海洋大型绿藻条浒苔与微藻三角褐指藻相生相克作用的研究

以种群密度为变量,采用实验生态学手段研究了大型海藻条浒苔与赤潮藻类三角褐指藻间的生长竞争关系,以及条浒苔水溶性抽提液对三角褐指藻生长的影响。结果表明,在无营养盐限制条件下,低密度条浒苔(0.3~0.7 g/L)均能抑制三角褐指藻(起始浓度104cell/ml)的生长,最大抑制率为74.5%;低起始浓度(102~103cell/ml)的三角褐指藻,对条浒苔具有促生长效应,而高起始浓度(104~105cell/ml)的三角褐指藻在一定程度上抑制条浒苔的生长。条浒苔水溶性抽提液(0.3~0.7 g/L)对三角褐指藻的生长皆表现出明显的抑制效应,平均抑制率为75.2%,抑制效果较条浒苔鲜组织更为明显;其最大抑制效应(84.8%)表现在接种后的第8天,三角褐指藻的生长抑制量随条浒苔水溶性抽提液浓度的增加而增大。表明条浒苔可能通过相生相克作用影响共培养体系中三角褐指藻的生长。     

In Vitro Activity of Lawsonia inermis （Henna） on Some Pathogenic Fungi

The present study was conducted to investigate antifungal activity ofLawsonia inermis （Henna plant）. Leaf samples of the plants were collected from Eastern Nile of Khartoum state, Sudan. Ethanol and petroleum ether extracts in various concentrations were obtained by maceration （cold method）. The extracts were bioassay in vitro to know their bioactivity to inhibit the growth of tested fungi. The cup plate agar diffusion method was adopted to assess the antifungal activity of the extracts against tested yeasts while agar incorporated method was used for other molds. Both extracts revealed anti fungal activity against all yeast strains except Pichiafabianii which was found resistant to both ethanol and ether extracts. The results displayed antifungal activity against tested fungi. Minimum mould concentration （MMC） of the extracts was determined. The obtained results revealed antifungal activity of henna leaves extracts which support the traditional use of the Henna in therapy of fungal infections. The possibility of therapeutic use of Sudanese henna as antifungal agents is recommended.     

Lethal and Sublethal Effects of Leaves Extracts from Native and Exotic Plants in Southern Brazil against Spodoptera frugiperda （Lepidoptera： Noctuidae） Caterpillars

The caterpillar Spodopterafrugiperda is an important pest of several crops, due to the damage it causes and the difficulty of its control. The method of controlling these pests is through chemical insecticides, which cause adverse effects to the biotic and abiotic environment. The selection of new insecticides that meet the requirements of efficacy, safety, selectivity and those are economically viable, is highlighting the study of mechanisms of plant defense. The present study aimed to verify the insecticide effect of 27 plants in three different types of plants extracts： aqueous, decoction and polypeptide on S. frugiperda. Three plants were chosen for performing sublethal effects bioassays： two plants with the highest corrected mortality （E. pulcherrima and R. simsii） and the other plant （Maytenus ilicifolia （espinheira santa）） with corrected mortality similar to control. In preliminaries bioassays, 25 plants showed corrected mortality less than 50%, according to Abbott＇s formula. R. simsii （azalea） and E. pulcherrima （billed parrot） showed 51% and 68% of corrected mortality, respectively. Only R. simsii aqueous and the three extracts of E. pulcherrima differ significantly from control （P 〈 0.05）. The aqueous extracts and decoction of R. simsii and polypeptide extract of E. pulcherrima reduced the larval period of S. frugiperda, different from control （P 〈 0.05）. The polypeptide extract of R. simsii reduced the pupal period of the target insect. The extracts obtained by decoction, aqueous and polypeptide of E. pulcherrima extracts and decoction of polypeptides and R. simsii affected the fertility and fecundity of S. frugiperda. For the other parameters, there is no significant difference when compared with the control. The results of this study suggest that the extracts obtained by decoction, aqueous and polypeptide of E. pulcherrima and R. simsii can be used to control S. frugiperda. However, the successful search, product starting from extracts of plants depends on the availability of plant and the entire assembly around the detection of bioactive products, in addition to the active ingredients of the chemical synthesis and elucidation of the target site insecticide molecule.     

紫茎泽兰水浸液对不同玉米品种的化感效应分析

利用生物检测法研究了不同采收时期紫茎泽兰的茎叶水浸液对不同品种玉米种子萌发和幼苗生长的影响。结果表明:不同受体品种对紫茎泽兰化感效应的敏感性存在差异,各品种敏感性(敏感指数M3)顺序为:云瑞1号(-0.086 5)白糯1号(-0.068 2)鲁三3号(-0.038 6)。紫茎泽兰水浸液化感效应大小与其浓度密切相关。12月份采收的紫茎泽兰,其茎叶水浸液对玉米的化感抑制作用随浓度增加而增强。而4月份采收的紫茎泽兰,其茎叶水浸液在低浓度(0.001 g/m L)时对各品种均有化感促进作用;中浓度(0.005 g/m L)时,对白糯1号、鲁三3号有促进作用,但对云瑞1号呈抑制作用;高浓度(0.025 g/m L)时,对所有供试玉米品种均表现为化感抑制效应,其中对鲁三3号的抑制作用最强。紫茎泽兰化感效应与其采收时期关系密切,4月份采收的紫茎泽兰,其茎叶水浸液表现出更强的化感抑制效应。     

