杂交早稻旱育秧苗分蘖特性研究

对杂交早稻旱秧和水秧分蘖发生，成穗和结实进行了定点追踪比较，结果表明，旱秧分蘖发生和成穗优势明显，不仅发生数和成穗数较水秧多，且分蘖发生和成穗高峰节位以及一次分蘖穗粒数和单穗最大的节位分别较水秧低一个节位，旱秧小苗分蘖产量优势主要表现为大穗优势，而中苗和大苗分蘖产量优势秀现为穗数优势。     

水稻旱育秧栽培技术研究

自1992年引进水稻旱育秧技术，经过五年的试验研究，前四年侧重于旱育秧的播种量，移栽叶龄、密植规格、秧床培育、丛括本数、适宜播期、氮肥施用等方面研究。1997年，侧重旱育抛栽、秧床除草、技术体系、再生稻旱育、制种旱育、旱秧避害、秧床控水、优化技术等方面开展试验研究，现将结果报导如下。一、早稻旱育秧栽培技术研究试验设在长汀县农科所，供试组合为协优64，进行旱育秧与湿润秧二大技术对比。从育秧到大田管理，两种育秧方式均按各自的栽培特点与技术要求进行操作。在水管上，旱育秧前期以露为主，排灌结合；湿润秧前期寸水护苗…     

早稻地膜旱土育秧技术

早稻地膜旱土育秧是一种新型的育秧技术，它的特点是利用旱地育秧，秧田面积少，1m2秧田可移栽30m2大田，秧田管理方便。该技术具有以下优点：一是经济效益高，不仅地膜用量只有常规水秧的三分之一（因秧田面积只有常规水秧的三分之一），而且成秧率高，用种省，肥料利用率高，每公顷大田可节约物化成本150元左右；二是出苗整齐，安全可靠，不会因播后天气恶劣而烂秧，可解决农民怕播种烂秧的后顾之忧；三是可适时早播早插以利于早熟高产，早晚两季平衡增产；四是秧苗素质好，短白报多，干物质含量高，抗逆能力强，插后返青分案快，能有效地…     

杂交晚稻旱地育秧技术

1981年以来,,萍乡市桐木乡为了增加早稻种植面积,压缩晚稻专用秧田,以增加稻谷总产,1981-1982年分别在全乡不同土质、肥水管理及光照条件的山区、丘陵、盆地进行了杂交晚稻旱土育秧试验示范,获得了成功。成片面积产量验收结果,平均亩产达432公斤,最高的示范户和典型丘亩产达580公斤,比相同管理的水秧亩产提高20公斤。 实践证明:推广杂交晚稻旱土育秧,既可增加早稻种植面积和早稻总产,又可以充分利用旱土秧在大田分蘖早、快、多的优势,增加成穗数,提高晚稻单产。 旱土育秧方法简便,要求做到: 一、掌握“三期”、卡住“二最” 汕优2号掌握在6…     

水稻无载体培育机插秧苗技术

水稻无载体培育机插秧苗技术在育秧过程中不需使用任何育秧载体材料,培育好的水稻秧苗用专用切秧装置进行切秧处理后,形成标准规格的秧片,配套用于插秧机实现机械插秧。与目前生产上普遍使用的有载体(塑料秧盘、打孔地膜、塑料编织布)育秧机插技术相比,具有成本低廉,     

中苗带土秧在早稻高效栽培上的效应浅析

湖南早稻育秧方法几经改进，逐步形成了目前薄膜水秧、大酋洗插为主的格局。但这种方法仍不免有烂种、烂秧现象，加上扯秧、洗秧、缚秧、运秧、抛秧和分秧几个环节的机械损伤，不仅成秧率低（一般在70％以下），而且插到大田以后有返青期，因而缩短了本来有限的有效分率期，使大田很难达到高产苗穗数，制约了早稻的单产。为了解决这一问题，“湖南水稻生产高效技术工程研究”课题组从1995年开始采用中苗带上移栽的方式进行试验、示范，取得了可喜的效果。湖南省望城县开始有三个乡镇参加示范，面积共18.3hm2。结果，同一品种的中苗带土秧比…     

寄秧期僵苗原因及防治技术

寄秧期僵苗是削弱杂交水稻两段育秧增产、增益优势的重要因素之一,我县注意总结和推广寄秧期僵苗防治技术,取得较好成效。1985年,全县杂交水稻两段育秧面积48680亩,寄秧期僵苗面积仅36亩,不足0.l%,两段育秧比露地育秧每亩大田平均多收稻谷79公斤,增加收益20元左右。现将两段育秧寄秧期僵苗发生原因及防治技术介绍如下: 一、僵苗原因 1.小苗超龄。要培育壮秧,寄栽时小苗叶龄以越小越好,但苗龄小,寄栽成活率较低,对整地的要求也高。生产上如果到2-3叶期才寄栽,这种小苗抗寒力弱,正处于从异养转入自养的过渡时期,胚乳养料已逐渐耗尽,又没有较强…     

杂交中稻地膜“四秧”生育特性研究

已有研究表明,地膜育秧具有增温、保温、提高成秧率和早熟、高产、节能、省工、低成本等效果。大面积生产上则根据稻田类型、不同栽培方式,采用小苗、中苗、大苗和长龄秧等四种秧苗配套种植,可以调节季节、水、肥、劳、畜力矛盾。本文对四种移栽叶龄的秧苗素质,产量及其生育特性进行分析,为大面积生产选用适宜秧苗类型提供依据。 一、材料和方法 供试组合为汕优63、汕优2号。1986年3月15日播种,地膜拱架式育秧,“四秧”移栽叶龄为小苗1.5叶,中苗5叶,大苗8叶和长龄秧11叶。种子经消毒浸种,电热发芽箱催芽,每亩播种量:小苗300公斤,中苗40公斤,…     

不同育秧基质对水稻秧苗素质的影响

利用5种不同育秧基质替代营养土在安徽安庆培育水稻机插秧苗,调查分析了各处理的出苗率、成秧率、地上部秧苗素质、根系、干鲜质量。结果表明,用水稻育秧基质育苗能够明显提高机插秧苗素质和成秧率,尤以安徽绿福农业科技股份有限公司和安徽安庆亿科育苗材料有限公司生产的育秧基质优势更明显。建议大面积推广水稻基质育秧,为夺取水稻高产、优质、高效奠定坚实的基础。     

杂交稻制种父本旱育、稀寄、密植栽培技术探讨

针对过去父本育秧采用板田铺泥浆育小苗的缺陷，把旱育秧技术与移栽灵混剂相结合应用到父本育秧上，有效防止了播后烂秧和寄后死苗现象。同时通过旱秧稀寄，不盖膜，达到了秧苗分蘖早、分蘖多、栽后存活率高，加上栽培上适当密植，使父本总颖花量大大提高。     

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).