新农药单甲脒在植物－土壤系统中的生态效应（以棉花为例）

该文研究了新农药单甲脒对植物－土壤系统的生态影响,结果认为：所设置的６个浓度（对照,２５％单甲脒水剂稀释１５００倍、１０００倍、８００倍、５００倍、１００倍）对棉花虫害有不同程度的防治效果,以１００倍最好,可防治棉花多种虫害。单甲脒对棉花种群的结构与功能无不良影响。高浓度单甲脒２２ ８００倍起至５００倍可使叶片气孔缩小,减少蒸腾速率,从而降低对水分的消耗,促进光合产物的形成,因而光合速率增长,生物     

单甲脒降解菌的分离筛选

从土壤、水体和受单甲脒长期污染的样品中通过富集培养,从中分离筛选到一株单甲脒耐性较高的ＤＲ－８菌株。该菌株在牛肉汁培养基中对单甲脒的耐性可达１２５０ｍｇ／Ｌ,而在无机盐培养基中的耐性则为５００ｍｇ／Ｌ。该菌株可以利用单甲脒作为唯一氮源,但是不能以单甲脒作为碳源和能源而生长。降解单甲脒的最适温度为３７℃,最适ｐＨ为７．０,其完整细胞悬液对５５０ｍｇ／Ｌ左右单甲脒的降解率最高可达６４．８２％。经鉴定该菌株为门多萨假单胞菌（ＰｓｅｕｄｏｍｏｎａｓｍｅｎｄｏｃｉｎａＤＲ－８）。     

石油烃降解物对Cd在土壤－植物系统中迁移转化影响的研究

研究棕榈酸、儿茶酚和香草酸对土壤中Ｃｄ行为的影响表明,土壤中儿茶酚对水稻的毒害浓度为１００ｍｇ·ｋｇ－１,而香草酸则为５００ｍｇ·ｋｇ－１．当土壤中儿茶酚为５０００ｍｇ·ｋｇ－１时,水稻籽实中Ｃｄ浓度降到０．００８ｍｇ·ｋｇ－１,土壤淋溶液中Ｃｄ浓度降为０．００５ｍｇ·Ｌ－１,３种有机物均能增加土壤中有机结合态Ｃｄ的比例,５０００ｍｇ·ｋｇ－１的儿茶酚处理,土壤中有机质结合态Ｃｄ占总Ｃｄ的４８．７１％．     

单甲脒农药对模型池塘生态系统群落结构的影响

在３ｍ×１ｍ×１ｍ（Ｖ＝３ｍ３）含有底泥的模型池塘生态系统中研究单脒农药对水生生物群落结构的影晌。规定实验浓度力０、１．５、３．０、６．０和１２．０ｍｇ／Ｌ,每１５ｄ加入１次２５％单甲脒农药水剂,连续加入４次,实验进行２个多月。在实验浓度范围内,童甲脒农药对水生生物群落产生不同程度的影响。浮游生物比较敏感：加药后头几天内,种类、数量及多样性指数下降,浓度越大,影响越明显;大约１周以后,各处理组浮游生物群落逐步得到恢复,实验后期其数量甚至可超过对照水平,但群落结构发生改变,敏感种类少或消失,耐污种类增加,生物多样性降低。底栖生物比较耐污：处理槽大型水生植物的叶绿素含量有所减少,但其种类和生物量未见明显差异;底栖动物种类、数量也未见明显变化。微生物最耐污,在处理槽水层及沉积物中好氧异养菌数量有所增加,沉积物中厌气菌数量也有增加的趋势。青鱼对单甲脒农药较敏感,在１．５ｍｇ／Ｌ以下浓度尚能正常存活和繁殖。单甲脒农药水剂明显增加水体氮、磷含量,尤其磷酸盐含量高,使水体氮、磷比例失调,可能导致水体富营养化。根据综合指标分析,在规定单甲脒盆酸盐浓度＜１．５ｍｇ／Ｌ的实验条件下,水生生物群落结构未见明显改变．     

