耐除草剂转基因玉米对田间节肢动物群落多样性的影响

为了明确转基因耐草甘膦/草铵膦玉米C0010.1.1对大田节肢动物群落多样性的影响,2015年在田间隔离条件下,采用直接观察法和陷阱法对大田节肢动物群落进行统计,分析比较了节肢动物的功能群、多样性指数、优势集中性指数、均匀性指数等相关参数,并计算节肢动物群落的相似度。与非转基因对照玉米178和常规玉米先玉335相比,转基因玉米C0010.1.1田间节肢动物物种数、多样性指数、均匀性指数和优势集中性指数等指标随时间动态变化的趋势基本一致,没有显著差异。这表明转基因玉米C0010.1.1田间节肢动物群落结构与受体品系和常规种基本相似,与对照相比该转基因玉米对田间节肢动物群落的影响无显著差异。     

干旱绿洲区不同生长年限枸杞林地面节肢动物群落分布特征

选择干旱绿洲区宁夏中宁县1、3、5、8和10年生枸杞(Lycium barbarum)林为研究对象,以农田为对照,利用陷阱诱捕法调查不同样地地面节肢动物群落分布特征及其与环境因子间的关系。结果表明:(1)随着枸杞林生长年限增加,枸杞林地面节肢动物优势类群和稀有类群变化较小,而常见类群变化较大,其优势度和类群数分别在3、10年生枸杞林出现最大值;捕食性、植食性、杂食性和腐食性地面节肢动物个体数均呈现先增后减的趋势,最大值分别出现在8、3、3和8年生枸杞林。(2)随着枸杞林生长年限增加,地面节肢动物个体数和类群数均呈现先增后减的趋势,最大值分别出现在8和3年生枸杞林;Shannon-Wiener和Simpson指数在5和10年生枸杞林地显著降低。(3)RDA和偏RDA分析结果显示,植物高度、植物冠幅和土壤pH是影响枸杞林地面节肢动物群落分布的主要环境因素。研究表明,宁夏干旱绿洲区玉米田转化为枸杞林及在其生长过程中,地面节肢动物群落组成尤其是常见类群发生较大变化,以常见类群组成变化较大为主要特征。玉米田在转为枸杞林的过程中地面节肢动物个体数和类群数均降低,但3～8年生枸杞林具有较高的节肢动物多样性。     

水环境中微塑料表面细菌群落特征研究进展

微塑料因其比表面积大、难降解等特点,在水环境中长期存在,可作为水环境中微生物的独特栖息地。以细菌群落为主的微生物可定殖在微塑料表面,对生态系统和人类健康产生潜在风险。本文综述了国内外海水、淡水环境中微塑料表面细菌群落特征的研究进展,阐述了微塑料表面细菌群落的研究方法和结构多样性,分析了暴露时间、地点及塑料理化性质对微塑料表面细菌群落多样性的影响,探讨了水环境中微塑料表面细菌群落的生态效应和健康风险。后续研究应采用宏基因组学全面地探究水环境中的“微塑料圈”,并关注远洋、入海口和内陆地表水微塑料表面微生物群落,从全球尺度上探索水环境中微塑料表面微生物群落的定殖规律及其生态效应。此外,鉴于微塑料表面存在降解菌,需进一步明确定殖在微塑料表面的微生物参与微塑料降解的效率及其机制,可为了解微塑料在水环境中的归宿问题提供科学依据。     

森林-草原交错带土壤节肢动物的群落结构及其季节变化

对河北北部塞罕坝森林-草原交错区土壤节肢动物的群落结构特征及季节变化进行了调查.结果显示,交错区3个地带(森林带、森林-草甸带和草甸-草原带)土壤节肢动物群落的优势类群组成相似,均为蜱螨目和弹尾目,但不同生境中优势类群所占群落总数的比例不同,并且各样地常见类群和稀有类群的组成差异较大.3个地带土壤节肢动物群落类群数与DG多样性指数的季节变化总体表现为秋季多样性最高,夏季次之,春季最低,同时各样地土壤节肢动物群落因生境条件不同而形成各自的季节消长特点.3个地带土壤节肢动物群落类群数随着土层的加深而递减,具有明显的表聚性.     

