橡胶树乙烯气体刺激短线割制试验效果初报

对树龄20 a以上的RRIM600橡胶树,应用乙烯气体刺激新技术进行短线采胶试验,结果表明：与常规乙烯利刺激割胶相比,在获得省工、高效、节皮的同时,不影响胶树围茎增粗,且胶树死皮相差不大,而单株产量增加0.06 kg。     

乙烯利和乙烯刺激对橡胶树胶乳中几丁质酶活性和胶乳产量的影响

以巴西橡胶树无性系PR107,RRIM600,GT1为试验材料,研究乙烯利和乙烯刺激对胶乳黄色体中几丁质酶活性和胶乳产量的影响。结果表明:在乙烯利和乙烯的有效刺激浓度范围内,几丁质酶活性随乙烯利和乙烯浓度增加而增加;乙烯和乙烯利持续刺激一段时间后,几丁质酶活性达到最大值;3种不同排胶特性品系橡胶树在施用乙烯利刺激后胶乳中几丁质酶活性和胶乳产量较施用乙烯利刺激前均有所增加,其增加强度存在着品系差异,表现为:PR107>GT1>RRIM600。      

乙烯利对胶树形成层活动的影响

在割胶树和不割胶树枝条上施用乙烯利的试验证明,经刺激的割胶树的茎围增长受到影响,这不仅由于刺激增产消耗了同化物,而且由于乙烯利对形成层活动直接的调节作用。乙烯利刺激割胶树茎围增长虽然受到抑制,但由于形成层的活动,韧皮部径向增长的数量(包括乳管列数)受到的影响很小。原因在于乙烯利对形成层活动作用的特点:抑制木质部的增长,促进韧皮部的径向增长。     

海南地区橡胶主要推广无性系的开割标准和割胶制度研究初报

橡胶幼龄芽接树的开割标准和割胶制度应因种制宜。对三个无性系三年试验的初步结果表明,40、45、50厘米三种开割标准,对干胶含量无明显差异,隔两日割(d/3)的干胶含量略高于隔日割(d/2)。割胶对三个无性系的树围增长部有抑制作用,而海垦1在树围40～45厘米开割的,则严重抑制树围增长。从三年亩总产量和其他性状综合比较认为,海垦1无性系45和50厘米开割的,以隔两日割产量略高,而55厘米以上开割的,则以隔日割高产,开割标准应定为50厘米为宜;RRIM600可定为45厘米开割,开割头1～2年以隔两日割较好,以后改为隔日割,初割期采用2％浓度乙烯利刺激割胶,产量增加不多,而不良作用明显,出现死皮的较重;PR107可定为45厘米开割,用隔日割制,割胶2～3年后可试用低浓度乙烯利刺激割胶。     

中龄PR107和热研7-33-97橡胶树“6天1刀”割制的刺激技术及适应性研究初报

本研究以中龄PR107和热研7-33-97橡胶树为研究对象,设割胶前1、2、3、4、5 d涂施乙烯利的5个刺激时间处理,比较不同处理的胶乳产量;以d4（4天1刀）割制为对照,中龄PR107和热研7-33-97分别设6个刺激强度的d6（6天1刀）割制处理,包括4个乙烯利浓度以及最高浓度下的3个涂药周期,比较分析不同处理的产量、胶乳生理及死皮病发生情况。结果表明：周期最后1刀的第2天或周期第1刀的前2~3 d进行涂施乙烯,刺激效果良好,可获得较好的胶乳产量。中龄PR107进行d6割胶的产胶潜力很难通过适度刺激挖掘出来,采用4%乙烯利,2~3刀周期涂药的刺激策略可获得相对较好的产量效应及生理效应。热研7-33-97对d6割制适应性较好,采用2~3刀周期涂施2.0%~2.5%乙烯利的低刺激强度技术措施,可获得了良好的产量,且胶乳生理参数反应良好。此外,d6割制的高产期单株刀次产占全年产量的3.0%~4.8%之间,确保高产期的割胶刀数是保证d6割制产量的关键。     

我国乙烯利刺激割胶的研究概况和初步设想

本文评述了我国15年来乙烯利刺激割胶的研究概况。在刺激剂的施用技术上,我国采用低浓度、低剂量刺激,并确定了芽接树(如PR107)的乙烯利刺激阈值为0.05％,浓度从0.05％逐渐增至10％,产量不断上升,为有效刺激至高效刺激范围;浓度超过10％,产量趋于下降,为可容忍刺激至有害刺激范围。我国普遍采用乙烯利糊剂,试验表明,这种剂型比水剂或油剂(或乳剂)为佳,是很有应用价值的新剂型。为了克服乙烯利的副作用,根据生理上的互补效应,我国开始施用乙烯利复方,以逐步取代乙烯利单方,现已发现几种乙烯利复方具有多方面的优点。在刺激割胶技术方面,我国根据刺激胶树重新建立生理平衡的观点,提出在我国植胶条件下施用乙烯利必须注意三方面的调节。首先是割面调节,包括采用缩短割线、低频割胶和轮换割面,以减轻割面的生理胁迫。其次是药量调节,我国普遍施用低浓度乙烯剂,以取代中、高浓度乙烯利刺激,取得了持续增产的良好效果。第三是营养调节,包括体内营养调节(采用产胶动态分析方法)和体外营养凋节(即增施肥料)。本文对刺激割胶树提出了只割高产原生皮,不割低产再生皮的初步设想。     

