温州蜜柑宫川耐浮皮芽变系果实浮皮特性和耐贮性研究

【目的】探究宫川温州蜜柑（Citrus unshiu Marc.‘Miyagawa wase’）耐浮皮芽变系的果实品质、浮皮特性和耐贮性能,为耐浮皮柑橘新品种的选育和推广提供参考。【方法】连续多年测定比较耐浮皮芽变系及其对照母树宫川的果实主要品质性状包括单果质量、果形指数、色泽、硬度、可溶性固形物含量、可滴定酸含量、维生素C(Vc)含量和浮皮指数;观察测定宫川及其芽变系果皮特征和厚度,利用石蜡切片和透射电镜比较两者果皮细胞和亚细胞结构差异;通过常温贮藏试验,比较两者果实贮藏性能。【结果】芽变系成熟果实平均单果质量102.90 g,果形指数0.78,色调角h0值68.19,硬度0.96 kg·cm-2,可溶性固形物含量（w,后同）13.88%,可滴定酸含量0.62%,Vc含量29.87 mg·100 g-1,其中硬度、可溶性固形物和Vc含量均显著高于宫川,浮皮指数显著低于宫川;芽变系果实果皮厚度显著低于宫川,白皮层细胞排列相对整齐且细胞结构较为完整,宫川白皮层细胞表现质壁分离,细胞器降解,趋于衰老;常温贮藏过程中,芽变系果实硬度、可溶性固形物含量、可滴定酸含量等指标均高于同时期宫川,浮皮...     

常用农药对湛江红江橙和广州九里香柑桔木虱种群的室内药效

柑桔木虱(Diaphiorina citri Kuwayama)是柑桔黄龙病最重要的媒介昆虫,对其进行严格防控是阻延黄龙病传播的有效手段.采用室内药效测定方法,测定了 12种常用农药(采用生产上常用浓度)对广东重要柑桔品种红江橙(Citrus sinensis'Hongjiangcheng')和广州园林植物九里香(Mu...     

Role of endoplasmic reticulum stress in trimethylamine N-oxide-induced oxidative stress in human umbilical vein endothelial cells

AIM: To investigate whether endoplasmic reticulum stress is involved in trimethylamine N-oxide (TMAO)-mediated oxidative stress in human umbilical vein endothelial cells (HUVECs). METHODS: The cell viability was examined by CCK-8 assay. The cells were stained by DCFH-DA, and the intracellular level of reactive oxygen species (ROS) was observed by phase-contrast microscopy and detected by flow cytometric analysis. The protein levels of phospho-IRE-1α, IRE-1α and GRP78/BiP were detected by Western blot. RESULTS: TMAO exerted no significant effect on the viability of HUVECs. For a long period (>24 h), even a low concentration (10 μmol/L) of TMAO increased the oxidative stress level in the HUVECs (P<0.05). TMAO increased the phosphorylation level of IRE-1α and significantly up-regulated the protein level of GRP78/BiP in HUVECs (P<0.01). Pretreatment with STF-083010, an inhibitor of IRE1α, for 1 h reduced TMAO-induced oxidative stress in HUVECs (P<0.05). CONCLUSION: Endoplasmic reticulum stress is involved in TMAO-induced oxidative stress in HUVECs.     

High efficient expression of human endostatin in E.coli and its antiangiogensis activity

AIM: To examine the expression of human endostatin in E.coli, produce its fusion protein antibody and observe its biological activity. METHODS: Endostatin gene was amplified by polymerase chain reaction,recombined with plasmid vector pGEX-2T and induced expression with IPTG.The protein activity was tested by endothelial cell proliferation inhibitory assay.Inclusion body crudely purified was used to generate polyclonal antibody to detect its expression at mouse's liver and kidney etc. RESULTS: The protein expressed was 20kD after digestion by thrombin,it appeared the anti-angiogenesis activity and Western blotting indicated the expression of endostatin in liver and kidney of mouse. CONCLUSION: The successful expression of human endostatin and the preparation of polycolonal antibody indicated its potential application in anti-angiogenesis therapy and diagnosis tumors.     

