重金属对平菇菌丝生长、产量和质量的影响

通过在培养料中添加不同浓度的4种重金属(Pb、Cd、Hg、As),研究这些元素对平菇菌丝生长和子实体产量的影响,以及这些元素在子实体中的累积规律及其对平菇安全质量的影响。结果表明,4种重金属在较高浓度条件下,可明显抑制菌丝的生长,显著降低子实体的产量和生物学效率,同时严重影响平菇的安全质量。子实体中4种重金属的含量随其在培养料中浓度的增加而增加,根据NY/T 5095-2006中重金属限量要求,建议平菇培养料中Cd、Hg和As的浓度应分别低于0.35 mg.kg-1、1.88 mg.kg-1、4.03 mg.kg-1(湿重);根据NY/T 749-2003中重金属限量要求,建议平菇培养料中Cd、Hg和As的浓度应分别低于0.35 mg.kg-1、0.88 mg.kg-1、1.96 mg.kg-1(湿重)。     

培养料中重金属对真姬菇产品质量安全的影响

研究表明，子实体中As、Hg、Pb、Cd4种重金属的浓度随着添加水平升高而增大．但是富集系数逐渐降低。通过对培养料中重金属添加浓度与子实体含量的回归分析发现二者的线性相关关系显著。按照国家标准中As、Hg、Pb、Cd的最高允许含量确定真姬菇的培养料中As、Hg、Pb、Cd的安全限量值应不高于5．0、1．0、3．5、1．0mg／kg。     

Agaricus bisporus野生驯化新品种“沐野1号”的分子遗传鉴定与重金属富集规律研究

为探明双孢蘑菇"沐野1号"的分子生物学分类地位以及子实体重金属富集情况,在培养料中分别添加不同质量浓度铅(Pb)、砷(As)、镉(Cd)、汞(Hg)和铬(Cr),测定子实体中重金属含量。结果表明:"沐野1号"菌丝体的rDNA ITS与双孢蘑菇(Agaricus bisporus)同源性比例高达99%。在重金属检测试验条件下,子实体中Pb、As的富集量未超过绿色食品的标准,而当Hg添加质量浓度大于0.2mg·mg-1、Cd添加质量浓度大于0.5mg·mg-1时,子实体中的Hg和Cd含量超过了绿色食品的限量标准。     

金针菇、杏鲍菇菌丝对四种重金属耐受和富集特性的研究

以金针菇和杏鲍菇菌为试材,在平板培养基和液体发酵培养基中添加不同浓度梯度Pb、Cd、As、Hg重金属,通过测量菌丝日均生长速度、菌丝体干质量、菌丝体及发酵液中重金属含量等指标,进行重金属富集模型建模,研究不同菌类对不同种类重金属耐受及富集特征,以期为菌类富集重金属机理提供参考依据。结果表明:重金属Pb、Cd、As、Hg对菌丝生长及菌丝球量表现为低浓度(低于1mg·L~(-1))促进、高浓度(高于5mg·L~(-1))抑制,适宜浓度(1～5mg·L~(-1)浓度)的重金属Pb、Cd、As对菌丝的生长有一个明显前期抑制后期菌丝恢复正常生长的现象。金针菇和杏鲍菇菌丝体均表现为对重金属Cd和Pb高度富集,最大富集量分别达到Cd 619、424mg·kg~(-1) DW以及Pb 449、844mg·kg~(-1) DW,对重金属As和Hg富集量较小,最大富集量分别为As 49、21 mg·kg~(-1) DW以及Hg 44、40mg·kg~(-1) DW。不同菌类菌丝体对同一种重金属的富集饱和点不同,如金针菇菌丝体对Pb的富集饱和点是452 mg·kg~(-1) DW,杏鲍菇菌丝体对Pb的富集饱和点是902mg·kg~(-1) DW。同一菌类对不同重金属的富集饱和点差异较大,如杏鲍菇对Cd的富集饱和点为429mg·kg~(-1) DW,对As的富集饱和点为22.4mg·kg~(-1) DW。     

培养料中重金属元素对杏鲍菇子实体产量和质量的影响

工厂化栽培过程中,培养料中添加不同浓度的As、Hg、Pb和Cd,研究这些元素对杏鲍菇子实体产量的影响和在子实体中的累积规律.结果表明,子实体中As、Hg、Pb和Cd的含量随其在培养料中浓度的增加而增加,而且As、Hg和Cd会显著降低生物学效率.根据GB 7096-2003和NY/T 749-2003中食用菌干品的重金属限量要求,建议杏鲍菇培养料中As、Hg、Pb和Cd的浓度应分别低于0.5、1.0、3.5和1.0 mg/kg.     