钨尾矿生态恢复中桉树林地表节肢动物群落特征及影响因子研究

地表节肢动物对土壤重金属污染及生态恢复中的生境变化具有重要的指示作用,不同动物类群对植被恢复具有不同的响应,它们与植物一起调控了土壤的恢复过程。然而,目前对地表节肢动物类群对植被恢复的响应及其与植被和土壤环境变化的关系认识不足。以1 a桉树(Eucalyptus)林、7 a桉树林及26 a外围桉树林作为研究对象,以无污染桉树林为对照,基于4种样地土壤理化因子、重金属因子及地表节肢动物群落的调查统计数据,采用生态指数及冗余分析的方法,研究不同种植年限桉树林与外围桉树林生境地表节肢动物群落对土壤质量和重金属因子的响应机制。结果显示:种植7a的桉树林地表节肢动物个体数量(N)、丰富度(R)和多样性指数(H′)(N=131,R=2.026,H′=1.644)高于1 a桉树林(N=40,R=0.701,H′=0.617),但显著低于外围桉树林(N=823,R=2.345,H′=1.939),对照桉树林(N=1251,R=2.354,H′=1.947)显著高于其他样地。冗余分析表明,土壤理化因子与地表节肢动物群落呈显著正相关,土壤速效磷和有机质对地表节肢动物群落变化的贡献率最大,两个环境因子总共解释了89.67%的环境变异,速效磷对地表节肢动物群落的影响最大,贡献率达79.83%,是主要的影响因子,多样性指数随土壤质量的提升而增大。重金属因子与地表节肢动物群落呈显著负相关,Cu对地表节肢动物群落的影响最大,贡献率为88.95%,是主要的毒性因子,动物群落多样性指数随重金属(Cu、Ni、Zn)含量的增加而下降。研究表明:随着钨尾矿恢复区桉树种植年限的延长,土壤质量提升,生态恢复区植被迁入与群落演替促进了地表节肢动物群落食物网的形成,对地表节肢动物群落演变与多样性增加起到关键作用。     

外源降解菌对黄麻根区净化能力的生物强化作用

通过原生质体电融合得到经EGFP标记的外源细菌(蒽高效降解菌An和表面活性剂产生菌P)与黄麻根际优势菌融合的2株融合子Tu-An与融合子Tu-P,然后将两种融合子以及出发菌株分别定殖到播种了黄麻(Corchoruscapsulari)的蒽污染土壤中,对不同污染物浓度下的细菌定殖、植物生长及蒽降解做了初步研究.研究表明,在相同的初始接种量下,融合子的定殖数量明显高于出发菌株;在两种融合子共存的条件下,定殖数量也略高于单一融合子的定殖数量.在接种外源菌的土壤中,植物获得了更好的生长条件,得以良好生长;而没有投加降解菌的组别中,黄麻的生长明显受到了较严重的抑制.投加外源降解菌可以促进生物降解,达到生物强化的目的.实验研究说明,把外源降解菌投加到污染土壤中进行生物强化修复是可行的.图3表2参20     

林丹烟剂对毛竹林冠与林下层节肢动物共有种及其多样性的影响

共有种反映毗邻生境节肢动物群落的相互作用程度及其潜在互作途径的多样性.通过对施用林丹烟剂后毛竹林冠层与林下层节肢动物的系统定位调查,分析和比较了林丹烟剂干扰下两个林层的节肢动物共有种及其多样性.结果表明,以未防治和白僵菌防治为对照,施用林丹烟剂显著减少了林冠和林下层的共有种及其个体数,降低了两个林层中共有种的多样性;在物种方面主要表现为蜘蛛目、膜翅目、鞘翅目、双翅目和鳞翅目共有种减少;在个体方面,林下层主要表现为蜘蛛目、膜翅目、鞘翅目和双翅目共有种个体减少,林冠层主要表现为蜘蛛目、鞘翅目和双翅目共有种个体减少.但无论在物种还是个体方面,林丹烟剂对捕食性共有种的影响均最大.进一步的灰色关联分析表明,引起共有种多样性下降的主要原因在于共有物种的减少.因此认为,林丹烟剂干扰削弱了林下和林冠层节肢动物之间的相互作用,不利于林下生境促进林冠层生物多样性和增强群落对叶部害虫自然控制作用等生态功能的发挥.图1表6参22     