金针菇提取液中麦角硫因氨基酸的功能及其在食品工业中的应用前景

麦角硫因氨基酸是金针菇提取液中富合的一种天然抗氧化物质,可作为食品抗氧化剂使用.然而,国内对麦角硫因氨基酸研究甚少.介绍了金针菇提取液中麦角硫因氨基酸的特性、检测方法及在食品工业中的应用前景,并提出其对生鲜肉类货架期的延长以及肉质的提高具有重要的意义.     

大蒜提取液对番茄的保鲜效果

为了延长番茄的贮藏时间,减少因腐烂变质造成的损失,以鲜番茄为原料,用不同浓度料液比大蒜提取液对番茄进行浸泡处理。以鲜番茄贮藏期的总糖含量、失重率、维生素 C 含量、腐烂指数和感官品质为测定指标,研究不同大蒜提取液对番茄的保鲜效果。结果表明：不同料液比的大蒜提取液均有保鲜作用,其保鲜效果由大到小顺序为1∶6＞1∶10＞1∶14＞1∶18。番茄在大蒜提取液料液比1∶6的条件下保鲜效果最好,可保鲜15 d。对照在第12天时失去食用价值,大蒜提取液料液比1∶6处理的番茄在12 d 时,总糖含量为9．5％,维生素 C 含量为77 mg/100g,比对照组分别高3．9％和16 mg/100g;失重率达2．6％,腐烂指数为9％,比对照组分别低2．8％和33％。     

柚皮粗提物对松梢螟幼虫生物活性影响研究

通过测定柚皮粗提物对松梢螟幼虫的拒食活性、生长发育影响和毒杀活性,研究其对松梢螟幼虫的室内毒力作用.结果显示:100 mg/mL的柚皮粗提物生物毒性最强,处理24、48 h后的松梢螟幼虫的拒食率分别达到了99.28％ 、94.23％,拒食中浓度AFC50分别为7.61、9.28 mg/mL;对松梢螟四龄幼虫的生长抑制率在处理后24、48、96 h分别为96.32％ 、95.44％和93.19％,LC50分别为9.56、13.52、8.38 mg/mL;三龄幼虫、五龄幼虫的校正死亡率分别为90.00％和80.00％,与对照药剂噻虫啉的效果处于同一显著水平.柚皮粗提物对三龄幼虫毒杀作用效果优于五龄幼虫,LD50分别为18.46、25.99 mg/mL.说明柚皮粗提物对松梢螟幼虫生物活性有一定影响.     

大棚番茄连续套蒜第3年作物生产和土壤养分分析

【目的】研究大棚番茄与大蒜(青蒜)连续套种3年对作物的生物效应和土壤养分含量的影响。【方法】2010-08-2011-07,在塑料大棚内以番茄单作为对照,设番茄套作大蒜和番茄套作青蒜2个处理,在秋茬番茄行间套种大蒜或青蒜,大蒜(青蒜)生长持续到春季,此时定植春茬番茄,分析比较不同模式连续种植第3年时的作物生物效应和土壤养分含量。【结果】与番茄单作相比,套蒜处理对秋茬番茄生长和产量有一定促进作用,并能显著提高其主要品质指标,但套蒜处理对春茬番茄生长和产量有显著的竞争性抑制作用。套作大蒜和青蒜对番茄根结线虫有一定抑制作用,其防病效果在秋茬番茄上分别为54.9%和60.0%,在春茬番茄上分别为34.3%和39.4%。套蒜处理可明显提高秋茬和春茬番茄土壤碱解氮和速效磷含量,但对土壤速效钾含量影响效果不同。不同套作模式的年产值不同,套作大蒜和青蒜处理分别较番茄单作增值11.0%和11.9%。【结论】连续套蒜可消减大棚番茄根结线虫病,提高年产值。     

基于图像处理与GUI的大蒜切脐的研究

本课题采用数字图像处理技术,通过研究适合于大蒜切脐定位的专用算法,通过GUI界面编程编写出大蒜切脐软件系统,实现对切脐位置的自动、精确定位。结果表明,该程序能够很好的将大蒜根须与蒜体区分,为大蒜切脐机械化的实现提供了技术支持。     

植物生态提取业中产品生态贸易的发展趋势

近几年，中国提取物产业发展迅速，中国植物提取物出口发展势头良好，年平均增幅在20％以上，出口持续快速增长。中国植物提取物进入国际市场存在的主要问题是在国与国之间在实际法规、技术标准、认证制度和检验制度等方面的差异形成的技术贸易壁垒和环境壁垒。通过生态技术途径突破贸易壁垒是中国植物提取物生态贸易的发展趋势。