胡杨离体器官发生及试管无性系的建立

研究了离体条件下胡杨（Ｐｏｐｕｌｕｓ　ｅｕｐｈｒａｔｉｃａ　Ｏｌｉｖｅｒ）茎段、叶片及愈伤组织的器官发生和植株再生技术。离体培养以ＭＳ为基本培养基并附加４０ｍｇ／Ｌ腺嘌呤和５００ｍｇ／Ｌ水解乳蛋白。离体叶片和茎段在ＢＡ为０．５ｍｇ／Ｌ和ＮＡＡ为０．５ｍｇ／Ｌ的培养基上诱导产生愈伤组织,并在含０．２５ｍｇ／ＬＢＡ和０．５ｍｇ／ＬＮＡＡ的培养基上继代增殖。ＢＡ为０．５ｍｇ／Ｌ和ＮＡＡ为０．１ｍｇ／Ｌ可诱导叶片和愈伤组织发生不定芽,诱导频率分别为１００％和８２．９％,对于茎段,ＢＡ和ＮＡＡ分别为０．１ｍｇ／Ｌ和０．０１ｍｇ／Ｌ时诱导不定芽频率可达８３％。试管苗在大量元素减半并附加０．０１５ｍｇ／ＬＮＡＡ的ＭＳ培养基上诱导生根,生根率达８６．２％。     

毒死蜱对家白蚁毒杀作用的时间与剂量效应

用含不同毒死蜱浓度的毒土对家白蚁（Ｃｏｐｔｏｔｅｒｎｅｓ ｆｏｕｍｏｓａｍｕｓ Ｓｈｉｒａｋｉ）进行了生物测定,浓度范围为０．０１５－０．４８ｍｇ／ｋｇ。观察２周。实验观察发现土壤中毒死蜱浓度为０．４８－０．０６ｍｇ／ｋｇ时,白蚁接触毒土出现的死亡高峰为４小时至２天;在０．０３ｍｇ／ｋｇ时,死亡高峰在１周以后;而浓度为０．０１５ｍｇ／ｋｇ时,２周内仍观察不到白蚁死亡。所获的生物测定数据很好地拟合时     

氟化氢对植物叶片中SOD酶活力和MDA含量的影响

本文研究了浓度为０．０４１ｍｇ／ｍ￣３，０．０８３ｍｇ／ｍ￣３和０．１６６ｍｇ／ｍ￣３的ＨＦ气体分别对小麦、玉米和蚕豆三种植物熏气后，植物叶片中ＳＯＤ酶活力的变化及膜脂过氧化产物ＭＤＡ含量的变化，实验结果表明高深度ＨＦ（０．１６６ｍｇ／ｍ￣３）对ＳＯＤ有抵制作用，较低浓度（０．０８３ｍｇ／ｍ￣３，０．０４１ｍｇ／ｍ￣３）下是先升后抑。在三种浓度下，叶片中ＭＤＡ含量均随熏气时间的延长而增加。三种植物对氟化氢的敏感性不同，由大到小依次为蚕豆、小麦、玉米。     

药用植物北五味子的组织培养

取北五味子带腋物嫩茎作为植体,培养于附加同种类和浓度激素的ＭＳ培养基上,在附国加６－ＢＡ２．０＋ＺＴ０．１ｍｇ／Ｌ时,诱导芽的效果最佳;在附加６～ＢＡ２．０＋ＮＡＡ０．２＋ＺＴ０．１ｍｇ／Ｌ时,芽的增殖率最好,在附加ＮＡＡ０．２ｍｇ／Ｌ时,生根效果最佳,当苗高２．０～２．５ｃｍ根数达３－５条时,开瓶锻炼２天,移栽于消过毒的土壤中,１０天后,成活率达１００％。     

呋喃那斯对暴发性鱼病的防治方法研究

呋喃那斯对暴发性鱼病的ＢＳＫ－１０菌株的最低抑制浓度为０．０１９ｍｇ／Ｌ,比呋喃唑酮的用量低３２倍。用０．２和０．５ｍｇ／Ｌ浸泡药浴病鱼的治愈率为９０％和１００％;５０ｍｇ／Ｌ呋喃唑酮的治愈率为０。１０ｍｇ／Ｌ和２０ｍｇ／Ｌ药浴１０分种的死鱼时间比５０ｍｇ／Ｌ呋喃唑酮迟１天。以０．５和４．０μｇ／ｇ腹腔注射给药的防治效果也优于同剂量的呋喃唑酮。对鲢以１００ｍｇ／Ｌ药浴２小时或白鲫ｉｐ６００ｍｇ／ｋ     