3株芽孢杆菌在水稻根际定殖促生及其在土壤中的存活

植物根际促生菌(PGPR)可分泌植物生长激素,促进土壤养分循环,是生物肥料重要的种质资源。PGPR吸附于作物根系是形成定殖与功能的必要条件,抗性药物标记是研究功能菌株定殖促生能力的一种手段。利用解钾功能菌(Bacillus aryabhattai LZP01,简称LZP01)、解磷功能菌(Bacillus pumilus LZP02,简称LZP02)和溶磷功能菌(Bacillus megaterium LZP03,简称LZP03)这3株高效的水稻根际促生菌,通过抗生素药物利福平梯度筛选分别得到标记菌株K-LZP01、K-LZP02和K-LZP03,并且研究标记菌株的功能保留情况,进而检测标记菌株在水稻根际与土壤中定殖存活及促生能力。结果表明,水稻幼根浸入菌液后吸附量随浸入时间的增加而增大,其中K-LZP01在10min后吸附基本稳定;K-LZP01在50 min时吸附量达到最大;K-LZP03在5 min时吸附量达到最大,最大吸附量为12×10~7CFU·g~(-1),之后趋于动态稳定。将水稻幼苗浸入不同浓度菌悬液中,幼根吸附量随菌悬液浓度的增大而增大。标记菌株在接种于土壤中10 d后定殖量趋于稳定,且定殖能力较强。距离水稻根际越近标记菌株含量越高,表明菌株定殖竞争力越强。在灭菌土与未灭菌土条件下,3株菌株均具有促进水稻根系生长的能力。     

荧光假单胞菌(Pseudomonas fluorescens)工程菌株田间残留和扩散的追踪检测

分别在北京和江苏省连云港市对携带Btcry基因的荧光假单胞菌工程菌进行了田间残留与扩散的追踪检测 .对越冬前后的试验地和保护地土壤样品进行抗生素抗性平板分离 ,能检测到极少量的具有与出发菌株相同抗性的荧光假单胞菌菌落 ,但没有发现工程菌株的残留与扩散 .对江苏试验地样品还进行了工程菌株质粒卡那霉素和壮观霉素抗性标记基因的抗性菌落分离 ,绝大多数样品中都能分离到包括荧光假单胞菌在内的抗性菌落 ,土样中菌密度n(cfu) =10 4 ～ 10 5g-1,但进行Btcry基因PCR -RFLP检测时没有从样品中得到特异扩增产物 .研究结果表明 :工程菌株抗性标记基因在自然界广泛存在 ,工程菌在株环境中没有残留和扩散 ,具有良好的生物安全性 .表 4参 8     

生物邻体和生境异质性共同驱动乔木幼苗存活动态

以长白山原始阔叶红松林样地为平台,样方中胸径小于1 cm的乔木幼苗为研究对象,基于2012-2014年连续3年的幼苗调查数据,利用广义线性混合模型分析影响群落乔木幼苗存活的生物邻体和生境异质性,探讨阔叶红松林幼苗存活影响因素及物种共存机制.结果显示:(1)生物邻体和生境异质性对幼苗存活都有显著影响,适宜大树生长的局域生境可能同样也适宜幼苗的存活,幼苗在林冠开阔度较高和土壤中含有较高有效氮、全磷和全钾的区域存活率较高.(2)幼苗个体之间存在明显的竞争,较多的幼苗邻体会显著降低幼苗的存活率.2年生幼苗存活分析中同种幼苗邻体与幼苗存活呈显著负相关,表明存在负密度制约效应.(3)随着存活年龄的增加,生境异质性对幼苗存活的影响逐渐增大.本研究验证了负密度制约效应和生境异质性对该温带森林乔木幼苗存活有着重要影响,各个因子的相对重要性随着种子传播方式、年龄级以及物种而发生变化,证明群落多样性维持和物种共存会随着个体发育过程的不同而变化.     

