不同品种茶树叶片功能性状及光合特性的比较

以18个茶树品种(系)为研究对象,测量了茶树叶片的叶面积、叶形指数、比叶面积、干物质含量、叶绿素a、叶绿素b及其比值、叶绿素总量、类胡萝卜素及光合特性,并分析了叶片功能性状和光合特性之间的相关性。结果表明,茶树叶片叶形指数、干物质含量、气孔导度的变异系数低于10%,其余11项指标的变异系数为15.08%~43.22%,表现出较高的多样性水平;比叶面积与干物质含量之间存在显著负相关,叶形指数和叶面积与其他叶片功能指标均无显著相关;干物质含量与光合色素之间存在显著相关,叶绿素a、叶绿素b、叶绿素a/叶绿素b、叶绿素总量和类胡萝卜素两两之间存在极显著相关性;净光合速率、气孔导度、蒸腾速率两两之间存在极显著正相关,且气孔导度与胞间CO_2浓度呈显著正相关,茶叶光合速率主要受气孔限制的影响;净光合速率与干物质含量之间存在显著正相关,净光合速率、蒸腾速率与光合色素含量之间存在显著或极显著正相关,说明光合色素含量高的品种具有更强的光合能力和干物质积累能力;气孔导度、水分利用效率与叶片功能性状之间相关性不显著。14号茶树品种比叶面积相对较低,同时具有较高的干物质含量、净光合速率和水分利用效率,属于抗旱性较强、光合速率和水分利用效率高的品种,可作为抗旱性强、高光效的茶树品种进一步选育和应用。     

几种作物叶片主要生理特性的比较研究

在同一条件下,对七种作物叶片的主要生理特性进行同步测定,结果表明:叶片呼吸速率在供试作物间存在显著差异,而其光合速率、总蒸腾速率、角质蒸腾速率,水分扩散导性、CO_2扩散导性及水分利用效率则表现出极显著差异。文中进一步分析了所有测定生理特性间的相关性。     

玉米叶片气孔导度、蒸腾和光合特性研究

玉米叶片气孔导度、蒸腾速率是下表皮高于上表皮。叶片气孔导度的日变化以早上最高,午后下降,18:00时回升;蒸腾速率则在中午最高。果穗叶的蒸腾、光合、叶绿素含量和比叶重高于第9叶和倒2叶。单叶光合速率与可溶性糖、叶绿素含量呈显著正相关,气孔导度与蒸腾速率、全氮含量呈显著正相关,而与比叶重呈显著负相关。高产潜力大的掖单13号较产量潜力小的鲁玉5号,具有较高的光合速率、气孔导度、蒸腾速率、全氮含量、叶绿素含量和比叶重。     

新老大豆品种叶片光合特性的比较

为了了解大豆品种叶片光合特性与产量的关系，我们对跨越70多年的4个老大豆[Glycine max(L.)Merr.]品种和4个新大豆品种的光合特性和产量进行了研究。研究结果表明：新品种产量比老品种提高了91%，新品种叶片净光合速率、气孔导度、蒸腾速率、水分利用效率、叶绿素含量和比叶重也不同程度高于老品种，其中以净光合速率增加最多(17.3%)，而胞间CO2浓度却低于老品种。在盛花期和盛荚期，新老大豆品种叶片净光合速率与产量呈显著正相关（P﹤0.05），而其它光合特性指标与产量的相关性不稳定。     

不同棱型大麦品种旗叶光合性能的差异

为了解不同棱型大麦品种的光舍差异,用LI-6400便携式光合测定仪和分光光度计对10个大麦品种旗叶光合性能和叶绿素含量进行了测定分析.结果表明,各棱型大麦旗叶在叶绿素含量、净光合速率、气孔导度和蒸腾速率花后均呈下降趋势.且棱型与光合性能指标呈显著或极显著相关.二棱大麦旗叶在叶绿素含量、净光合速率、气孔导度、蒸腾速率等方面均显著高于四棱大麦,且叶绿素含量、净光合速率在开花后下降缓慢.     

