不同生育时期干旱对大豆主要生理参数及产量的影响

研究了不同生育时期干旱对大豆光合速率、硝酸还原酶活性、磷酸蔗糖合成酶和蔗糖合成酶活性等生理指标的影响以及对产量和产量构成因子的影响.结果表明,不同生育时期进行干旱处理均使光合速率硝酸还原酶活性、蔗糖合成酶活性和磷酸蔗糖合成酶活性降低,光合速率以分枝期到鼓粒期干旱处理降低幅度较大,硝酸还原酶活性以开花期干旱处理降低幅度最大,其次是分枝期和鼓粒期;蔗糖合成酶活性和磷酸蔗糖合成酶活性以开花期干旱处理降低幅度最大,其次是鼓粒期和分枝期;不同生育时期干旱处理均导致大豆产量构成因子和产量下降.每株荚数和每荚粒数以结荚期干旱处理降低幅度最大,其次是鼓粒期干旱处理、开花期干旱处理;百粒重以鼓粒期干旱处理降低幅度最大,其次是结荚期和开花期干旱处理.单株产量以结荚期干旱处理降低幅度最大,其次是鼓粒期、开花期干旱处理.开花期、结荚期和鼓粒期干旱对产量影响最大,在大豆生产中要特别注意这几个生育时期的水分管理.     

高产大豆品种的生理特征和产量性状研究

2009～2010年,以普通大豆品种九农21为对照,比较了其与高产品种长农13和吉育88的生长动态、主要农艺性状及产量,并对形态指标和产量构成因素进行了典型相关分析。结果表明:高产品种的叶面积指数、地上部生物量、根系指标(根系活力、伤流量、根系体积和干重)、产量以及株高、单株荚重、单株粒重和百粒重等主要农艺性状均高于对照品种,但主茎节数和分枝数低于对照;通过典型相关分析发现,单株粒重与R5期根系体积呈显著正相关,而与R6期叶面积指数呈显著负相关,表明合理调控鼓粒期的群体结构,有助于增产。     

大豆主要生育性状与产量间的关系分析

生育期、株高、分枝数、主茎节数、单株荚数、百粒重等性状是大豆主要生育性状.通过对生育期、株高、分枝数、主茎节数、单株荚数、百粒重等性状的相关分析和灰色关联度分析,结果表明,分枝数、单株荚数是影响产量的关键因素.     

高温干旱混合胁迫对大豆主要农艺性状的影响

干旱与高温常常相伴发生,会使大豆受害程度加剧。为了解高温干旱双重胁迫对大豆农艺性状的影响,选取了160个大豆品种,采用一点两年重复实验,在高温干旱双重胁迫和正常条件下进行种植,分析单株荚数、分枝数、百粒重、株高、单株粒数等性状。结果表明:高温干旱双重胁迫使大豆群体株高、主茎分枝数、单株粒数、单株荚数、百粒重呈下降趋势,分别下降34%、36%、60%、62%、49%,其中也有部分材料性状会有升高或不变,胁迫下株高有6%的材料变高、5%的材料没影响,单株荚数未见增加的材料,有3%材料不变,分枝数有15%材料增加,7%不变,单株粒数有9%材料升高、4%不变,百粒重有4%增加、3%未见变化。在两种生境下,株高、单株荚数、单株粒数、主茎分枝数之间相关性变化不明显,百粒重与其它性状相关性发生明显变化,同时发现两种环境下性状变异系数除株高外变化都很明显。     

大豆种子性状、幼苗性状及经济性状间的相关性分析

用22个种子性状差异较大的大豆品种,在测量种子百粒重、百粒容积和容重后,进行田间试验,测定各品种幼苗性状及经济性状的平均值,计算大豆种子性状、幼苗性状及经济性状的相关系数。结果表明:大豆种子粒重和容积与出苗率呈极显著负相关,与幼苗叶绿素含量和基茎粗呈极显著正相关,与幼苗根、茎、叶干物重呈显著或不显著的正相关,与后代百粒重和单株产量呈极显著正相关。幼苗叶绿素含量高的品种,单株分枝数和单株荚数多,百粒重和单株产量高。幼苗茎干重和根干重对单株分枝数和单株产量有显著影响,基茎粗与百粒重呈显著相关。选用大粒品种,既可培育壮苗,又可获得较高的单株产量。     

黑龙江省大豆主栽品种主要性状灰色关联度分析

为了寻求对黑龙江省三江平原地区大豆产量影响较大的主要农艺性状,从而为龙江地区大豆育种工作提供理论依据.应用灰色关联度分析方法,分析黑龙江省大豆品种主要性状对其产量的影响.结果表明:产量与主要性状的关联度大小依次为单株粒数＞单株荚数＞结荚层数＞有效分枝＞株高＞主茎节数＞百粒重＞单株粒重＞底荚高度,对黑龙江省大豆产量影响最大的是单株粒数,影响较大的是单株荚数、结荚层数,影响中等的是有效分枝＞株高＞主茎节数＞百粒重,影响较小的是单株粒重和底荚高度.     