四川部分地区3种食用菌中7种重金属含量测定

采用原子吸收法和原子荧光法对四川部分地区木耳、香菇、平菇3种常见食用菌中Cu、Mn、Cr、Hg、As、Pb和Cd等7种重金属元素进行测定。结果发现,在被检测的食用菌中Cr的平均含量最高,As的平均含量最低,所有样品中Cr含量均超标,33%样品中Hg含量超标,11%样品中Cd含量超标;同时还发现,不同菌种对这7重金属的富集能力差异显著,不同来源地的同种食用菌中重金属含量水平也有较明显的差异。     

四种重金属对食用菌菌丝生长及子实体富集量影响

为探明重金属元素对杏鲍菇和金针菇生长的影响及子实体重金属富集情况,试验在培养料中分别添加不同质量浓度铅(Pb)、砷(As)、镉(Cd)、汞(Hg),观察供试食用菌菌丝生长形态、生长速度,统计计算第一潮菇的生物转化率,测定子实体中重金属含量。结果表明:培养料添加重金属质量浓度小于1 mg/kg时,菌丝生长速度变慢,但菌丝更洁白浓密,第一潮菇生物转化率更高;重金属质量浓度大于1 mg/kg时,会明显抑制菌丝的生长,且菌丝稀疏、长势差,第一潮菇生物转化率下降;试验条件下,子实体中Pb、As的富集量未超过绿色食品的标准,Hg添加质量浓度大于0.2 mg/kg、Cd添加质量浓度大于0.5 mg/kg时,金针菇和杏鲍菇子实体中的Hg和Cd的含量开始超过绿色食品的限量标准。     

菜薹（菜心）对土壤中重金属的富集特征及产地土壤安全临界值

通过采集珠三角地区蔬菜产地原位土壤（非人工添加重金属）进行盆栽试验，研究了Cd、Pb、As、Hg、Cr 5种重金属在种植菜薹土壤中的活性，菜薹可食部分对土壤中全量和有效态重金属的富集特征，并探讨了5种重金属在土壤产地环境中的安全临界值以及土壤理化性质对菜薹吸收重金属的影响。结果表明：种植菜薹的土壤中重金属的活性顺序为Cd＞Pb＞As＞（Cr、Hg），菜薹对重金属的富集能力顺序为Cd＞Cr＞As＞Pb。依据《食品中污染物限量》（GB2762-2005）进行方程拟合，得出适合菜薹种植土壤的重金属全量限量值分别是：Cd，1.18 mg?kg-1|Pb，401.93 mg?kg-1|As，25.67 mg?kg-1|Cr，150.71 mg?kg-1，有效态重金属限量值分别是：Cd，0.64 mg?kg-1|As，3.05 mg?kg-1|Cr，4.93 mg?kg-1。菜薹对Hg富集能力弱，在供试土壤Hg浓度范围内菜薹中Hg含量均未超过限量值。     

毛头鬼伞子实体对重金属元素的富集特性

通过对毛头鬼伞(Coprinus comatus)产区中原辅材料中铅(Hg)、镉(Cd)、砷(As)、汞(Pb)4种重金属含量的检测和使用添加不同浓度重金属栽培材料的栽培试验,分析栽培原辅料中重金属含量对子实体中重金属含量的影响,为毛头鬼伞的安全生产提供参考。试验结果表明,除水之外的13个测试原辅材料样品中均含一定量的重金属元素;子实体中的重金属含量随着栽培材料中重金属元素含量的增加而呈上升趋势,子实体对覆土和对栽培基质中4种重金属元素的富集强弱分别为Hg>Cd>As>Pb和Hg>Cd>Pb>As,其中对覆土和栽培基质中重金属汞分别表现较弱和一定的富集作用。     

4种重金属元素在平菇栽培过程中的迁移特性初探

试验以河南省栽培规模较大的平菇作为研究对象,在培养料中人为添加一定量的铅、镉、汞、砷四种有害重金属,研究这4种重金属在平菇栽培过程中的富集和迁移规律。结果表明,培养料中重金属含量直接影响平菇子实体中重金属含量,并随着培养料中添加量的增加而增加;在未人为添加重金属的情况下生产的平菇子实体符合绿色食品标准。平菇对铅、镉、汞、砷4种有害重金属元素的富集能力各有差异,其中砷在平菇栽培过程中的富集和迁移能力最强,当栽培料中砷添加量为0.10 mg/kg时,平菇对砷的富集系数最高,达到630%。     

Fruit growth,cuticle deposition,water uptake,and fruit cracking in jostaberry,gooseberry, and black currant

