接种降解菌对土壤中邻苯二甲酸二异辛酯降解的影响

邻苯二甲酸二异辛酯〔Di-(2-Ethylhexyl)phthalate,DEHP〕是农田土壤中常被检出的有毒有机污染物,在土壤中有较长的持留性,微生物降解是其从土壤中消失的主要途径.本文采用温室盆栽试验研究了接种两株从污水处理厂活性污泥中分离得到的高效DEHP降解菌及其混合菌悬液降解土壤中DEHP污染的效果,以及土壤中添加葡萄糖和种植作物对其降解效率的影响.结果表明,在土壤初始DEHP浓度为100mg kg-1的条件下,接种两种降解菌及其混合菌悬液都可显著提高土壤中DEHP消失的速率,其残留半衰期比不接种对照缩短了32~48d,但在相同条件下接种不同降解菌的处理之间没有显著差异.土壤中添加0.6%的葡萄糖虽然可以强烈地促进土壤微生物的整体活性,但并没有提高修复效率,反而在短期内延缓了降解菌对DEHP的降解,延长了DEHP在土壤中持留的半衰期;植物生长可显著提高降解菌的降解效率,降低土壤中DEHP的残留浓度.研究结果同时也表明,只添加葡萄糖或只种植植物对土壤中DEHP的降解并没有显著的影响.图3表4参14     

炼焦污水零排放技术初探

本文介绍了炼焦污水零排小试结果,试验中采用新型大孔吸附树脂脱酚,蒸汽汽提脱氨,处理后的污水用作熄焦补充水.试验证明该零排放方案是可行的.     

The geographical distribution of plant latex

Summary Latex is a widespread defence in plants against natural enemies and a literature-based summary of latex-producing angiosperms shows records in 40 families, and more than 20,000 species are estimated to bear laticiferous structures of some kind. This is considerably higher than the usually quoted figure of 12,500 species. There are more tropical than temperate latex-bearing families, both in absolute numbers and proportionally. Proportions of latex-bearing families are similar both in tropical and in more widespread or cosmopolitan families. Significantly more latex-bearing species belong to tropical than either to temperate or to widespread taxa, both in absolute and in relative terms. These differences may be related to the higher diversity of natural enemy species and to higher rates of herbivory in the tropics.     

国家濒危植物永瓣藤分布的土壤环境特征

永瓣藤(Monimopetalum chinense)是卫矛科(Celastraceae)的一个中国特有单型属植物,被列为国家二级稀有濒危保护物种。本文对永瓣藤分布区14个样地土壤样品的pH值、有机质、全氮、水解氮、硝态氮、全磷、速效磷和全钾进行了检测分析,以期弄清该物种分布与土壤环境因子的关系。结果表明,其pH值的变化幅度为4.55～5.57,主要处于强酸性范围,适应幅度较窄。有机质与氮素非常丰富,相互间具有明显的相关性,有利于永瓣藤的生长与繁衍,但土壤中磷、钾素较为缺乏。土壤酸碱度和有机质的质量分数在某种程度上对永瓣藤的分布范围具有制约作用。     

珍稀濒危植物金花茶地理分布与生境调查研究

为了对珍稀濒危植物金花茶(Camellia nitidissima)进行有效保护,通过实地调查和相关资料分析,对其地理分布与生境进行了系统的调查研究。调查结果表明:(1)金花茶主要分布在广西西南部的防城、南宁、隆安、扶绥等县(市)。位于北纬21°30′～22°55′,东经107°36′～108°33′区域内。金花茶的垂直分布高度在12～450m之间,以海拔200～300m之间的范围较为常见。(2)金花茶为喜暖热植物,对热量要求较高,属热带性树种。金花茶不能忍耐阳光直射,为喜荫耐荫植物,要求的光合有效辐射一般小于photons12.8μmol?m-2?s-1。(3)金花茶群落植物组成种类多样,且多属热带性树种。组成群落主要科有橄榄科(Burseraceae)、山榄科(Sapotaceae)、大戟科(Euphorbiaceae)、桑科(Moraceae)、藤黄科(Guttiferae)、无患子科(Sapindaceae)、番荔枝科(Annonaceae)、梧桐科(Sterculiaceae)的种类。研究结果摸清了金花茶的地理分布和主要生态特性,为金花茶的引种驯化和种质资源的保存提供科学依据。     

Emission of oilseed rape volatiles after pollen beetle infestation; behavioural and electrophysiological responses in the parasitoid <Emphasis Type="Italic">Phradis morionellus</Emphasis>

Summary. The pollen beetle, Meligethes aeneus, is an important pest of oilseed rape, Brassica napus. Larvae of this species feed only in the buds and flowers of Brassicaceae. One important natural enemy of this beetle is the parasitoid Phradis morionellus that attacks larvae in buds and flowers and also feeds on the flowers. The preferences for odours of non-infested and infested rape were tested for both starved and fed parasitoids in Y-tube olfactometer experiments. The volatile blend released from pollen beetle-infested and non-infested flowering rape and from pollen beetle larvae was identified and quantified. Gas chromatography-electroantennodetection analyses were performed with female P. morionellus. Parasitoids in both treatment groups preferred infested rape, but the proportion of responding female P. morionellus was significantly lower for the group that was starved. Six of the 20 volatiles identified were released at higher rates from infested rape than from non-infested. None of these compounds was found in pollen beetle larvae headspace. P. morionellus antennae detected both major and minor components in the volatile blend. The volatiles released at a significantly higher rate from infested rape and detected by P. morionellus antennae were (Z)-3-hexenylacetate, (Z)-3-hexenol, 3-butenyl isothiocyanate and (E,E)-α-farnesene.     

