reviewed marine pharmacology literature from 2009 to 2011 is presented in this review, following the format used in the 1998–2008 reviews of this series. The pharmacology of structurally-characterized compounds isolated from marine animals, algae, fungi and bacteria is discussed in a comprehensive manner. Antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral pharmacological activities were reported for 102 marine natural products. Additionally, 60 marine compounds were observed to affect the immune and nervous system as well as possess antidiabetic and anti-inflammatory effects. Finally, 68 marine metabolites were shown to interact with a variety of receptors and molecular targets, and thus will probably contribute to multiple pharmacological classes upon further mechanism of action studies. Marine pharmacology during 2009–2011 remained a global enterprise, with researchers from 35 countries, and the United States, contributing to the preclinical pharmacology of 262 marine compounds which are part of the preclinical pharmaceutical pipeline. Continued pharmacological research with marine natural products will contribute to enhance the marine pharmaceutical clinical pipeline, which in 2013 consisted of 17 marine natural products, analogs or derivatives targeting a limited number of disease categories.     

Recent Modifications of Chitosan for Adsorption Applications: A Critical and Systematic Review

Chitosan is considered to be one of the most promising and applicable materials in adsorption applications. The existence of amino and hydroxyl groups in its molecules contributes to many possible adsorption interactions between chitosan and pollutants (dyes, metals, ions, phenols, pharmaceuticals/drugs, pesticides, herbicides, etc.). These functional groups can help in establishing positions for modification. Based on the learning from previously published works in literature, researchers have achieved a modification of chitosan with a number of different functional groups. This work summarizes the published works of the last three years (2012–2014) regarding the modification reactions of chitosans (grafting, cross-linking, etc.) and their application to adsorption of different environmental pollutants (in liquid-phase).