Tolerance of soil pathogens co-varies with shade tolerance across species of tropical tree seedlings

A negative feedback between local abundance and natural enemies could contribute to maintaining tree species diversity by constraining population growth of common species. Soil pathogens could be an important mechanism of such noncompetitive distance and density-dependent (NCDD) mortality, but susceptibility to local pathogens may be ameliorated by a life history strategy that favors survivorship. In a shade-house experiment (1% full sun), we tested seedling life span, growth, and mass allocation responses to microbial extract filtered from conspecific-cultured soil in 21 tree species that varied in abundance and shade tolerance in a wet tropical forest (La Selva Biological Station, Costa Rica). Forty-three percent of the species had significant reductions, and 10% of the species had significant increases in life span, growth, root length, or root surface area when inoculated with microbial extract; 10% of the species experienced opposing reductions and increases in these characteristics. Contrary to expectation, species' local abundance was not related to species-specific responses to microbial extracts from cultured soils. Across species, seedling shade tolerance (survival at 1% full sun) was negatively correlated with susceptibility to the microbial. treatment for both survival and total mass accumulation, thereby exaggerating shade tolerance differences among species. Thus, soil pathogens may contribute to species coexistence through heightening niche differentiation rather than through negative density dependence in common species.     

Soil and plant biodegradation of chlorpyrifos in fields of cauliflower and brussels sprouts crops

For the protection of early and summer cauliflower and brussels sprouts crops against root fly, the insecticide chlorpyrifos was applied at planting onto soil around the stem of the plant, or in the planting line. In the soil, chlorpyrifos (1) was transformed into the insecticide metabolites oxon, 0,0‐diethyl‐0‐(3,5,6‐tri‐chloro‐2‐pyridinyl) phosphate (2), and 3,5,6‐trichloro‐2‐pyridinol (3). The soil half life time of chlorpyrifos could be 2.8 times greater (42 days relative to 15 days) when the field history as to cauliflower monoculture and insecticide treatments was short (1 year), than when it was long (8 years). Rains and season also had cumulative effects on the chlorpyrifos soil half life times. In the leaves of cabbage, chlorpyrifos and compound 3 were observed at concentrations which were higher, especially when their soil concentrations were high. Chlorpyrifos and compounds 2 and 3 however were not detected in the “flower” of cauliflower, nor in the brussels sprouts itself, the limit of sensitivity being 0.02 ppm of fresh weight.     

热带砖红壤生长的小白菜吸收和累积PAHs的特征

为了了解和掌握热带土壤栽培的小白菜（Brassica rapa L. Chinensis Group.）对多环芳烃（PAHs）污染物的吸收和累积规律,为热带土壤的安全利用及农产品安全生产提供科学依据,于2013 年5-9 月在海南省农垦科学院海口试验站网室内进行了小白菜盆栽试验.各处理土壤分别施加3 种单体 PAHs 的质量分数梯度为0、0.4、0.8、1.6、3.2 mg·kg^-1,撒播小白菜种子出苗后,每盆留苗6 株,自然条件,常规管理,各处理小白菜培养30 d 后收获.小白菜和土壤样品,用超声水浴萃取,层析小柱净化后,利用气相色谱-质谱法测定样品中的3 种PAHs.结果表明,小白菜根和叶中3 种PAHs 累积量随土壤施加质量分数的升高而增加,根部和叶对Phe 最大累积量分别为86.25 ng·g^-1 和37.18 ng·g^-1,而对 BaP 的最大累积量分别为20.78 ng·g^-1 和3.56 ng·g^-1;小白菜根对Phe 与Fla 的生物富集系数较大,且二者无明显差异,但对 BaP 的生物富集系数较小,且差异显著（P=0.006）;3 种PAHs 单体在各种处理土壤中的残留在 84.49%-94.03%之间,各单体之间无明显差异,各处理之间也无明显差异.说明热带土壤生长的小白菜根和叶中3 种单体 PAHs 浓度显著低于其土壤中的浓度,且根部积累3 种单体PAHs 的浓度显著高于其叶中的浓度;小白菜叶对BaP 的吸收和累积量极少;小白菜根更易吸收和累积Phe 和Fla;小白菜生长30 d 后,绝大部分PAHs 仍残留在土壤中.     

