植物园植物资源保育之创新

植物资源是植物园存在和发展的基础,植物资源保育是植物园最基本的工作。以往的植物资源保育工作主要包括植物资源日常管护、繁殖和资源保育研究,此模式的局限性随着植物园的发展或植物园面临越来越多的挑战而日显突出。植物资源保育之创新,首先是拟保育资源的系统性选择,其次是已保育资源的运用,包括植物资源的基础研究与应用研究、开发与推广应用以及科普利用。     

成都市温江区不同栽植年限园林植物土壤动物群落特征

对成都市温江区不同栽植年限园林植物土壤动物群落特征进行调查分析,4次取样共捕获土壤动物10258只,隶属26目78科。不同园林植物土壤动物类群数存在显著差异,基本以红花檵木、银杏样地最高,结缕草样地最低,各栽植年限土壤动物类群数均低于周边农田和撂荒地;桂花样地土壤动物类群数、个体数受季节变化影响较小,其余样地土壤动物个体数具有明显的季节动态,而类群数随季节变化不显著;土壤动物多样性指数受园林植物种类及栽植年限影响,银杏样地土壤动物密度-类群指数(DG)及Margalef丰富度指数(D)和结缕草样地土壤动物Shannon多样性指数(H)及D指数均随栽植年限增加而显著降低,桂花样地土壤动物DG指数、D指数则随栽植年限增加显著升高,红花檵木样地土壤动物多样性各指数随栽植年限增加未表现规律性变化,其中土壤动物DG、D、H指数各栽植年限基本以桂花样地最低;聚类及典型关联分析(CCA)表明,园林植物种类对样地生境的影响大于栽植年限,土壤动物对不同生境因子响应不同,其中速效P、土壤pH对土壤动物影响较大。土壤动物群落特征受园林植物种类、栽植年限及栽培管理方式的影响,而过度人为干扰、单一植物连栽会对土壤动物产生不利影响,并可能导致土壤地力衰退。     

华南地区8种常见园林地被植物抗旱性比较研究

以华南地区8种常见园林地被植物为研究对象,在温室内设置盆栽控水试验,分组测定各参试植物的永久萎蔫率,叶片失水率、相对含水量、相对电导率、可溶性糖、脯氨酸以及丙二醛含量等生理生化指标,并用隶属函数法对其抗旱性进行综合评价。结果表明:(1)植物的永久萎蔫率和叶片失水率以鹅掌藤、白蝴蝶相对较低,其植株表现出较强的抗旱性。(2)随着持续干旱时间的延长,8种地被植物的叶片相对含水量呈不同程度下降趋势;叶片相对电导率、MDA含量均有不同程度升高;叶片可溶性糖和脯氨酸含量的变化趋势不一。(3)3种木本植物的抗旱性强弱依次为鹅掌藤>红花龙船花>红背桂,5种草本植物依次为水鬼蕉>蚌兰>白蝴蝶>葱兰>大叶红草。研究表明,植物的永久萎蔫率、叶片失水率、相对含水量、相对电导率、丙二醛含量与其实际抗旱性密切相关,可作为评价园林地被植物抗旱性的有效指标。     

茶叶中总硒含量及其影响因素的研究

茶叶中硒素总量测定结果表明：土壤含硒量的高低是直接影响茶叶中硒的总量。茶树根、茎、叶、果中均有硒元素,叶片是茶硒积累的主要器官,尤其是老叶,其含量是嫩叶的几倍．茶树品种间含量的差异显著,最大差异达10倍以上．毛茶加工的成品茶含硒量受加工技术措施影响较大,其不同等级的含硒量与级别没有线性关系．     

Divergence in style length and pollen size leads to a postmating‐prezygotic reproductive barrier among populations of Silene latifolia

A central tenet of speciation research is the need to identify reproductive isolating barriers. One approach to this line of research is to identify the phenotypes that lead to reproductive isolation. Several studies on flowering plants have shown that differences in style length contribute to reproductive isolation between species, leading us to consider whether style length could act as a reproductive barrier among populations of a single species. This could occur if style length varied sufficiently and pollen size covaried with style length. Populations of Silene latifolia exhibit variation in flower size, including style length, that is negatively correlated with annual precipitation. We show that this divergence in style length has a genetic basis and acts as a reproductive barrier: males from small‐flowered populations produced relatively small pollen grains that were poor at fertilizing ovules when crossed to females from large‐flowered populations, leading to a significant reduction in seed production. Manipulating the distance pollen tubes had to travel revealed that this failure was purely mechanical and not the result of other incompatibilities. These results show that style length acts as a postmating‐prezygotic reproductive barrier and indicate a potential link between ecotypic differentiation and reproductive isolation within a species.     

The effect of a chemical deterrent, released from the frass of caterpillars of the garden pebble moth, on cabbage root fly oviposition

The cabbage root fly, Delia radicum (L.), was deterred from laying eggs on cauliflower plants that had been sprayed with a suspension of the frass of caterpillars of the garden pebble moth, Evergestis forficalis (L.). Polar extracts of the frass deterred oviposition irrespective of the cruciferous plant species on which the caterpillars had been feeding. Non-polar extracts of the frass had no effect. Spraying plants with macerates from Brassica leaves stimulated fly oviposition whereas spraying plants with macerates from garlic mustard leaves deterred fly oviposition. Macerates from the leaves of all other plants tested had no effect. In field experiments the deterrent effect persisted 2–3 days after leaves were sprayed with frass extracts. Plants infested with feeding caterpillars and contaminated with only a few discrete frass pellets were as deterrent to the fly as those sprayed with frass suspensions.

