根瘤菌对大豆根际土壤微生物及大豆农艺性状的影响

为研究施用根瘤菌条件下,大豆不同生育期土壤中微生物数量的动态变化及其对大豆农艺性状的影响,于大豆苗期、花期、结荚期、鼓粒期、成熟期分别对大豆根际土壤细菌、真菌、放线菌采用平板计数法进行数量测定;于大豆成熟期对大豆农艺性状及产量进行测定。结果表明:大豆根际土壤微生物数目随大豆生育期不同而发生变化。与对照相比,根瘤菌的施用均增加了除花期外各时期土壤中细菌的数量,在结荚期、鼓粒期和成熟期,增加了土壤真菌数量,在结荚期和成熟期增加了土壤放线菌数量;根瘤菌的施用增加了大豆的株高、主茎节数、单株荚数和单株粒数,且有效增加了大豆产量,与对照相比增产19.44%。     

根际渍水对大豆叶绿素含量的影响

8个品种分别在V_3、R_1、R_3期渍水14天、20天和30天测定叶绿素含量,结果表明R_1期是大豆渍害的敏感时期,此期渍水使叶绿素含量明显下降,品种不同,下降的幅度差异较大宝交83—5029、合丰25下降的幅度较小。     

大豆品种鼓粒期田间抗旱鉴定

大豆鼓粒期缺水是制约大豆产量形成的重要因素之一。在鼓粒期对大豆品种进行抗旱性鉴定,可为大豆抗旱育种和抗旱节水栽培提供依据。选取不同地区育成的代表性品种（品系）46份,在鼓粒期田间干旱与灌水条件下,分析其产量、产量性状、生育期与形态性状、籽粒品质性状等指标,并且对其进行抗旱性鉴定。结果表明,干旱区46份材料平均产量1 759.6 kg/hm²,灌水对照区平均产量2 223.1 kg/hm²,46个品种平均耗水系数1.079 t/kg。干旱对三粒荚影响显著,对单株荚数、单株粒数、生物产量、单株粒重、百粒重影响极显著。干旱区的平均蛋白质含量极显著高于灌水区,比对照区提高幅度4.47 %;平均脂肪含量极显著低于灌水区,比正常灌水区降低幅度4.19 %。干旱条件下品种百粒重下降,生育期提早均属于品种抗旱性的适应反映,与抗旱性无关。适于呼伦贝尔的品种推荐为北豆14、黑河50、黑河43、华疆3、登科1号、蒙豆15、北豆37、黑河36、北豆38等。     

新疆高产春大豆鼓粒的粒位差异研究

为探明新疆高产春大豆鼓粒的粒位差异,明确粒重增加的规律,2015-2016年在田间研究了金元20、11-109、新大豆27和黑农61,4个中熟高产春大豆品种(系)主茎不同节组荚、同节异荚、三粒荚各粒的鼓粒进程及单粒重的变化规律。结果表明:不同品种(系)的主茎基部1~3节的荚最早开始鼓粒、鼓粒期最长、单粒重最低,顶部倒1~3节荚始粒期最晚、鼓粒期最短,单粒重介于基部1~3节与顶部倒4~6节之间,顶部倒4~6节荚的始粒期和鼓粒期介于基部1~3节与顶部倒1~3节之间,其单粒重最大。主茎荚始粒期、鼓粒期的差异随节位的差异而增大,节组间最大差异分别为9~24 d和6~15 d;同节位的大、中荚比小荚始粒期早、鼓粒期长、单粒重大;三粒荚各粒增重速度和单粒重均表现为中远近粒位;鼓粒进程及单粒重的差异表现为同株异节同节异荚同荚异粒。鼓粒过程对大豆产量的影响是通过影响单粒重实现的,鼓粒的粒位差异大,增加大豆单株鼓粒期,对高产有利。春大豆产量5 000~5 600 kg·hm-2的单株鼓粒期为45~60 d。     

不同品种大豆的产量及质膜透性对水分胁迫的反应

本研究是1984年在黑龙江省农业科学院,用盆栽,在不同生育期人工模拟旱境的条件下进行的。试验结果表明,不同品种的基础产量水平虽然不同,但其产量及产量因子对不同生育时期的干旱胁迫,有着基本一致的反应。也就是说,干旱胁迫对其相应时期的生长发育有较大的影响。如荚形成时期和鼓荚时期的干旱胁迫,致使秕荚大量增加,粒数减少;鼓粒期的干旱胁迫且导致百粒重的下降。荚鼓期的干旱胁迫造成产量大幅度下降,主要是因为粒数的减少和百粒重的降低等综合因素所致。但是其减产幅度的大小,因品种的抗旱性而异。如抗旱品种“呼80—1001”减产10％,对照品种“黑农26”减产17.9％,而不抗旱品种“绥农4号”减产39.2％。从总的趋势看,大豆基础细胞质膜透性,随生育期的进展,直至鼓粒期,均有增加的趋势,但质膜透性存在着品种间差异。在干旱条件下,细胞质膜的相对变化因品种,因生育期而异。荚鼓期的水分胁迫,对细胞质膜的伤害最严重,这与荚鼓期的水分胁迫对产量的影响是相一致的。说明,在干旱胁迫条件下,品种的质膜透性,与其抗旱性有密切的关系。     