Diversity of ground arthropod community at organic and chemically intensive tea plantation of Darjeeling terai

Tea in Darjeeling foothills and terai are grown conventionally, with application of chemical fertilizers and pesticides, as well as organically without these inputs. Ground level arthropod community was collected from the above two types of tea plots using pitfall traps. Catches from these environments showed variation in the arthropod faunal structure with numerically and taxonomically greater abundance in the organic than that of the conventional plot. Coleopterans were more diverse with largest number of families and Recognizable Taxonomic Units (or morphospecies) in the organic tea plot. The diversity and similarity indices for coleopterans were comparable, in organic and conventional tea plots at species and family levels. The close relationship of the indices suggested that diversity study at family level could be used as surrogate for species level diversity; thus alleviating the laborious and expertise job of taxonomic identification of arthropod species. Faunal diversity study at ground level gave the clue that soil of the organic plantation was healthier than that of the conventional tea plot.     

长春市不同土地利用生境土壤昆虫幼虫群落组成与生态分布

对长春市郊区天然次生林、市内公园风景林、郊区防护林和农田等土地利用生境进行土壤昆虫幼虫调查,研究土地利用差异对土壤昆虫幼虫群落特征的影响。研究区共捕获土壤昆虫幼虫35科411只,其中鞘翅目幼虫14科319只,双翅目幼虫13科64只,鳞翅目幼虫8科28只。研究结果表明:不同土地利用生境土壤昆虫幼虫群落组成与生态分布存在差异,防护林和农田土壤昆虫幼虫的类群数和个体密度显著减少;除农田外,其他生境土壤昆虫幼虫群落个体密度和类群数主要集中分布在0～5cm土壤层,生境凋落物的移除对土壤昆虫幼虫群落组成影响不明显;此外,鞘翅目、双翅目和鳞翅目幼虫对土地利用和植被类型变化的响应也不同。     

Additive effects of aboveground polyphagous herbivores and soil feedback in native and range-expanding exotic plants

Plant biomass and plant abundance can be controlled by aboveground and belowground natural enemies. However, little is known about how the aboveground and belowground enemy effects may add up. We exposed 15 plant species to aboveground polyphagous insect herbivores and feedback effects from the soil community alone, as well as in combination. We envisaged three possibilities: additive, synergistic, or antagonistic effects of the aboveground and belowground enemies on plant biomass. In our analysis, we included native and phylogenetically related range-expanding exotic plant species, because exotic plants on average are less sensitive to aboveground herbivores and soil feedback than related natives. Thus, we examined if lower sensitivity of exotic plant species to enemies also alters aboveground-belowground interactions. In a greenhouse experiment, we exposed six exotic and nine native plant species to feedback from their own soil communities, aboveground herbivory by polyphagous insects, or a combination of soil feedback and aboveground insects and compared shoot and root biomass to control plants without aboveground and belowground enemies. We observed that for both native and range-expanding exotic plant species effects of insect herbivory aboveground and soil feedback added up linearly, instead of enforcing or counteracting each other. However, there was no correlation between the strength of aboveground herbivory and soil feedback. We conclude that effects of polyphagous aboveground herbivorous insects and soil feedback add up both in the case of native and related range-expanding exotic plant species, but that aboveground herbivory effects may not necessarily predict the strengths of soil feedback effects.     