不同有机物料在潮棕壤中有机碳分解进程

用尼龙网袋法研究了特定年度中，不同月份间有机物料在潮棕壤旱田、水田中有机碳分解速率及C／N变化。结果表明，4种物料(玉米秸和玉米根，水稻秸和水稻根)在潮棕壤地区温度、湿度适宜的前3个月(1999年7—月)迅速分解，之后进入缓慢分解阶段，其中根的分解残留率始终高于秸秆。经计算约有2／3的玉米根和稻根腐解产物残留在土壤里；分解至试验结束。所有物料的C/N比都趋于一致，约在10—13之间，与土壤腐殖质的洲比非常相近，说明这些物料已基本完成其腐殖化过程，而成为较稳定的有机组分、这对增加土壤有机质、培肥土壤非常重要。     

三江平原典型湿地的土壤植物总硫及水中硫酸盐的分布特征

以三江平原的3种主要沼泽类型——小叶樟沼泽、乌拉苔草沼泽、毛果苔草沼泽为研究对象,对其土壤和植物中的总硫质量分数及水中硫酸盐质量分数进行分析。3种沼泽土壤总硫质量分数的顺序为小叶樟沼泽(622.4 mg/kg)<乌拉苔草沼泽(820.5 mg/kg)<毛果苔草沼泽(1022.4 mg/kg);植物总硫质量分数的顺序为小叶樟(1638.5 mg/kg)<乌拉苔草(1796.9 mg/kg)<毛果苔草(1892.8 mg/kg);水中硫酸盐的质量分数为小叶樟沼泽(1.69 mg/kg)<乌拉苔草沼泽(1.81 mg/kg)<毛果苔草沼泽(2.00 mg/kg)。并探讨了典型湿地生态系统中硫质量分数的影响因素。     

Canopy structure versus physiology effects on net photosynthesis of mountain grasslands differing in land use

The present paper aims at investigating how changes in canopy structure and species physiology associated with the abandonment of mountain meadows and pastures affect their net photosynthesis. For this purpose, a multi-layer vegetation–atmosphere transfer (VAT) model is employed, which explicitly takes into account the structural and functional properties of the various canopy components and species. Three sites differing in land use are investigated, a meadow, a pasture and an abandoned area. Model simulations agree reasonably with measured canopy net photosynthetic rates, the meadow featuring the highest daily net photosynthesis, followed by the pasture and, finally, the abandoned area. A detailed process analysis suggests this ranking to be mainly due to bulk canopy physiology, which decreases from the meadow to the pasture and the abandoned area, reflecting species composition and species-specific photosynthetic capacities. Differences between the canopies with regard to canopy structure are found to be of minor importance. The amounts of green, photosynthetically active plant matter are too similar at the three sites to be a major source of variation in net photosynthesis. Large differences exist between the canopies with regard to the amount of photosynthetically inactive phytoelements. Even though a model analysis showed them to be potentially important, most of them are accumulated close to the ground surface, where they exert little influence on canopy net photosynthesis.     

Molecular receptive ranges of olfactory receptor neurones responding selectively to terpenoids, aliphatic green leaf volatiles and aromatic compounds, in the strawberry blossom weevil Anthonomus rubi

Summary. An important question in insect-plant interactions is which of the numerous plant compounds contribute to the perception of odour qualities in herbivorous insects and are likely to be used as cues in host-searching behaviour. In order to identify which plant-produced volatiles the strawberry blossom weevil Anthonomus rubi detects, we have used electrophysiological recordings from single olfactory neurones linked to gas chromatography and mass spectrometry. We here present 15 receptor neurone types specialised for naturally produced compounds present in the host and nonhost plants and two types for two aggregation pheromone components. The active compounds were terpenoids, aromatic and aliphatic esters, alcohols and aldehydes, some of which are induced by feeding activity of the weevils. The neurones were characterised by a strong response to one or two primary odorants and weaker responses to a few others having similar chemical structure. With one exception, the molecular receptive range of each neurone type was within one chemical group. Enantiomers of linalool separated on a chiral column activated two neurone types with different enantioselectivity. Inhibition by linalool of another neurone type, excited by α-pinene, indicated an additional mechanism for coding the information about this compound. Altogether, detection of 54 compounds by olfactory receptor neurones is shown, of which 40 have been chemically identified in this study. Thus A. rubi has the ability to detect a large number of odorants that may be used in host selection behaviour.