网箱养鳝水体适宜水生植物的筛选

从经济价值、对水深的适应性及植株扩展度3个方面对长江流域适宜种植的23种水生植物进行了筛选．认为菜用睡莲（咖n加aeaspp．）、蕹菜（昂0埘0eaaquatiea）、菱角（Trapaspp．）及芡实（Euryaleferox）4种水生经济植物比较适合于网箱养蟮水体种植,并提出了相应的栽培技术要点。     

韭菜不同栽培方式综合效益比较试验

为推进韭菜周年均衡生产供应,进行了韭菜不同栽培方式综合效益比较试验。试验结果表明,常规露地栽培技术要求不高、投资低,但667 m2净收益仅4 257.1元;大棚栽培技术要求高、投资大,能增加元旦、春节期间的蔬菜种类,但净收益仅比露地栽培增加21.54%;韭菜软化栽培成本高,收益也高,667 m2净收益高达13 111.9元,能均衡周年供应,还能解决农村富余劳动力就业问题,但栽培上要注意选好苗、好地及管理好。     

What determines the spatial extent of landscape effects on species?

Context

Landscape ecologists are often interested in measuring the effects of an environmental variable on a biological response; however, the strength and direction of effect depend on the size of the area within which the environmental variable is measured. Thus a central objective is to identify the optimal spatial extent within which to measure the environmental variable, i.e. the “scale of effect”.

Objectives

Our objectives are (1) to provide a comprehensive summary of the hypotheses concerning what determines the scale of effect, (2) to provide predictions that can be tested in empirical studies, and (3) to show, with a review of the literature, that most of these predictions have so far been inadequately tested.

Methods

We propose 14 predictions derived from five hypotheses explaining what determines the scale of effect, and review the literature (if any) supporting each prediction. These predictions involve five types of factors: (A) species traits, (B) landscape variables, (C) biological responses (e.g. abundance vs. occurrence), (D) indirect influences, and (E) regional context of the study. We identify methodological issues that hinder estimation of the scale of effect.

Results

Of the 14 predictions, only nine have been tested empirically and only five have received some empirical support. Most support is from simulation studies. Empirical evidence usually does not support predictions.

Conclusions

The study of the spatial scale at which landscape variables influence biological outcomes is in its infancy. We provide directions for future research by clarifying predictions concerning the determinants of the scale of effect.

     

芋种子萌发特性的研究

以仰光×乐平及仰光×霞山2种杂交种子为试材,探究消毒方法、光照、温度、播种基质对芋种子萌发和生长的影响。结果表明:8%Na Cl O(无水酒精稀释)处理9min后用无水酒精清洗种子是最佳的芋种子消毒方法;种子或珍珠岩消毒对种子的萌发和子叶的生长无显著影响,但在有菌条件下,生长后期衍生出的细菌或真菌会影响子叶的后续生长;芋种子是喜光性种子,种子萌发的适宜温度为25~30℃;在培养土中,芋种子不萌发,湿润滤纸、无菌水、珍珠岩、沙子和MS培养基中芋种子的发芽率较高,但仅沙子和MS培养基中幼苗生长健壮;移栽于培养土后幼苗生长良好,成活率高达95%。     

Multi-scale study of bird species distribution and of their response to vegetation change: a Mediterranean example

Land use changes operate at different scales. They trigger a cascade of effects that simultaneously modify the composition or structure of the landscape and of the local vegetation. Mobil animals, and birds in particular, can respond quickly to such multi-scalar changes. We took advantage of a long term study on the response of songbirds to land-use changes on four Mediterranean islands in Corsica and Sardinia to explore the benefits of a multi-scale analysis of the relationships between songbird distribution, vegetation structure and landscape dynamics. Field data and aerial photographs were used to describe the vegetation at three different scales. Birds were censused by point counts. We used statistical variance decomposition to study how bird distribution and vegetation at various scales were linked. We analysed multi-scale vegetation changes (floristic composition, plot vegetation type, and landscape structure) and their consequences on bird distribution with multivariate and non-parametrical tests. The distribution of most species was linked to at least two spatial scales. The weight of a given scale was consistent with life-history traits for species whose biology was well-known. In the examples studied, vegetation composition, vegetation type and landscape changes that resulted from land abandonment negatively affected birds depending on open or heterogeneous areas. Our results emphasize that multi-scale analyses can greatly enhance our understanding of bird distribution and of their changes. Management of these populations should take into account measures at various spatial scales depending on the sensitivity of the species.     

Context matters: the landscape matrix determines the population genetic structure of temperate forest herbs across Europe

Landscape Ecology - Plant populations in agricultural landscapes are mostly fragmented and their functional connectivity often depends on seed and pollen dispersal by animals. However, little is...