Fruit cracking after rain limits the production of a number of crops, including some Ribes species. To gain a better understanding of the factors involved in cracking, fruit growth, deposition of the cuticular membrane (CM), water uptake and fruit cracking were studied in black currant (Ribes nigrum L. cv. Zema), gooseberry (Ribes uva-crispa L. cv. Rote Triumph), and jostaberry (Ribes nidigrolaria B. cv. Jostine). Fruit surface area and fresh mass increased continuously throughout development, whereas deposition of the CM was biphasic. CM mass per fruit increased rapidly up to 42, 41, and 49 days after full bloom (DAFB) in black currant, gooseberry, and jostaberry, respectively. Thereafter, CM mass per fruit remained constant in gooseberry and jostaberry or increased at a lower rate in black currant. The cessation of or reduced rate of CM deposition resulted in a decrease in CM mass per unit area in all berries. Elastic strain of the CM at maturity averaged 23.8% and 19.5% in gooseberry and jostaberry, respectively, and only 8.2% in black currant. Microcracks in the CM were observed first in gooseberry and jostaberry 64 DAFB, whereas there were no microcracks in black currant. Water uptake into mature detached berries was linear over 2 h of incubation. Rates of uptake were highest in gooseberry followed by black currant and jostaberry. Relative uptake was similar via the cut end of the pedicel (32.1%), the apex of the fruit (34.7%) and the fruit surface (33.2%). Rates of water uptake through the fruit surface were positively related to surface area. Average fruit water potential for black currant, gooseberry, and jostaberry was −2.14 ± 0.17, −1.24 ± 0.03, and −1.89 ± 0.20 MPa, while the permeability for osmotic water uptake was 7.7 ± 0.4 × 10⁻⁸, 5.2 ± 0.1 × 10⁻⁸, and 3.3 ± 0.3 × 10⁻⁸ m s⁻¹. Incubating whole fruit in deionized water for 72 h resulted in more cracked jostaberries (94%) than black currants (74%) or gooseberries (50%). A comparison of our findings in Ribes berries with published data for the sweet cherry drupe revealed that the berries fitted the relationships established in sweet cherry among fruit growth, cuticle deposition, strain of the cuticle, microcracking, permeability for osmotic water uptake, frequency of stomata and cracking. The Ribes berries were less susceptible to cracking than sweet cherry.     

Theory and language in landscape analysis,planning, and evaluation

A soft paradigm for landscape analysis is presented. This paradigm focuses on the analysis of function first, and then on structure. The objective is to determine which factors are operationally significant, how these factors bring about change, and how they define the spatial characteristics of landscapes.     

Resilience, experimentation, and scale mismatches in social-ecological landscapes

Growing a resilient landscape depends heavily on finding an appropriate match between the scales of demands on ecosystems by human societies and the scales at which ecosystems are capable of meeting these demands. While the dynamics of environmental change and ecosystem service provision form the basis of many landscape ecology studies, enhancing landscape resilience is, in many ways, a problem of establishing relevant institutions that act at appropriate scales to modify and moderate demand for ecosystem services and the resulting exploitation of ecosystems. It is also of central importance for landscape sustainability that institutions are flexible enough to adapt to changes in the external environment. The model provided by natural ecosystems suggests that it is only by encouraging and testing a diversity of approaches that we will be able to build landscapes that are resilient to future change. We advocate an approach to landscape planning that involves growing learning institutions on the one hand, and on the other, developing solutions to current problems through deliberate experimentation coupled with social learning processes.     

Road Density and Landscape Pattern in Relation to Housing Density,and Ownership,Land Cover,and Soils

Roads are conspicuous components of landscapes and play a substantial role in defining landscape pattern. Previous studies have demonstrated the link between roads and their effects on ecological processes and landscape patterns. Less understood is the placement of roads, and hence the patterns imposed by roads on the landscape in relation to factors describing land use, land cover, and environmental heterogeneity. Our hypothesis was that variation in road density and landscape patterns created by roads can be explained in relation to variables describing land use, land cover, and environmental factors. We examined both road density and landscape patterns created by roads in relation to suitability of soil substrate as road subgrade, land cover, lake area and perimeter, land ownership, and housing density across 19 predominantly forested counties in northern Wisconsin, USA. Generalized least squares regression models showed that housing density and soils with excellent suitability for road subgrade were positively related to road density while wetland area was negatively related. These relationships were consistent across models for different road types. Landscape indices showed greater fragmentation by roads in areas with higher housing density, and agriculture, grassland, and coniferous forest area, but less fragmentation with higher deciduous forest, mixed forest, wetland, and lake area. These relationships provide insight into the complex relationships among social, institutional, and environmental factors that influence where roads occur on the landscape. Our results are important for understanding the impacts of roads on ecosystems and planning for their protection in the face of continued development.     