低分子量硫酸葡聚糖对小鼠造血干细胞动员作用的研究

给小鼠静脉注射低分子量（＜１０￣４ｕ）硫酸葡聚糖（ＤＳ）１５ｍｇ／ｋｇ后外周血中白细胞、单个核细胞（ｍｏｎｏｎｕｃｌｅａｒｃｅｋ,ＭＮＣ）、ＣＦＵ－ＧＭ、ＢＦＵ－Ｅ和ＣＦＵ－Ｍｉｘ产率等指标出现时相性变化。给药后１ｈ开始升高,２ｈ达到高峰、分别为药前值的２．２、２．６、３．８、４．４和３．０倍,７ｈ时趋向正常。给药后２ｈ上述各类细胞在外周血中的含量随着ＤＳ的剂量增加而增加。白细胞、ＭＮＣ计数在ＤＳ１８０ｍｇ／ｋｇ时达到峰值,均为对照组的４倍。２４０ｍｇ／ｋ８时未见明显增加。不同剂量ＤＳ对各系祖细胞均有不同程度的动员作用,ＤＳ剂量１５－３０ｍｇ／ｋｇ效果最好,每升血中ＣＦＵ－ＧＭ、ＢＦＵ－Ｅ、ＣＦＵ－Ｍｉｘ的数量分别相当于对照组的５．０、１１．９和８．８倍。其峰值出现时间与白细胞、ＭＮＣ不同,表明ＤＳ对不同类型细胞的作用机制也不尽一致。经口给小鼠投以ＤＳ２４０和４８ｏｍｇ／ｋｇ后,未见外周血中白细胞、ＭＮＣ计数有显著性升高,提示对造血干细胞没有动员作用。     

盐碱旱地转基因抗虫棉田昆虫群落多样性

棉花是耐干旱和耐盐碱的经济作物。随着土壤的盐碱化和干旱化, 在人口数量和植棉成本剧增的背景下, 我国黄河流域和长江流域棉花种植面积锐减, 棉花种植被迫向滨海盐碱地和内陆及西北干旱地区转移。本文于2013年和2014年在山东东营滨海盐碱地和河北枣强半干旱轻度盐碱地以非转基因棉(‘中棉所49’)为对照, 以转Bt基因棉(‘中棉所79’)为试验材料, 分别作施农药和不施农药处理, 于每年5月初到9月中旬, 调查取样点棉株及地面上害虫及其天敌的种类和数量, 并分析不同施药处理下转基因和非转基因棉田昆虫群落的生物多样性参数差异。结果表明, 施药和不施药转Bt基因棉田昆虫群落和害虫亚群落昆虫的个体总数均低于非转基因棉田, 其中昆虫群落和害虫亚群落个体数在二者之间差异显著; 转Bt基因棉田昆虫群落和害虫亚群落昆虫的多样性指数和均匀度指数均高于非转基因棉田, 而优势集中性指数均低于非转基因棉田, 但差异均不显著。施药条件下两种棉田的昆虫群落和害虫亚群落昆虫个体总数、多样性指数和均匀度指数均低于不施药棉田, 优势集中性指数均高于不施药棉田, 但转基因棉田和非转基因棉田之间无显著差异。表明转基因抗虫棉在盐碱旱地对棉田靶标害虫具有较好的控制作用, 棉田昆虫群落稳定性较高, 昆虫群落对外界的入侵和干扰缓冲能力强, 而化学农药的使用对昆虫群落杀伤力较大, 容易导致某种昆虫的抗性产生和昆虫群落的不稳定, 但比非盐碱旱地棉田昆虫群落生物多样性低, 棉田生态系统更简单。     

Soil Nitrogen Fertilization Effects on Phytoextraction of Cadmium and Lead by Tobacco (Nicotiana tabacum L.)

