气候变化对河南省夏玉米单产的影响分析

根据河南省代表站点夏玉米历史气候资料、单产资料及生育期观测资料,分析夏玉米不同生长时期气候要素及相对气候产量的变化规律,通过划分不同的基准时段,分析气候变化对河南省夏玉米单产的影响率。结果表明,代表站点夏玉米营养生长期及全生育期平均气温呈三次多项式变化,不同生长时期日照时数显著递减,降水量波动较大。1961~1981年夏玉米相对气候产量较稳定,并与营养生长期气温呈显著负相关;1988年以后相对气候产量年际间变异明显增大,并与生殖生长期的降水呈显著负相关。与1961~1981年相比,90年代以来气候变化对河南省夏玉米单产的影响率为-2.1%~-9.3%;与1991~2000年相比,21世纪以来的气候条件对夏玉米产量形成有利,影响率为4.7%。     

吉林省气候变化对玉米气象产量的影响

利用吉林省梨树县1986～2008年的气象资料和玉米产量资料,在确定梨树县玉米的气象产量与积温、降雨以及日照时数之间关系的基础上,分析吉林省气候变化规律及其对玉米产量的影响。结果表明：玉米的气象产量(Y_w)与降雨量(x₁)呈显著正相关,与生育期内的积温(x₂)呈显著负相关,与日照时数无显著相关关系,与生育期内的降雨量和积温存在显著的二元线性关系：Y_w=15768.77+2.87x₁-5.42x₂,(r=0.63)。吉林省整个生育期内的平均气温、积温分别以每年0.05℃和10℃左右增加,降雨量以每年5mm左右减少,日照时数没有明显变化。随着吉林省气候变暖和降雨减少现象的加剧,对吉林省的旱情和玉米产量的影响越来越重。     

贵州春玉米茎秆性状与气象因子的关系

在贵州5个玉米亚区以先玉1171、新中玉801、金玉838和兴玉3号4个玉米品种为试材,通过灰色关联度、相关性分析等方法研究主要气象因子与玉米茎秆性状的关系,进一步研究贵州春玉米茎秆性状的主要气象因子对其的影响程度,为贵州耐密抗倒春玉米布局及高产栽培调控提供科学依据。结果表明,有效积温对压折强度和纤维素的含量影响最大,日照时数对节间长度和扁率的影响最大,日均温和降水量分别对穿刺强度和横截面积的影响最大,日平均风速对茎秆特性指标的影响均最小。温度和降水量对茎秆力学特性和纤维组织成分影响较大,茎秆的形态特性受光照影响较多。气象因子对玉米茎秆特性的影响为有效积温日均温降水量日照时数日平均风速,其中影响贵州不同生态亚区茎秆特性的主要气象因子为温度和降水量。     

吉林省玉米气候适宜性评价研究

玉米生长发育和产量的形成与气象条件密切相关,气候波动是造成玉米单产不稳定的主要原因。以吉林省为研究区域,选取有代表性的20个地区,对各个地区玉米生育期内12个气象指标进行主成分分析,提取出2个主成分进行聚类分析,从而将吉林省划分为3个玉米种植生态区。利用GIS软件绘制出吉林省玉米气候适宜性区划图,并进行气候适宜度评价。     

气象要素对凤阳县棉花产量的影响

本文以１９６７～１９９６年３０年的气象资料和凤阳县历年棉花单产，应用多项回归和逐步回归等方法对影响棉花单产的主要气象因子进行分析。结果表明，近１０年棉花产量的１８．５７％决定于气候条件。其中显著影响棉花产量的因素有：≥１２℃累计积温、５～１０月累计降雨量、７月中旬到８月的旬均温累计温度和日照时数。纤维成熟度１．６的棉铃有效开花期为８月２５日，并提出了相应的配套技术。     