玉米单叶水分利用效率的差异比较

对6个玉米品种的三个方面,即单叶水分利用效率方差分析、不同水分处理及不同品种玉米单叶水分利用效率的SSR检验和气孔导度、蒸腾速率、光合速率与单叶水分利用效率关系这三个方面对单叶产量水分利用效率角度作了差异比较。农大108光合速率高,蒸腾速率低,单叶水分利用效率最高;哲单39蒸腾速率虽不高,但光合速率很低,导致单叶水分利用效率最低;其余品种居中。在干旱地区可通过选育光合速率对水分胁迫不敏感的品种,增强光合能力,提高水分利用效率,提高产量。     

海岛棉新海21号光合生理特性的初步研究

利用 LI- 640 0 P光合测定系统测定了海岛棉新海 2 1号在花铃期的光合参数。结果显示 ,新海 2 1号的光合速率、蒸腾速率、气孔导度、胞间 CO2 浓度均高于对照新海 1 5号 ,但其水分利用率较低。光合响应曲线反映出其表观光量子效率、暗呼吸速率、光饱和点较高 ,而光补偿点较低。主茎不同节位的叶片光合速率以倒 4叶最高 ,其它参数以倒 1叶最高。叶绿素含量与光合速率在叶片上的分布呈两侧最高、上部大于下部的趋势     

中美大豆Ⅲ熟期组代表品种主要光合特性及其与产量的相关性

中国辽宁省和美国俄亥俄州纬度相同,两地不同年代育成的部分大豆品种具有共同的祖先亲本,本文以两地中期及当代具有共同祖先亲本的大豆品种为材料,研究品种改良过程中光合特性的变化及其与产量的相关性。结果表明:中国辽宁省和美国俄亥俄州大豆品种产量高于共同亲本,且叶片光合特性的变化趋势基本一致。品种叶面积指数、叶色值、净光合速率、气孔导度、蒸腾速率均高于共同亲本,但胞间CO_2浓度随品种育成年代推移而降低;净光合速率、气孔导度、胞间CO_2浓度及蒸腾速率均随生育期进程呈先升高后降低的趋势,且在开花期达到最大值。俄亥俄州当代品种的净光合速率在生育后期下降幅度小于辽宁当代品种;辽宁品种的气孔导度在苗期显著高于俄亥俄品种,胞间CO_2浓度在开花期和鼓粒末期显著高于俄亥俄当代品种;辽宁当代品种的蒸腾速率在整个生育时期均高于俄亥俄当代品种。在苗期、开花期和鼓粒中期,叶色值与产量呈显著或极显著正相关,而蒸腾速率与产量呈显著或极显著负相关。总之,在大豆品种籽粒产量改良的同时,其叶片的光合特性也得到了协同改良。     

不同茶树品种光合特性与冠层指标分析

通过探究不同茶树品种的光合特性,为选育高光效茶树品种及优化栽培管理技术提供参考。以4个茶树品种(‘九龙袍’‘紫玫瑰’‘紫牡丹’‘梅占’)为研究对象,进行表型性状、光合特性以及冠层指标分析。结果表明：在相同环境条件下,4个茶树品种表型性状基本一致;4个茶树品种的蒸腾速率分别与净光合速率和气孔导度呈极显著正相关,净光合速率与气孔导度呈显著正相关,气孔限制值与胞间CO₂浓度呈显著负相关;梅占冠层光合有效辐射和冠层有效截获量始终高于其它品种,而净光合速率略低;紫牡丹的水分利用率高、蒸腾速率低且光能利用率最高,适宜在干旱地区种植。     

黄淮海地区大豆光合特性及高光效种质筛选

本文旨在研究黄淮海大豆种质资源的光合气体交换特性,从中筛选高光效种质,为开展培育大豆高光效品种等研究奠定基础。在大田条件下,以150份来自黄淮海地区的大豆种质资源为试材,利用LI-6400便携式光合仪测定其盛花期的光合气体交换参数,包括叶片净光合速率、气孔导度、胞间CO2浓度、蒸腾速率、叶片饱和水汽压亏缺、蒸腾效率以及叶片瞬时水分利用效率。结果表明,150份大豆种质光合气体交换参数间存在较大差异。7个参数的变异系数范围为5.54%~29.56%,其中,蒸腾效率变异系数最高,胞间CO2浓度最低。净光合速率与气孔导度、叶片瞬时水分利用效率呈显著正相关,与叶片饱和水汽压亏缺呈显著负相关;气孔导度与胞间CO2浓度、蒸腾速率呈显著正相关,与叶片饱和水汽压亏缺、蒸腾效率、叶片瞬时水分利用效率呈显著负相关;胞间CO2浓度与叶片饱和水汽压亏缺、蒸腾效率呈显著负相关;蒸腾速率与叶片饱和水汽压亏缺呈显著正相关,与蒸腾效率、叶片瞬时水分利用效率呈显著负相关;蒸腾效率与叶片瞬时水分利用效率呈显著正相关。进一步利用主成分分析选出3个主成分（气孔因子、水分因子、光合因子）,方差累积贡献率达93.64%。聚类分析将150份大豆种质划分为12个类群,其中第Ⅱ类群包括23份大豆种质,表现高气孔导度、高水分利用率和高光合效率。因此第Ⅱ类群可作为适合育种需要的高光效大豆种质。     

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).