中龄PR107和热研7-33-97橡胶树“6天1刀”割制的刺激技术及适应性研究初报

本研究以中龄PR107和热研7-33-97橡胶树为研究对象,设割胶前1、2、3、4、5 d涂施乙烯利的5个刺激时间处理,比较不同处理的胶乳产量;以d4(4天1刀)割制为对照,中龄PR107和热研7-33-97分别设6个刺激强度的d6(6天1刀)割制处理,包括4个乙烯利浓度以及最高浓度下的3个涂药周期,比较分析不同处理的产量、胶乳生理及死皮病发生情况。结果表明:周期最后1刀的第2天或周期第1刀的前2～3d进行涂施乙烯,刺激效果良好,可获得较好的胶乳产量。中龄PR107进行d6割胶的产胶潜力很难通过适度刺激挖掘出来,采用4%乙烯利,2～3刀周期涂药的刺激策略可获得相对较好的产量效应及生理效应。热研7-33-97对d6割制适应性较好,采用2～3刀周期涂施2.0%～2.5%乙烯利的低刺激强度技术措施,可获得了良好的产量,且胶乳生理参数反应良好。此外,d6割制的高产期单株刀次产占全年产量的3.0%～4.8%之间,确保高产期的割胶刀数是保证d6割制产量的关键。     

热研7-33-97幼龄开割树对低频刺激割制的适应性研究初报

研究了速生高产优良无性系热研7-33-97在幼龄开割期对低频刺激割制的适应性。3a结果表明，该品种在幼龄开割期使用低频乙烯利刺激割胶表现出胶乳再生能力强、用于生长的干物质分配率高、排胶速度快等生理特性。采用低频、短线、少药等技术措施，有利于胶树的产胶与生长。     

化学刺激对抗寒胶树产量效应及其生理状况的研究

本文主要是探索在刺激条件下,对抗寒胶树低频割胶的可能性,供试材料为天任31—45。1979—1984年试验表明,每株次埋10克电石和涂0.2克乙烯利的胶树,采用s/2、d/3割制,改变了光合产物的分配率,提高了经济系数,干胶产量比常规刀割增产,经济效益显著;经五年刺激割胶后转为不刺激常规割胶,干胶产量仍然保持高产,而且干胶含量和茎围生长恢复也较快,每株次埋15克电石和涂0.3克乙烯利的胶树,副作用显著,转为不刺激常规割胶后,不仅产量低,而且干胶含量和茎围生长受到严重抑制,因此,从适当降低割胶强度,又尽量减少副作用考虑,初步认为,闽南地区抗寒无性系天任31—45胶树采用低剂量的电石与乙烯利综合刺激。年割30—40刀为宜。 统计分析表明,刺激强度和割胶强度与乳清含糖量和细胞质透性呈负相关,与叶片的细胞汁浓度和某些无机离子含量呈正相关。在一定范围内刺激剂量与产量和干胶分配率呈正相关,而与干含和茎围增长呈负相关。胶树经过五年刺激割胶后转为不施药常规割胶,结果表明,这些胶树的生长和产胶均正常,副作用不显著,因此,采用低强度刺激和低频率割胶,是提高寒害地区低产树产量的重要途径。     

橡胶树胶木兼优品种热垦525生理特性研究

研究橡胶树胶木兼优新品种热垦525的生理特性,为生产上设计新品种配套的割胶制度提供理论依据。本文采用了胶乳诊断法比较了热垦525与RRIM600、PR107胶乳产量和胶乳各项生理指标。结果表明,热垦525是一个排胶性能良好,代谢旺盛的高产品种,在生产中应适当控制割胶强度。     

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.     

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.     

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.     

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.     

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).     

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).     

Pharmacokinetics of Marine-Derived Drugs

Marine organisms represent an excellent source of innovative compounds that have the potential for the development of new drugs. The pharmacokinetics of marine drugs has attracted increasing interest in recent decades due to its effective and potential contribution to the selection of rational dosage recommendations and the optimal use of the therapeutic arsenal. In general, pharmacokinetics studies how drugs change after administration via the processes of absorption, distribution, metabolism, and excretion (ADME). This review provides a summary of the pharmacokinetics studies of marine-derived active compounds, with a particular focus on their ADME. The pharmacokinetics of compounds derived from algae, crustaceans, sea cucumber, fungus, sea urchins, sponges, mollusks, tunicate, and bryozoan is discussed, and the pharmacokinetics data in human experiments are analyzed. In-depth characterization using pharmacokinetics is useful for obtaining information for understanding the molecular basis of pharmacological activity, for correct doses and treatment schemes selection, and for more effective drug application. Thus, an increase in pharmacokinetic research on marine-derived compounds is expected in the near future.