Biochemical studies on blossom end rot of tomatoes

The causes of cell wall necrosis in Blossom End Rot (BER) of tomatoes have been investigated by comparing enzyme activities in healthy and affected tissues in the cultivars Grenadier and Moneymaker. Changes in the mineral contents of the tomatoes were in accordance with those of calcium deficient tissues. The phenolic contents of the affected tissues were increased as also were caffeic and chlorogenic acids. Phenolase and peroxidase activities were higher in affected fruits white catalase activities were higher in healthy fruits. ¹⁴C-labelled leucine was incorporated into the proteins of the healthy fruits to the greatest extent but cell wall proteinbound hydroxyproline was greatest in affected fruits.     

Biocontrol of Pests of Apples and Pears in Northern and Central Europe: 2. Parasitoids

The parasitoids of arthropod pests of apple and pear in northern and central Europe and their use as biological control agents are reviewed. The review demonstrates that apple and pear pests are host to a large and varied parasitoid fauna. All important pests are known to be host of parasitoids, but many parasitoids play only a minor part in regulating populations of their host. However, many parasitoid species are important natural enemies and some effectively regulate pest populations in unsprayed and/or commercial (insecticide sprayed) apple or pear orchards either individually or as part of parasitoid guilds. Exploitation/fostering of existing populations of parasitoids has been demonstrated to be an effective or partially effective approach for natural control of several important pest species. Important examples include natural regulation of the apple sawfly by Lathrolestes ensator and Aptesis nigrocincta, of the summer fruit tortrix moth by Colpoclypeus florus and Teleutaea striata, of leaf midges by Platygaster demades, of woolly aphid by Aphelinus mali and of leaf mining moths by guilds of parasitoid species. Introduction of parasitoids is an alternative approach to the exploitation of parasitoids already present in the orchard. This approach has been little explored and its success rate has been low, mainly confined to the control of non-indigenous pests by introducing parasitoids from their native region. Mass production methods for parasitoids are difficult and costly and are likely to be economic only where long-term populations can be established. Even where low cost mass culture techniques are developed, the degree of control may not be high enough to prevent economic pest damage as demonstrated by negative results with mass release of Trichogramma egg parasites for control of tortricids in orchards. Suitability of the orchard habitat is recognized as crucial to the success of individual parasitoids. Key requirements are adequate populations of the pest(s) and/or alternative hosts, suitable shelter, overwintering sites or food sources and avoidance of harmful effects of pesticides. Many species are highly sensitive to broad-spectrum insecticides, especially in the adult life-stage. Avoiding the harmful affects of insecticides is crucial to successful exploitation. The use of insecticides needs to be avoided, either altogether or at crucial times in the parasitoids' life cycle, or less harmful alternatives need to be used. Numerous parasitoids could potentially be exploited as biological control agents but hitherto have received little attention because little is known about them and/or because they are sensitive to broad-spectrum pesticides and are thus virtually absent from commercial orchards. The aim of future studies should be to develop effective strategies for establishing equilibria between important pests and their parasitoids, with pest damage rarely exceeding the economic threshold.     

小苍兰试管球茎诱导及开花研究

小苍兰茎尖在含３．０ｍｇ／ＬＢＡ＋０．２ｍｇ／ＬＮＡＡ的ＭＳ培养基上,可诱导出许多侧芽。侧芽转移至０．５ｍｇ／ＬＩＢＡ＋０．５％活性炭的ＭＳ培养基,在１３＋２℃温度下培养１个月能诱导成小球茎。经电泳鉴定,试管球茎的可溶性蛋白质谱带与常规球茎的谱带完全相同。试管球移栽后约经７个月即可开花,其观赏性状完全稳定,花后成熟的大球达到商品球标准,可直接用于切花生产。     

Fungal functional diversity inferred along Ellenberg's abiotic gradients: Palynological evidence from different soil microbiota

The aim of this paper is to analyse whether the functional diversity of the fungal community follows the environmental gradients as much as vascular plants. After determination of the Ellenberg's indicator values on the basis of 602 cormophyte species occurring in 110 permanent plots across Central Europe, the relation between soil fungi and the abiotic factors as defined by Ellenberg's indicators has been evaluated. The palynological assessment proves that not the fungal occurrence, but the concentration of fungal remains is the most appropriate tool to unravel causal links between the belowground microflora and the soil abiotic factors. The analyses show a striking dichotomy within the fungal community. First, the logarithms of fungal diversity and hyphal density show close but opposite relationships with light, moisture, soil reaction and nitrogen availability. Second, fungal functional groups show parallel, decreasing trends for soil reaction and nitrogen availability. Aside from the mycorrhizal network as a whole (ericoid, EM and AM), we demonstrate that the degree of ecological information supplied by the different trophic levels (litter-related fungi, fimicolous fungi, wood-related fungi and strictly ericoid mycorrhizal fungi) is much greater than expected from previous studies.     

