浙西南食用菌的可持续利用与生态环境研究

近十年来,食用菌在浙西南山区发展迅猛,大大促进了当地农村经济的发展,为农民脱贫致富发挥了重要作用,但也存在着一些问题。针对食用菌生产对生态环境的影响,作者提出了浙西南山区持续发展食用菌的若干建设和对策。     

Genetic influence on caste in the ant Camponotus consobrinus

Genetic influences on polyethism within social insect colonies are well known, suggesting that the determination of caste (soldiers and minor workers) may also be genetically mediated. The Australian sugar ant Camponotus consobrinus is suitable for such a study, having soldiers and minor workers that follow a complex allometry. Further, although most C. consobrinus colonies are monogynous, 13 of 42 surveyed using microsatellites were found to be polygynous. Thus, although a minority of colonies were polygynous, the great majority of queens live in polygynous colonies. From the 29 monogynous colonies studied, we inferred that the queens are monandrous. Ants from four polygynous colonies were assigned to families on the basis of microsatellite genotypes, after measurements had been taken of head width and scape length. These measurements reflect a complex allometry interpretable as soldier and minor worker growth curves with a large changeover zone. Genetic influence on caste determination was examined by testing for differences between families within colonies in the distribution of scape lengths, residuals from the overall colony allometric curve, and proportions of soldiers and minor workers (as determined by head width falling above or below the inflection point of the overall colony allometric curve). Families in all four colonies differed significantly in caste proportions and in head-width distributions, and three of the four colonies showed significant differences between families in residuals from the overall colony growth curve. Nested ANOVAs using head widths and scape-length residuals showed that when the effect of family is removed, intercolony differences in allometry are negligible. This evidence indicates genetic rather than environmental causes for the observed differences between families. We speculate that this variation may reflect some selective advantage to within-colony heterogeneity between families or that selective differences are few between a wide array of family growth patterns. Received: 16 June 1999 / Received after revision: 13 September 1999 / Accepted: 25 September 1999     

典型野生食用菌重金属含量及其人体健康风险评价

土壤重金属污染是影响生态环境、食品安全和人体健康的重要因素.云南省土壤重金属背景值较高,且矿产资源丰富、采矿活动频繁,导致土壤重金属含量较高.野生食用菌是高效重金属储积器,云南是中国野生食用菌最大产区.因此,本文以云南省8种典型野生食用菌为研究对象,探究其重金属含量(汞、镉、铅、锌、铜、砷)与分配特征,采用单因子污染指...     

电导率法快速鉴别潲水油

许多地方出现了潲水油(或地沟油)回流到食用油市场的现象,为寻找鉴别潲水油的方法,研究了用电导率法鉴别潲水油。将油样和水混合,经过超声波振荡,用电导率仪对其水相进行测定。实验结果表明经过处理的潲水油和合格食用植物油,其水相的电导率值有明显差别,处理后的合格食用植物油水相电导率都在10μs/cm以下,最小的只有3.75μs/cm,而潲水油和水的混合物经过超声振荡后,其水相电导率几乎在100μs/cm以上,最高可达173.4μs/cm。初步认为可将电导率测定作为鉴别潲水油和合格食用植物油的一种方法。     

Reduced Diversity and Complexity in the Leaf-Litter Ant Assemblage of Colombian Coffee Plantations