Comparisons of qualitative and quantitative issues in the fruit supply industries in The Netherlands,Poland, Greece,and Spain

Summary

This paper presents an overview of the fruit supply chains in Poland, Spain, Greece, and the Netherlands. The roles of the different participants in the functioning of the fruit supply chains are presented, along with their quantitative characteristics. Although apple production was most popular in northern countries (i.e., Poland and The Netherlands), while in southern countries (i.e., Spain and Greece) citrus fruit (especially orange), grape, and peach production were most important, the participants along the fruit supply chains were the same in all cases: namely, research centres and seed companies, nurseries, fruit producers, co-operatives, fruit processors, wholesalers, retailers, and the food service sector. Any differences lay mainly in the level of concentration among participants at each stage of the fruit supply chains. Despite an ongoing process of consolidation, the fruit processing sector remains fragmented. There were only a small number of large enterprises that had a considerable position in multi-national markets, alongside a large number of much smaller entities that served local, regional, and national markets. With respect to product distribution in the fruit supply chains, the most characteristic feature was the increasing concentration of the retail trade.     

中国''''99昆明世界园艺博览会蔬菜瓜果园

蔬菜瓜果园作为中国’99昆明世界园艺博览会六大专题展园之一 ,占地 4 90 0ｍ2 。园内以农舍草屋为中心 ,通过瓜架、篱笆、草亭及蔬菜瓜果栽培 ,构出一幅农家乐园式的田园风光。另外 ,通过集中展示中国蔬菜瓜果的科技生产水平 ,丰富的资源优势 ,色彩缤纷、新奇别致的蔬菜瓜果品种 ,来突出本次世博会的主题“人与自然 ,和谐发展———迈向 2 1世纪” ,从而展现“蔬菜瓜果园艺是人类赖以生存的重要食源和艺术”为主题思想的蔬菜瓜果园内涵。　　蔬菜瓜果园位于世博园主入口世博大道南侧 ,与盆景园、药草园相邻。在总体布局、栽培上充分运用园…     

Vegetation-mediated feedback in water, carbon, nitrogen and phosphorus cycles

Since the industrial revolution, industry, traffic and the manufacture and application of nitrogenous fertilizers have increased carbon dioxide emissions and accelerated the nitrogen (N) cycle. The combined effects of a warming climate, CO₂ fertilization, land-use change and increased N availability may be responsible for primary productivity increases in many parts of the world. Enhanced productivity may lead to shifts in albedo and transpiration, which feed back to the water cycle through heat fluxes and precipitation. Plants may also respond to elevated CO₂ by closing their stomata or by structurally adapting their stomatal density and size, which potentially diminishes transpiration. Intensification of agriculture has also led to an increase in both nitrogenous (N) and phosphorus (P) fertilization. The combined effect of atmospheric N deposition and P fertilization has distorted the balance between N and P availability in many ecosystems. The active role of plants in accessing nutrients from the soil may trigger switches in nutrient availability, triggering shifts in plant productivity and species composition in these ecosystems and therefore also in the carbon (C) cycle. In response to global change, the above plant responses may influence each other positively or negatively and may impact on the elemental cycles of C, N and P and the water cycle. We are only beginning to understand how these four cycles interact, the role of plant processes and vegetation in these interactions, and the net outcome for plant competition, vegetation distribution, landscape development and directions of global change. In this paper we have integrated a number of recent research findings into known relationships that together elucidate interactions between these cycles through vegetation, and could potentially have unexpected effects on landscapes and larger-scale systems (continental, global). These interactions include processes operating at very distinct temporal and spatial scales, in which terrestrial ecosystems and their spatial organization in the landscape are key. We argue that to better understand the effects of changes in land cover and land use on biogeochemical and biogeophysical fluxes, it is necessary to account for feedbacks via vegetation and how these interfere with elemental cycles. Finally, we suggest directions for further research to fill the current knowledge gaps.     

榛仁中氮、磷、钾、钙与贮藏物质的相关性分析

以杂种榛优良品系为试材,分析氮、磷、钾、钙与贮藏物质的相关性。结果表明:氮、磷、钾和钙与脂肪显著或极显著正相关。氮、磷和钙与蔗糖显著或极显著正相关,‘82-11’品系中的磷和钾与可溶性总糖显著或极显著正相关,‘84-237’品系中的钙与可溶性总糖显著正相关,‘84-402’品系中的磷素与可溶性总糖显著正相关。     

江汉平原麦瓜棉菜一年四熟栽培技术

江汉平原是国家优质粮食、优质棉花和双低油菜重要生产基地,也是湖北省西瓜主产区。种植西瓜对增加农民收入、丰富市场、发展农村经济、提高土地利用率具有重要作用。江汉平原西瓜生产的突出特点是间作套种,早在20世纪70年代就推广了“麦／／瓜-稻”这种水旱、粮经作物配套种植的优化模式．并获得原荆州地区科技进步二等奖。由于西瓜间作套种提高了单位面积的经济效益、