套作大豆农艺性状与产量的关系研究

通过模拟"玉米-大豆"带状套作,分析了133份大豆材料的农艺性状与产量的关系。结果表明:参试大豆材料表型性状的变异系数为6.44%~52.49%,各性状平均遗传多样性指数达到1.929 3,说明参试大豆材料存在比较丰富的表型多样性。相关分析表明,产量与主茎节数、有效分枝数、单株荚数、每荚粒数、分枝粒重、分枝粒重占比、营养生长期、生育期呈极显著正相关关系。多元线性逐步回归得到7个与产量呈极显著的农艺性状,正效应因子排序为:每荚粒数分枝粒重百粒重主茎节数单株荚数营养生长期,负效应因子为株高。对这7个农艺性状的通径分析表明,综合效应排名为:分枝粒重单株荚数主茎节数营养生长期每荚粒数株高百粒重。根据主成分得分并借助权重计算的综合得分把133份大豆材料聚类成4类,其中第Ⅳ类大豆分枝数、单株荚数、每荚粒数和主茎节数较多,营养生长期和生育期较长,株高适中,百粒重较小,底荚较高,适宜在套作模式中推广。     

套作大豆高产优质育种的灰色关联分析

通过模拟"玉米-大豆"带状套作,采用灰色关联分析法分别分析了高产材料(≥1 500 kg·hm-2)的产量、高蛋白材料(≥50%)的蛋白质含量、高脂肪材料(≥20%)的脂肪含量与农艺性状的相关性。结果表明:3种类型大豆材料中,有6个农艺性状的变异系数都大于10%,特别是高脂肪材料的底荚高、分枝数和单株荚数的变异系数均大于30%,说明通过农艺性状的选择,提高大豆产量、蛋白质含量和脂肪含量的潜力较大。套作下高产材料、高蛋白材料和高脂肪材料与农艺性状的关联顺序分别为:生育期株高分枝数底荚高单株荚数百粒重主茎节数;生育期主茎节数株高底荚高分枝数百粒重单株荚数;生育期底荚高百粒重株高主茎节数分枝数单株荚数。套作下,高产材料的产量与蛋白质含量呈极显著正相关(r=0.873**),与脂肪含量呈显著负相关(r=-0.709*);高蛋白材料的产量与蛋白质含量、高脂肪材料的产量与脂肪含量相关均不显著。以上结果表明,选择生育期长的品种可提高套作大豆产量、蛋白质及脂肪含量;选择分枝数、单株荚数较多和株高适中的品种可以同时提高套作大豆产量与蛋白质含量;加强对底荚高和百粒重的选择有望提高套作大豆脂肪含量。     

泸县田坎大豆地方品种数量性状的遗传变异及相关分析

泸县４３个田坎大豆地方唾骂的２９个数量性状的基因型间差异极显著,单株秕荚数,秕荚率、三粒荚型百分主,分枝荚数,百粒重等性状的ＧＣＶ值〉３０％;百粒重,单荚粒数及三粒荚型百分率的广义遗传力〉９０％,单株产量与单株有效荚数,单株粒数,单荚粒数及百粒重,株高及茎粗与单荚粒数及百粒重,单株有效分枝数及主茎结荚节数与单株有效荚数及单株粒数均呈极显著正相关。     

大豆品种(系)耐热性鉴定及分级评鉴

为探讨大豆耐热性评价方法,对大豆进行耐热性鉴定,筛选耐热性分级评鉴指标,以国内外155份大豆品种(系)为材料,设置开花期和鼓粒期两个时期,分别于智能温室进行高温处理12d(40±2℃,9∶00-16∶00/d),以室外自然环境温度为对照。成熟期调查百粒重(X_1)、单株粒重(X_2)、单株荚重(X_3)等13项性状。根据各项性状耐热系数,通过主成分、隶属函数、聚类分析及逐步回归分析对大豆进行耐热性评价和分级鉴定指标筛选。结果表明,通过主成分分析将13个单项指标转化为6个综合指标,经隶属函数分析得出品种(系)开花期和鼓粒期耐热综合评价值D,分别对其进行聚类分析,155份大豆品种(系)在两个处理时期下均被分为6个类型,分别为强耐热型I、耐热型II、中度耐热型III、中度敏感型IV、敏感型V、极敏感型VI。两个处理时期综合评价值D呈极显著相关(r=0.262**),具有一定的一致性。综合两个处理时期鉴定结果,筛选到4个耐热品种(系)和63个热敏感品种(系),同时通过逐步回归分析筛选出百粒重、单株荚重、每荚粒数、茎粗、主茎节数、节间长度、蛋白质含量共7个开花期耐热性的鉴定指标和单株粒重、单株荚重、单株荚数、每荚粒数、地上部干物重、株高、节间长度共7个鼓粒期耐热性的鉴定指标。     

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.