谷子根系对群体压力胁迫的生物学响应

采用根管土柱栽培的方法,比较了在相同根管土柱体积上种植不同株数谷子时谷子根系的主要特征,如根系数量,根系入土最大深度,根系SOD、POD活性,总根长,根系MDA含量及根系总吸收面积与活性吸收面积等对群体密度变化的可塑性.结果表明,不同群体下,谷子单株根数前期差异小,中后期差异大;而单位土体中的根量前期差异大,后期差异小.群体大(密度高),谷子根量、总根长及根系总吸收面积与活性吸收面积达到高峰的时间早,但衰亡时期也早,且入土深度较浅.群体小根量高峰出现得迟但维持的时间较长,根系在土体中的延伸深度也较大,有利于后期营养的获取和产量的提高.群体在作物生长中起着量的决定作用,而个体生长发育由于群体不同而引起质的差异.在生产上要想获得理想的产量,既要有足够量的保证,又要求达到一定质的标准,以使群体与个体协调发展.表4图2参18     

Rutabaga roots, a rich source of oviposition stimulants for the cabbage root fly

Summary. Two recently identified compounds ("CIFs"), present on the leaf surface of Brassica oleracea (cabbage), are the strongest oviposition stimulants known for the cabbage root fly, Delia radicum. Cabbage leaves contain these compounds in extremely low concentrations, and the amount of CIFs obtained from purifying leaf extracts was so small that it limited further research. We were able to purify far more of these two compounds from the roots of Brassica napus var. napobrassica (rutabaga). Apart from being a richer source of CIFs, rutabaga roots are considerably easier to collect and process than leaves. In addition, we isolated and identified a new CIF compound from the roots that is also very active in stimulating oviposition in the cabbage root fly. Received 26 May 2000; accepted 26 July 2000     

硫代硫酸铵添加对黄平大黄油菜富集土壤汞的影响-田间试验

在田间条件下,研究添加硫代硫酸铵对黄平大黄油菜(Brassica juncea var.HPDH)富集土壤汞(总汞含量13.7mg·kg-1)及土壤汞形态转化影响。试验设置2个处理,对照小区(无硫代硫酸铵)和处理小区(每公斤土壤加入8 g硫代硫酸铵),硫代硫酸铵溶液在植物收获前7 d添加到土壤。试验结束后,分析植物生物量和组织内汞含量。结果表明,硫代硫酸铵处理小区植物生物量(干重)要略高于对照区。硫代硫酸铵处理小区植物根系和地上部分汞含量分别是对照区的600和250倍。利用连续化学浸提法分析了修复前后土壤汞形态变化特征,发现硫代硫酸铵辅助植物修复后能显著降低土壤有机结合态汞含量,大幅度提高残渣态汞含量,溶解态与可交换态汞含量略有增加,特殊吸附态和铁锰氧化态汞含量无显著变化。     

Characteristics of soil micro-and macro-arthropods and soil properties in Songnen Grassland of China during different periods of freeze–thaw season

ABSTRACT

Soil properties have an important influence on soil fauna in the grassland ecosystem. However, the relationship between the structural characteristics of soil fauna and properties in the grassland ecosystem in freeze–thaw season remains unclear. Hence, the feature of soil arthropods and properties in Songnen Grassland of China were investigated in fall–winter alternating (T1), completely frozen (T2) and winter–spring alternating periods (T3) during freeze–thaw season in three years. Results showed slight differences in the community composition of soil animals with Oribatida, Prostigmata and Mesostigmata as co-dominant groups in all sampling periods. The total number of individuals of soil arthropod at low temperature was low. The pH value, electrical conductivity (EC), and moisture content had the same order of T3?>?T2?>?T1. The activities of invertase and urease increased with increasing soil temperature, whereas protease activity had no relationship with soil temperature, soil moisture, EC and soil organic matter (SOM), activities of protease and urease were principal factors affecting individual abundance of soil animals. The sequence of their effect degrees was moisture content > EC > SOM > protease activity > urease activity. The changes in the quantitative characteristics of soil animals were related to soil properties. Therefore, soil properties can affect the structural characteristics of soil arthropod in the Songnen Grassland of China in the freeze–thaw season.