Convergent evolution and adaptive radiation of beetle-pollinated angiosperms

A literature review of 34 families of flowering plants containing at least one species pollinated primarily by beetles is presented. While the majority of species are represented by magnoliids and basal monocotyledons specialized, beetle-pollinated systems have evolved independently in 14 families of eudicotyldons and six families of petaloid monocots. Four, overlapping modes of floral presentation in plants pollinated exclusively by beetles (Bilabiate, Brush, Chamber Blossom and Painted Bowl) are described. Chamber Blossoms and Painted Bowls are the two most common modes. Chamber Blossoms, found in magnoliids, primitive monocotyledons and in some families of woody eudicots, exploit the greatest diversity of beetle pollinators. Painted Bowls are restricted to petaloid monocots and a few families of eudicots dependent primarily on hairy species of Scarabaeidae as pollen vectors. In contrast, generalist flowers pollinated by a combination of beetles and other animals are recorded in 22 families. Generalist systems are more likely to secrete nectar and exploit four beetle families absent in specialist flowers. Centers of diversity for species with specialized, beetle-pollinated systems are distributed through the wet tropics (centers for Brush and Chamber Blossoms) to warm temperate-Mediterranean zones (centers for Painted Bowls and a few Bilabiate flowers). It is unlikely that beetles were the first pollinators of angiosperms but specialized, beetlepollinated flowers must have evolved by the midlate Cretaceous to join pre-existing guilds of beetlepollinated gymnosperms. The floras of Australia and western North America suggest that mutualistic interactions between beetles and flowers has been a continuous and labile trend in angiosperms with novel interactions evolving through the Tertiary.     

Catechol-O-methyl transferase in mouse liver plasma membranes.

Catechol-o-methyl transferase is usually localized predominantly in the cytosol fraction of cells, but fractionation of mouse liver showed plasma membranes contain ～ 70% of the total enzyme activity and have a specific activity ～ 10x greater than the cytosol fraction. Treatment of the membrane fraction with Lubrol-PX solubilized 47% of the membrane protein and 95% of the enzyme activity. A comparison of Lubrol-solubilized enzyme and [³H]norepinephrine binding activities in a variety of experimental conditions suggest binding is not related to interaction with the active site of catechol-o-methyl transferase. Isoelectric focusing of solubilized membrane proteins showed the enzyme has an isoelectric pH of 4.5-4.8.     

Linear aggregation and the turbidimetric lag phase: type I collagen fibrillogenesis in vitro.

Using classical light scattering theory it is shown that the turbidimetric lag phase is a property of macromolecular systems that form linear aggregates during the initial period of self-assembly. This analysis and previous observations on Type I collagen suggests that initiation occurs by the conversion of single molecules into linear dimers in which neighboring molecules are staggered by 4·0 D (D = 67 nm). Linear.growth of dimers occurs by 4 D addition of either single molecules or linear aggregates until the aggregate is about 60 to 70 molecules long. Linear growth appears to involve charged binding sites in the amino and carboxy termini. The same sites have been shown to be involved in crosslink formation and in the attachment of disaccharides.Lateral growth occurs via the rapid formation of several discretely sized intermediates which lead to the formation of narrow fibrils ～ 25 nm wide. Narrow fibrils individually wrap around each other increasing the diameter to 100 nm or greater.     

利用固化技术生产麦花啤

麦花啤是一种发酵饮料,深受广大消费者欢迎,但是旧生产工艺是自然发酵,即不能保证产品质量,而且又由于杂菌污染,而导致爆瓶,甚至伤人,后果严重,用固化酵母新技术生产麦花啤,完全克服了上述问题,结果十分令人满意。