基于气候适宜度指数的吉林省大豆单产动态预报研究

为及时、准确地进行大豆产量预报,给相关部门提供可靠依据保障吉林省粮食安全,利用吉林省1980-2016年大豆产量、生育期、逐日气象数据,基于大豆生长发育的生物学特性(最适温度、上限温度、下限温度、需水量、需光性等),构建大豆生长季逐旬温度、降水、日照时数及综合气候适宜度模型,通过与相对气象产量进行相关和回归分析,建立基于气候适宜度指数的7-8月逐旬产量动态预报模型,对吉林省大豆产量进行动态预报。结果表明:各时段建立的产量预报模型均通过0.05水平的有效性检验,能够客观反映大豆生长期内气象要素状况;各预报模型的历史回代检验平均准确率均大于85.0%,均方根误差小于20.0%;历史回代拟合的气象产量与实际气象产量在年际变化上具有较好的一致性,两者相关性通过0.05水平的显著性检验;在1981-2014共34年中各旬单产趋势预报准确的年份均在24年以上。各时段预报模型对2015-2016年的外推预报准确率分别在92.0%和81.4%以上,趋势预报不稳定,可能与模型没有考虑灾害影响有关。总体上,构建的产量预报模型可为吉林省大豆产量预报提供参考依据。     

气象条件对广西春大豆生长发育及产量的影响

本文用1983—1985年广西春大豆区试播种资料与气象资料进行了相关统计分析。结果表明,影响广西春大豆各生育阶段生育日数的关键气象因子:播种至出苗期为土壤温度;出苗至始花期为日平均气温和降水日数;始花至成熟期为日照时数;出苗至成熟期为降水日数。影响产量的关键气象因子为始花至成熟期的温度日较差、平均相对湿度和降水量。温度日较差和降水量对广西春大豆各生育阶段生育日数的影响不显著。     

基于小波分析的水稻生育期气象因子对产量的影响

为水稻产量趋势化及定量化预报提供依据,对水稻全生育期气象因子与产量的影响关系进行分析。提取1986—2015年间辽宁省水稻产量数据和同期时序气象数据,对水稻气象产量及同期时序气象因子进行连续小波分析,研究水稻气象产量、日照时数、日平均气温等气象因子的时序变化特征;分别利用相干小波分析和交叉小波分析方法,研究水稻气象产量与日照时数、日平均气温等气象因子的相互关系。结果表明:1)辽宁省水稻气象产量存在5~8年和2~3年的显著周期,自2001年之后,水稻在频率上的能量强弱分布不显著,表明气象产量连续丰年的周期在变长;2)对水稻生育期内的气象因子进行连续小波分析,其中除总降水量外,其他气象因子均都存在不同的显著周期。     

冬小麦不同生长阶段气象因素对产量影响的双重量化分析

为探究冬小麦各生育期的气象因素对其产量的影响程度,根据黄淮海冬小麦物候图将冬小麦生育期划分为9个生长阶段,选取河南省2005-2015年冬小麦的产量数据和日平均气象观测数据,利用指数平滑法计算出冬小麦的气象产量,建立气象影响因素集和灰色关联分析模型,双重量化分析河南省冬小麦不同生长阶段气象因素对产量的影响程度。结果表明,单重量化分析时,在播种期、分蘖期、越冬期和灌浆期,平均相对湿度对冬小麦气象产量影响最大;在返青期、拔节期和成熟期,平均风速对冬小麦气象产量影响最大;出苗期日平均气温对冬小麦气象产量影响最大;抽穗期光照时长对冬小麦气象产量影响最大。双重量化分析时,出苗期平均气温和日最高气温、分蘖期和越冬期平均相对湿度、拔节期平均风速对冬小麦气象产量影响较大。     

超高产栽培条件下气象条件对夏玉米产量的影响

根据山东莱州和河南温县多年进行的夏玉米超高产栽培试验资料,分析了夏玉米产量构成因素以及气象条件与产量构成因素的关系。结果表明：在夏玉米超高产栽培条件下,产量构成因素对产量的贡献大小顺序为穗粒数>穗数>粒重;影响穗粒数的关键气象因子是播种后第6、8旬(从播种期所在旬记起,下同)的降水量和第6旬的日照时数。     

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.     

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.     

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.