A greenhouse experiment using 24 plastic pots filled with 6 kg of Pb- and Cd-contaminated soil was carried out. In all 24 pots, soils were heavy metal–contaminated with 10 mg Cd kg^?1 soil and 500 mg of Pb kg^?1 soil by using CdCl and PbNO₃. Two-month-old tobacco (Nicotiana tabacum L.) plants were used to extract these heavy metals. Results showed that tobacco is able to remove Cd and Pb from contaminated soils and concentrate them in its harvestable part, that is, it could be very useful in phytoextraction of these heavy metals. Increasing additions of ammonium nitrate to soil (50, 100, and 150 mg N kg^?1 soil) significantly (p ≤ .05) increased aboveground Cd and Pb accumulation during a 50-day experimental period, whereas increasing additions of urea to soil (50 and 100 mg N kg^?1 soil) did not show these effects at the same significance levels. Increasing additions of ammonium nitrate to soil shows as dry matter increases, both accumulated Cd and accumulated Pb also increase when tobacco plants are growing under Pb- and Cd-contaminated soil conditions. Higher Pb concentrations depress Cd/Pb ratios for concentrations and accumulations, suggesting that Pb negatively affects Cd concentration and/or accumulation.     

异丙甲草胺及其高效体对我国南方潮土微生物的影响Ⅰ-过氧化氢酶

研究了0、5、20和100 mg·kg^-1浓度的异丙甲草胺及其高效体对土壤过氧化氢酶活性的影响.结果表明,不同浓度的异丙甲草胺处理对过氧化氢酶活性的影响不同,20 mg·kg^-1处理的土壤过氧化氢酶受到激活的程度最大,且一直处于激活状态,5 mg·kg^-1处理的土壤过氧化氢酶在前期受到抑制,后期则100 mg·kg^-1处理的土壤过氧化氢酶受激活较强.不同浓度的金都尔对供试土壤过氧化氢酶活性的影响表现为先激活、后抑制、再激活,并且后期100 mg·kg^-1处理的激活程度最大;5 mg·kg^-1和100 mg·kg^-1处理的异丙甲草胺对供试土壤生态环境的影响和危害可能大于金都尔,但20 mg·kg^-1处理则表现出例外.     

Kaolin potential for the integrated management of Aphis gossypii Glov. (Homoptera: Aphididae) on cotton

Kaolin-based particle film has been developed in the United States for use in agriculture as crop protectant. This work is aimed to determine the optimal kaolin concentration for use against Aphis gossypii, the most damaging sucking insect of cotton in Benin, West Africa. Following kaolin concentrations have been tested in four different experiments: 2%, 3%, 4%, 5%, 6% and 8%. The effect of kaolin is tested by recording the population dynamics of A. gossypii on cotton after spraying. Results showed that the solution containing 5% of kaolin has significantly reduced aphids' number. This concentration corresponds to a maximum of 18 kg of kaolin per hectare for the entire season when ultra low volume sprayer is used. Higher kaolin concentrations have left a large deposit of kaolin particle on cotton leaves thus handicapping chlorophyll synthesis and the proper growth and development of the plants. To obtain encouraging results, an adequate application method that provides a full and continuous coverage of the plants with kaolin particle film should be used. We suggest conducting trials on this product in practical cotton production conditions in West Africa to assess its potentiality as integrated pest management (IPM) component.     

Screen of Chinese Weed Species for Cadmium Tolerance and Accumulation Characteristics

The cadmium (Cd) tolerance and metal-accumulation characteristics of 29 species (18 families) of weed were studied by using outdoor pot-culture experiments. The results of this screening showed that Bidens pilosa and Kalimeris integrifolia (both Asteraceae) expressed some properties that are characteristic of Cd hyperaccumulators. In 10 mg/kg Cd-spiked soil, they accumulated a good deal of Cd in shoots (28 and 25 mg/kg DW, respectively) with high Cd enrichment factors (EFs; concentration in plant/soil). Cd accumulations in shoots were greater than those in roots (translocation factor (TF) >1, concentration in shoot/root) and the shoot biomasses did not decreased significantly compared to the unspiked control. The other weed species showed little accumulation of Cd, Pb, Cu, or Zn. In a concentration-gradient experiment, the Cd accumulation potentials of B. pilosa and K. integrifolia were examined further. Cd concentrations in leaves of B. pilosa growing in soils spiked with 25, 50, and 100 mg/kg Cd were up to 145, 160, and 192 mg/kg, respectively, and the Cd content in stems in the 100 mg/kg Cd-spiked soil was 115 mg/kg, all greater than the 100 mg/kg notional criterion for Cd hyperaccumulation. The Cd EFs and TFs were all greater than 1. The shoot biomasses did not decrease significantly compared to the controls. B. pilosa was thus shown to have some characteristics of a true Cd hyperaccumulator plant.     

