芦荟植物SOD酶对甲醛气体胁迫的应答

首次实验研究了中华芦荟(Aloe rera var.chinensis (Haw)Berg.)植物对甲醛的吸收以及植物体内超氧化物歧化酶(SOD)活性的变化情况,旨在了解芦荟净化室内甲醛气体的生理机制.实验以玻璃箱模拟室内空间环境,用乙酰丙酮分光光度法测定模拟空间内甲醛的浓度,用邻苯三酚自氧化法测定SOD的活性.结果表明,有芦荟存在的条件下,模拟空间内甲醛气体浓度显著下降.随着通人甲醛量的增加,芦荟对甲醛的吸收有着较显著的增加,并且SOD酶活性的变化也越来越显著.芦荟体内SOD酶对甲醛气体的胁迫存在着一定程度的生理应激反应,芦荟对室内甲醛污染存在一定程度的净化作用.     

天水小陇山红豆杉(Taxus chinensis (Pilg.) Rehd)林土壤真菌多样性及其与生态因子的相关性

采用GPS系统采集了天水小陇山红豆杉林9块样地的土样,用稀释平板法对该区域真菌进行分离计数,进一步鉴定到属,并分析了真菌数量和类群与土壤养分、水分和pH等生态因子的相关性.结果表明,该区域土壤真菌数量和类群组成存在较大的空间变异,土壤真菌优势菌群的构成有相似性,青霉属、毛霉属为所有样地的优势菌群.真菌多样性分析表明,小陇山红豆杉物种多样性较丰富,不同样地多样性指数差异明显.土壤真菌总数、类群和多样性与土壤生态因子间的相关性分析表明,真菌总数与土壤pH呈显著负相关(R-0.796),与水分和有机质呈显著正相关;Shannon-Wiener指数与土壤有机质呈显著正相关;各属与土壤生态因子呈现不同的相关性.      

小白菜的干鲜状态对其铅的生物可给性的影响(Effects of Dry and Fresh States of Brassica chinensis on the Oral Bioaccessibility of Lead)

为了研究小白菜的干鲜状态对其铅的生物可给性的影响,设置了对照(不添加铅,本底值为32.37mg·kg-1)、300mg·kg-1和500mg·kg-13种土壤铅浓度处理的盆栽实验,并将收获的小白菜分别以干样和鲜样进行基于生理学的invitro人工胃肠模拟实验,测定其中铅的生物可给性.结果表明:栽种2个月后,小白菜铅含量分别达到0.38mg·kg-1、4.55mg·kg-1和12.50mg·kg-1(干重),对铅的富集系数分别为0.012、0.015和0.025,可能存在较高的健康风险.invitro实验表明:样品干鲜状态、铅浓度处理以及二者的交互效应是影响铅的生物可给性的重要因素.无论干样还是鲜样,铅在胃阶段和小肠阶段的溶解态量均随样品铅含量的增加而线性增加;对于同一铅浓度处理,鲜样中铅的生物可给性无论在胃阶段还是小肠阶段均显著高于干样(p<0.01).使用干样进行健康风险评价可能会低估小白菜中的铅对人体的健康风险.     

1H-NMR-based metabolomic study on toxicity of methomyl and methidathion in fish

A ¹H-nuclear magnetic resonance (NMR) spectroscopy with multivariate analysis was applied to detect the toxicity of antiacetylcholinesterase insecticides, methomyl (methyl (1E)-N-(methylcarbamoyloxy)ethanimidothioate) and methidathion (3-(dimethoxyphosphinothioyl sulfanylmethyl)-5-methoxy-1,3,4-thiadiazol-2-one), using zebrafish (Danio rerio) and Chinese bleak (Aphyocypris chinensis). Generally, methomyl and methidathion have been believed not to highly accumulate in fish tissues. However, these pesticides showed their toxicity by altering patterns of whole-body metabolites in neurotransmitter balance, energy metabolism, oxidative stress, and muscle maintenance in low concentrations. We used Pearson correlation analysis to contextualize the metabolic markers in pesticide treated groups. We observed that the positive correlations of choline with acetate and betaine in untreated control were shifted to null correlations showing acetylcholinesterase specific toxicity. This research demonstrated the applicability and potential of NMR metabolomics in detecting toxic effects of insecticide with a modicum of concentrations in aquatic environment.     