Abstract:  Coffee agroecosystems have recently undergone a dramatic intensification in Colombia, a megadiverse country, especially in terms of the nature of shade cover. We tested for changes in the composition, ecological associations, and diversity of ants (Hymenoptera: Formicidae) along a gradient of intensification of coffee production in the Colombian Andes. We surveyed 16 farms in two regions, classified into four management types: (1) forest (no agriculture), (2) organic polygeneric shaded coffee, (3) monogeneric shaded coffee, and (4) sun coffee (unshaded). Forty sampling units (20 1-m² plots on the ground and 20 coffee bushes) were established at each farm between 2001 and 2002. We sampled with a mini-winkler litter extraction technique and through visual searching. Organic polygeneric shaded-coffee plantations contained significantly higher ant species richness, and their ant assemblages resembled the forest patches more than any other management type. The number of statistically significant associations among ant species dropped with production intensification, as did the number of ant species involved in such associations. The network of ant associations in shaded systems transformed into an extremely simplified network in sun coffee, with a few dominant ants extending almost entirely throughout the crop. Intensification of coffee agriculture not only caused loss of litter ant species (especially forest species) but also a reduction in the complexity of the ant assemblage in the leaf litter of this agroecosystem.     

Interspecific aggression in colonies of the slave-making ant Harpagoxenus sublaevis

Colonies of the slave-making ant, Harpagoxenus sublaevis, may simultaneously contain workers of several Leptothorax slave species. We observed aggressive interactions among slave-makers, between slavemakers and slaves, and among slaves in 11 mixed colonies. The first two types of aggression appear to be correlated with reproductive competition for the production of males. Aggressive interactions among slaves, however, occurred mainly between slaves belonging to different species. In two colonies, in which one slave species clearly outnumbered the other, the majority attacked and finally expelled all nestmates belonging to the minority species. Our observations thus suggest that in Harpagoxenus colonies a homogeneous colony odor is not always achieved and that heterospecific slaves may occasionally be mistaken for alien ants. Gas chromatographic analyses of ants from mixed colonies similarly show that cuticular hydrocarbon profiles may differ strongly between heterospecific nestmate slaves.     

Vibrational communication between hitchhikers and foragers in leaf-cutting ants (Atta cephalotes)

Abstract In a foraging column of the leaf-cutting ant Atta cephalotes, minim workers (the smallest worker subcaste) hitchhike on leaf fragments carried by larger workers. It has been demonstrated that they defend leaf carriers against parasitic phorid flies. The present study examines the cues used by the potential hitchhikers to locate leaf carriers. As recently reported, foraging workers stridulate while cutting a leaf fragment, and the stridulatory vibrations serve as closerange recruitment signals. We tested the hypothesis that these plant-borne stridulatory vibrations are used by the potential hitchhikers to locate workers engaged in cutting. Three different lines of evidence support this view. Firstly, the repetition rate of the stridulations produced by foraging workers increases significantly as foragers maneuver the leaf fragment into the carrying position and walk loaded to the nest. This is the moment when hitchhikers usually climb on the leaf. Although the leaf-borne stridulatory vibrations are considerably attenuated when transmitted through the workers' legs, they can nevertheless be detected at short distances by minims. This subcaste is several times more sensitive to substrate-borne vibrations than larger workers. Secondly, when a stridulating and a silent leaf were simultaneously presented at the foraging site, minim workers spent significantly more time on the stridulating than on the silent leaf. Thirdly, hitchhiking was more frequent in leaf carriers which cut fragments out of the stridulating leaf than in those cutting the silent leaf.Abstract In a foraging column of the leaf-cutting ant Atta cephalotes, minim workers (the smallest worker subcaste) hitchhike on leaf fragments carried by larger workers. It has been demonstrated that they defend leaf carriers against parasitic phorid flies. The present study examines the cues used by the potential hitchhikers to locate leaf carriers. As recently reported, foraging workers stridulate while cutting a leaf fragment, and the stridulatory vibrations serve as closerange recruitment signals. We tested the hypothesis that these plant-borne stridulatory vibrations are used by the potential hitchhikers to locate workers engaged in cutting. Three different lines of evidence support this view. Firstly, the repetition rate of the stridulations produced by foraging workers increases significantly as foragers maneuver the leaf fragment into the carrying position and walk loaded to the nest. This is the moment when hitchhikers usually climb on the leaf. Although the leaf-borne stridulatory vibrations are considerably attenuated when transmitted through the workers' legs, they can nevertheless be detected at short distances by minims. This subcaste is several times more sensitive to substrate-borne vibrations than larger workers. Secondly, when a stridulating and a silent leaf were simultaneously presented at the foraging site, minim workers spent significantly more time on the stridulating than on the silent leaf. Thirdly, hitchhiking was more frequent in leaf carriers which cut fragments out of the stridulating leaf than in those cutting the silent leaf.Communicated by P. Pamilo     