转Bt基因抗虫棉的生态风险及治理对策

评述了转Bt基因抗虫棉的生态风险及治理对策。其生态风险主要表现在目标害虫的抗性和对非目标生物群落的变化。目标害虫与转基因抗虫棉的互相作用和抗虫棉杀虫毒素的时空表达方式是目标害虫抗性发展的主要途径。在转基因抗虫棉田中,虽然对目标害虫的防治次数大为减少,但害虫和天敌群落的稳定性仍不如常规棉田,某种次要害虫大发生的可能性较大。认为将转基因抗虫棉纳入综合防治体系并培育更加高效的抗虫棉是治理目标害虫抗性和防止次要害虫上升的重要措施。     

施用磷对王桉 (Eucalyptus regnans F. Muell.)幼苗生长及其氨基酸组

王桉 (Eucalyptus regnans F. Muell.) 是澳大利亚桉树中最重要的商业用材和人工造林树种之一.研究王桉的施肥与其体内氨基酸的积累和转化及与食叶虫害之间的相关性具有重要的经济和生态意义.在温室内利用2种不同来源的土壤对王桉幼苗进行了不同磷施用量(100 kg hm~(-2)和 200 kg hm~(-2))处理.结果显示,不同土壤和不同磷施用量对苗木生长影响显著,但均未显著影响苗木各部分的氮和磷含量水平.苗木木质部渗出液中的氨基酸含量以谷氨酰胺为主,并与苗木生长和磷施用量呈反相关.不同土壤和磷施用量对苗木组织中游离氨基酸组分和含量的影响不显著,但游离氨基酸的组分和相对水平随叶龄变化明显,尤其是精氨酸在嫩叶氨基酸总量中只占2%～3%,但在老叶中占到20%多;精氨酸在老叶中的积累极有可能是某些蛋白质降解而精氨酸即时合成所致,因为精氨酸一般不在韧皮部转运.谷氨酰胺在树液中含量最高并与苗木生长呈反相关或许可以作为预测桉树发生食叶昆虫危害的一个有用指标.     

The application of ethephon (an ethylene releaser) increases growth, photosynthesis and nitrogen accumulation in mustard (Brassica juncea L.) under high nitrogen levels

Ethephon (2-chloroethyl phosphonic acid), an ethylene-releasing compound, influences growth and photosynthesis of mustard (Brassica juncea L. Czern & Coss.). We show the effect of nitrogen availability on ethylene evolution and how this affects growth, photosynthesis and nitrogen accumulation. Ethylene evolution in the control with low N (100 mg N kg(-1) soil) was two-times higher than with high N (200 mg N kg(-1) soil). The application of 100-400 microl x l(-1) ethephon post-flowering, i.e. 60 days after sowing, on plants receiving low or high N further increased ethylene evolution. Leaf area, relative growth rate (RGR), photosynthesis, leaf nitrate reductase (NR) activity and leaf N reached a maximum with application of 200 microl x l(-1) ethephon and high N. The results suggest that the application of ethephon influences growth, photosynthesis and N accumulation, depending on the amount of nitrogen in the soil.     

应对全球气候变化的昆虫学研究

大气二氧化碳浓度升高、温度上升、降雨分布不均、灾害性天气出现频次增加等全球气候变化,深刻改变着农林生态系统昆虫群落的组成结构、功能和演替,使昆虫分布区域扩大、发生世代增多、生态适应性变异,从而影响了原有的植物-害虫-天敌间内在联系和各营养层间的固有平衡格局,最终导致一些害虫暴发成灾,一些昆虫种群数量下降,甚至一些昆虫物...