---

Résumé D. radicum a évité de pondre sur des pieds de chou-fleur, qui avaient été pulvérisés avec une suspension d'excréments d'E. forficalis. Les extraits polaires de ces excréments empêchent la ponte quelle que soit l'espère de crucifère sur laquelle les chenilles se sont alimentées. Les extraits non polares sont sans effet. Dans la nature, l'action dissuadante persiste 2 à 3 jours après la pulvérisation des feuilles avec les extraits d'excréments. La pulvérisation tous les deux jours a maintenu l'action dissuadante. Des plantes contaminées par des chenilles en train de s'alimenter et souillées par quelques crottes sont aussi dissuadantes pour la mouche que celles pulvérisées avec une suspension d'excréments.

     

Effect of green tea polyphenols on angiogenesis induced by an angiogenin-like protein

Angiogenesis is a fundamental process by which new blood vessels are formed. The angiogenesis process is induced by several growth factors. Among them angiogenin is the most potent blood vessel inducer known. In this paper, we have investigated the effect of green tea polyphenols, mainly the catechins, on an angiogenin-like protein induced angiogenesis process. The angiogenin-like protein was isolated from goat serum and the effect of green tea components was tested by the chicken chorioallantoic membrane (CAM) assay. The results show that green tea components are capable of reducing the vascularization on CAM that is induced by the angiogenin-like protein.     

Genomic Shifts,Phenotypic Clines,and Fitness Costs Associated With Cold Tolerance in the Asian Tiger Mosquito

Climatic variation is a key driver of genetic differentiation and phenotypic traits evolution, and local adaptation to temperature is expected in widespread species. We investigated phenotypic and genomic changes in the native range of the Asian tiger mosquito, Aedes albopictus. We first refine the phylogeographic structure based on genome-wide regions (1,901 double-digest restriction-site associated DNA single nucleotide polymophisms [ddRAD SNPs]) from 41 populations. We then explore the patterns of cold adaptation using phenotypic traits measured in common garden (wing size and cold tolerance) and genotype–temperature associations at targeted candidate regions (51,706 exon-capture SNPs) from nine populations. We confirm the existence of three evolutionary lineages including clades A (Malaysia, Thailand, Cambodia, and Laos), B (China and Okinawa), and C (South Korea and Japan). We identified temperature-associated differentiation in 15 out of 221 candidate regions but none in ddRAD regions, supporting the role of directional selection in detected genes. These include genes involved in lipid metabolism and a circadian clock gene. Most outlier SNPs are differently fixed between clades A and C, whereas clade B has an intermediate pattern. Females are larger at higher latitude yet produce no more eggs, which might favor the storage of energetic reserves in colder climate. Nondiapausing eggs from temperate populations survive better to cold exposure than those from tropical populations, suggesting they are protected from freezing damages but this cold tolerance has a fitness cost in terms of egg viability. Altogether, our results provide strong evidence for the thermal adaptation of A. albopictus across its wide temperature range.     

Soil–Plant Transfer Factors for Garden Produce from Contaminated Soils: Site Specific versus Generic Estimates for As and Pb

Using publicly available data for contaminated sites, regression relationships between As or Pb concentrations in co-located soils and leaf, root, and fruit vegetables, were developed. The improvement of these regression relationships by additional independent variables known to influence bioavailability of these trace elements in soil (soil pH, available phosphorous, Fe oxide, total Fe, and organic carbon content) was tested. Soil pH, but not plant-available P, decreased unexplained variation in the model for As in leafy vegetables. Iron oxide concentration in soil reduced unexplained variability in As concentrations in root vegetables, but with a positive coefficient thus contradicting its anticipated role as a competitor for As uptake by plants. None of the soil characteristics beyond total Pb concentration reduced variability observed in Pb concentrations in leafy or root vegetables, and there was no model that predicted Pb concentrations in fruit. Predictions of tissue concentration from single-value Plant-Uptake Factors (PUFs) for As in leaf and root vegetables, and for Pb accumulation in root vegetables, deviated more from the observed values than predictions from the regression relationships. The FW PUF determined from this study was within an order of magnitude of that used by the United Kingdom for development of generic soil quality values.     

绿茶抗氧化剂成分抑制突变作用的初步研究

绿茶水溶性提取物及茶叶中抗氧化剂成份具有明显的抑制AFB_1及Bap诱导的鼠伤寒沙门氏菌回复突变作用。这种抗氧化剂成份还可以抑制AFB_1和Bap诱导的V79细胞基因正向突变,以及AFB_1诱导的V79细胞SCE和染色体畸变。本实验结果提示,绿茶中抗氧化剂成份可能对AFB_1及Bap的致癌性具有抑制作用。本文就茶叶抗氧化剂抑制突变的可能机制进行了初步讨论。