兰竹荔枝胚珠内源激素含量变化与胚胎发育的关系

以兰竹荔枝胚胎发育时期的正常胚珠与败育胚珠为试验材料,研究了胚胎发育与内源激素的关系,结果表明：正常胚珠中ＩＡＡ、ＧＡ１＋３和ＡＢＡ含量均在花后７ｄ达到峰值,随后呈下降趋势;但ＩＡＡ和ＧＡ１＋３含量在心形胚至鱼雷胚时期都有所回升,ＣＴＫ含量在球形胚之前一直很高,败育胚珠中ＡＢＡ含量在胚胎败育期保持较高水平,ＩＡＡ和ＧＡ１＋３则降到最低点,ＣＴＫ含量亦明显低于正常胚珠,ＺＲｓ、ＤＨＺＲｓ和ｉＰＡｓ含     

退化羊草草原在浅耕翻处理后植物群落生物量组成动态研究

利用统计方法研究了退化羊草草原浅耕翻后17年的群落生物量组成变化规律,结果表明:浅耕翻处理后地上生物量增长与恢复年限呈单峰型曲线,且在演替的前期和中期,群落生产力与降水并没有显著的相关关系,生物量的高低主要受群落组成结构的影响。群落地上生物量组成中禾本科占主导地位,藜科、菊科和蔷薇科在恢复前期和中后期比例增加,且与禾本科有一定的负相关关系。从生活型组成来看,根茎禾草生物量占总生物量的90%以上,群落初级生产力及其年度动态与多年生根茎禾草和多年生杂类草2个功能群的地上生物量均有极显著的相关关系。就群落生物量植物水分生态类型组成来看,中旱生、旱生植物占有绝对的优势,群落地上生物量与中旱生植物、旱生植物功能群地上生物量也具有较显著的正相关关系。多样性指数在处理后的总变化趋势为开口向上的抛物线状。植物群落多样性变化主要归功于其物种的均匀性变化。同时禾本科、菊科、蔷薇科植物生物量,根茎禾草、丛生禾草、直根型杂类草的生物量与多样性指数呈显著或极显著的线性相关关系。浅耕翻对更新退化羊草草原、提高产草量、改善草质均有明显效果,从利用的角度看,浅耕翻处理后第四年即根茎禾草占优势以后可有计划地利用。     

Role of nitrification inhibitor DMPP( 3,4-dimethylpyrazole phosphate) in NO3--N accumulation in greengrocery(Brassica campestris L. Ssp. Chinensis )and vegetable soil

The influence of nitrification inhibitor(NI) 3,4-dimethylpyrazole phosphate (DMPP) on nitrate accumulation in greengrocery ( Brassica campestris L. ssp. chinensis) and vegetable soil at surface layer were investigated in field experiments in 2002 and 2003.Results showed that NI DMPP took no significant effect on yields of edible parts of greengrocery, but it could significantly decrease NO3^--N concentration in greengrocery and in vegetable soil at surface layer. In addition, NI DMPP could reduce the NO3^--N concentration during the prophase stage of storage.     

中国对虾血细胞包掩作用的超微结构和组织化学观察

用鳗弧菌注射中国对虾,对其体内血细胞的包掩作用进行了超微结构和组织化学观察．结果表明：在注菌的对虾体内,包囊产生于多种器官和组织,在释放颗粒的过程中,半颗粒细胞和颗粒细胞的表面即发生变化,开始与周围细胞相粘接;在包囊中心是电子不透明的非结构团块;含吞噬泡的透明细胞也常被包围在包囊内,构成包囊的血细胞中细胞器趋于退化,在组织化学上表现为细胞中的ＲＮＡ大为减少,色氨酸几乎消失;然而,包囊从开始形成起,就呈Ｃｈｅｖｒｅｍｅｎｔ铁氰化钾法强阳性反应,此反应可被Ｂａｒｎｅｔ碘液法封闭．推测这一现象与黑色素生成有关．     

昆嵛山盐肤木RhuschinensisMill．群落特征及其物种多样性

根据野外典型样方调查结果,以群落植物种类组成、群落外貌特征、群落垂直结构特征、群落多样性几项指标,分析山东半岛昆嵛山国家级自然保护区盐肤木Rhuschinensis群落特征。结果表明：盐肤木群落共出现种子植物66种,隶属于32科57属。在盐肤木群落属的区系组成中,群落植物主要由温带区系和热带区系成分组成,其中温带植物属占显著优势,其次为热带分布属,说明该群落具有明显的温带性质,并具有过渡特征。群落层次分明,有乔木层、灌木层、草本层3个层次,各层次的优势种依次为盐肤木和赤松Pinusdensiflora、麻栎Quercusacutissima、披针叶苔草Carexlanceolata。盐肤木群落的物种多样性由高到低依次为灌木层、乔木层、草本层,低均匀度导致物种丰富度最高的草本层具有最低的物种多样性。调查显示盐肤木幼苗幼树多,自我更新良好,群落处于稳定增长状态。通过对群落特征和物种多样性的研究,揭示了昆嵛山盐肤木群落的自然生态规律,为保护和开发利用盐肤木提供了科学依据。     

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.