荷泽地区夏大豆亩产200公斤的生育规律研究

经田间试验,对不同产量水平大豆的生育动态进行比较,结果表明:黄淮流域夏播大豆,以选用生育期近100天,株形紧凑的中秆或矮秆品种,适当提高密度,较易获得200kg/亩以上的稳定高产。其株高、单株干重与叶面积增长积累动态,呈苗期较慢,花荚期开始转快,鼓粒期减缓的“S”形曲线,各转折点变化较小,曲线较平滑有利于高产。200kg/亩以上大豆的生物产量与粒/茎较高,在提高单株荚、粒数的基础上,百粒重对产量的贡献程度相对加强,较高的叶面积系数与干物质积累,尤其是鼓粒期间保持较高的光合势与群体干物质增长量,是取得200kg/亩以上产量的必要条件。     

大豆根潜蝇发生为害及防治的研究

1983～1989年研究大豆根潜蝇的发生为害及防治规律,取得以下结果:①大豆根潜蝇主要在大豆苗期为害,使地下根长度、支根数及根瘤数降低,地上叶片内叶绿素含量减少,植株干重降低14.47～28.57％。受害株荚数、豆粒数和百粒重降低,单株产量降低23.48％,使大豆减产15.82％。②大豆与玉米轮作被害率较连作低48.73％。于根潜蝇化蛹期(大豆始花期)追肥能加速虫伤愈合、发根并能挽回受害损失40—50％。③应用辛硫磷、3911 0.1％(种子量)的量拌种防效均达100％,较对照有明显的增产作用,增产达10—15％。     

黄淮海地区夏大豆农艺性状与产量的多元回归和通径分析

应用多元统计方法,分析了黄淮海地区73份夏大豆农艺性状与产量之间的关系。结果表明:影响夏大豆产量的主要农艺性状因品种结荚习性的不同而有所差异。在亚有限型大豆品种中,每荚粒数、单株荚数、株高和单株粒重对产量的直接作用较大;在有限型大豆品种中,单株粒数、生育期、茎粗和株高对产量的直接作用较大。在品种选育上,对于亚有限大豆品种,应优先选择单株粒重较高的单株,尤其是注重多荚和多粒性状的选择;对于有限型大豆品种,应选择生育期与单株粒重间平衡较好的单株,能充分发挥高产潜力。     

夏大豆花荚期受渍胁迫对农艺性状、产量与品质的影响

为了探索平原湖区易涝易渍耕地种植夏大豆的排水管理 ,选择大豆关键生育期—花荚期进行了不同水处理试验 ,研究了夏大豆不同受渍胁迫对农艺性状、产量及品质的影响。结果表明 ,受渍胁迫引起大豆单株粒数、单株荚数、单株粒重、百粒重等降低 ,从而导致减产。随着受渍时间的延长 ,减产幅度增大 ;籽粒中粗脂肪含量增加 ,粗蛋白含量下降 ,但是 ,各受渍处理间两者总含量差异不明显。     

不同生育阶段剪叶量对大豆品种南农99-6农艺和品质性状的影响

筛选大豆对叶片机械损失敏感的指标和时期,为评价大豆对食叶性害虫的耐虫性及制定虫害防治指标等提供参考。在大豆品种南农99-6不同生育阶段(V5、R1、R3、R5)进行不同程度(0%、16. 7%、33. 3%、50. 0%、66. 7%、83. 3%和100%)的剪叶处理,测定农艺和品质性状,以探究不同生育阶段不同叶片损失程度对农艺和品质性状的影响。结果表明:(1)不同剪叶量处理间,单株产量、单株荚数、四粒荚数、三粒荚数、二粒荚数和株高差异达极显著水平,主茎节数、一粒荚数和百粒重差异达显著水平,有效分枝数、每荚粒数及蛋白质含量和油脂含量没有显著差异;一粒荚、二粒荚、三粒荚和四粒荚的数量都有随剪叶量增加逐步减少的趋势。(2)平均单次33. 3%及以上的叶片损失可导致单株荚数显著减少; 50%及以上的叶片损失可导致单株产量显著降低;而100%叶片损失可导致百粒重显著降低。(3)不同生育期剪叶处理间百粒重、三粒荚数、单株荚数和单株产量差异达到或接近显著水平,而其它性状无显著差异。始荚期的叶片损失对单株荚数影响最大,而鼓粒始期的叶片损失对百粒重影响最大且同时影响单株荚数,因而R3和R5是叶片损失的敏感时期。(4)不同生育阶段与不同剪叶量间的互作对大豆农艺和品质性状的影响较小,都未达到显著水平。(5)该试验结果模拟了大豆受咀嚼式食叶性害虫危害的机械损伤影响,但不涉及取食时分泌唾液毒害和刺吸式口器害虫吸食的影响。(6)建议用虫害关键时期(R3) 33. 3%的剪叶量模拟咀嚼式食叶性害虫危害,以单株荚数损失率、百粒重损失率及单株产量损失率作为评价指标鉴定大豆的耐虫性。     

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.     

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.