Trail pheromones and Dufour gland contents in three <Emphasis Type="Italic">Camponotus</Emphasis> species (<Emphasis Type="Italic">C. castaneus,C. balzani,C. sericeiventris</Emphasis>: Formicidae,Hymenoptera)

Summary. By means of gas chromatography, gas chromatographic coupled mass spectrometry and behavioral analysis the major trail pheromone components from the hindgut of the formicine species Camponotus castaneus, C. balzani and C. sericeiventris were identified. The trail pheromone of C. castaneus is 3,5-dimethyl-6-(1-methylpropyl)- tetrahydro-2H-pyran- 2-one, and that of the other two species is 3,4-dihydro-8-hydroxy-3,5,7-trimethylisocoumarin. Although both compounds release precise trail following behavior in the respective species, the major recruitment signal in the three Camponotus species appears to be formic acid discharged from the poison gland. The composition of the Dufour gland secretions of C. castaneus and C. sericeiventris is similar, but that of the hypertrophied Dufour gland of C. balzani is very different from any other Camponotus Dufour gland content described up to date: it contains large amounts of esters, the major compound of which is octyl hexanoate, which makes up 97% a/a of the total volatiles.     

无公害食用菌生产技术规程的制定研究

通过分析近年来我国食用菌生产管理和产品质量安全存在的问题,论述了开展无公害食用菌生产的重要性.同时吸收各地的生产经验.根据国家有关标准,从食用菌生产场所的选择、培养基材料和水的要求、栽培管理、病虫害防治、采后处理、加工贮藏和产品质量安全检测等几个方面,提出了一整套较系统的无公害食用菌生产技术操作规程.该项技术规程在生产上的推广应用,对提高食用菌生产技术水平、改善和保障食用菌产品质量、增强产品在国际市场的竞争力将产生积极的推动作用.     

Chemical composition of selected seaweeds from the Indian Ocean,KwaZulu-Natal coast,South Africa

The chemical composition of three edible seaweeds (Codium capitatum, Hypnea spicifera and Sargassum elegans) and two inedible seaweeds (Halimeda cuneata and Spyridia hypnoides) from the Indian Ocean along the KwaZulu-Natal East Coast, South Africa were investigated as a function of seasonal variation. The proximate compositions of the edible seaweeds were determined. In edible seaweeds, the moisture level ranged from 85.4 to 89.5%, protein from 6.1 to 11.8%, lipids from 7.5 to 13.1% and carbohydrates from 37.8 to 71.9%. Elemental concentrations in the five studied seaweeds varied significantly with season (P < 0.05) with mean elemental concentrations (in µg g^?1, dry weight) being: Ca (29 260), Mg (6 279), Fe (1 086), Cu (145.9), Mn (48.32), As (24.29), Zn (15.65), Ni (9.83), Cr (5.78), Pb (4.84), Co (0.87) and Se (0.86). The concentrations of As were particularly high in S. elegans, ranging from 94.70 ± 6.6 µg g^?1 in winter to 65.10 ± 2.3 µg g^?1 in summer. Hierarchical cluster analysis showed similar distribution of elements in edible seaweeds which was dissimilar to that in inedible seaweeds. This study suggests that edible macro alga, C. capitatum and H. spicifera, could be potential sources of most essential nutrients and may contribute positively to the diet without posing the risk of adverse health effects due to low concentrations of toxic elements. However, due to high levels of As in S. elegans, its consumption should be moderated to reduce dietary exposure to this toxic element.