川西平原比利时杜鹃商品化盆栽技术

本文结合川西平原的气候特点和多年栽培实践,阐述了比利时杜鹃的生物学特性及生志习性,提出了特别是元旦、春节等节日用花的商品化盆栽技术要求．     

黄杜鹃叶提取物对桔二叉蚜的毒力及其毒理研究

黄杜鹃(Rhododendron molle)叶提取物对桔二叉蚜(Toxoptera aurantii)有较强的毒杀作用．黄杜鹃叶的乙醇总提物对桔二叉蚜无翅成蚜的半致死浓度(LC50)为1558mg/L在黄杜鹃叶提取物的4种萃取物中，乙酸乙酯萃取物对桔二叉蚜的毒力最强，其LC50为364mg／L，表明黄杜鹃叶含有的杀虫活性物质主要存在于乙酸乙酯萃取物中．实验表明，黄杜鹃叶乙酸乙酯萃取物对桔二叉蚜的乙酰胆碱酯酶(AchE)和羧酸酯酶(CarE)有一定的抑制作用．桔二叉蚜经10000mg/L的黄杜鹃叶乙酸乙酯萃取物溶液处理24h后，其体内的乙酰胆碱酯酶的活性为对照组的0．6543倍，羧酸酯酶的活性仅为对照组的0．4021倍．图2表4参10     

井冈山猴头杜鹃群落特征的研究

以井冈山猴头杜鹃（Rhododendron simiarum）群落5个样地调查资料为基础,对该群落的物种组成、区系成分、群落结构和物种多样性进行了研究,结果表明：群落有维管植物30科43属50种,其中蕨类植物有5科6属6种,裸子植物4科4属4种,被子植物21科33属40种。区系分析显示该植物区系起源古老,地理成分复杂,以热带性成分为主,温带性成分占有一定的比例。群落为复层异龄结构,猴头杜鹃、甜槠（Castanopsis eyrei）、福建柏（Fokienia hodginsii）、台湾松（Pinus taiwanensis）、薯豆（Elaeocarpus japonicus）和白豆杉（Pseudotaxus chienii）为群落的建群种。除Pielou指数外,群落物种多样性指数较低,各样地间多样性指数测值变幅较大;测度猴头杜鹃群落物种多样性时,各种多样性指数基本表现出相同的趋势;总体来看,猴头杜鹃群落物种多样性在群落不同层次的变化规律为：灌木层〉乔木层〉草本层。     

毛棉杜鹃地理分布及其开发利用

毛棉杜鹃为常绿灌木或小乔木,具有很高的观赏价值,介绍我国毛棉杜鹃的地理分布,生态学特性,阐述其优良特性以及开发利用的应用领域.结果表明:毛棉杜鹃具备优良的观赏特性和生态学特性,是一种极具发展潜力的园林植物材料.图2,表1,参8.     

Epidemiological risk assessment using linked network and grid based modelling: Phytophthora ramorum and Phytophthora kernoviae in the UK

We developed a stochastic simulation model incorporating most processes likely to be important in the spread of Phytophthora ramorum and similar diseases across the British landscape (covering Rhododendron ponticum in woodland and nurseries, and Vaccinium myrtillus in heathland). The simulation allows for movements of diseased plants within a realistically modelled trade network and long-distance natural dispersal. A series of simulation experiments were run with the model, representing an experiment varying the epidemic pressure and linkage between natural vegetation and horticultural trade, with or without disease spread in commercial trade, and with or without inspections-with-eradication, to give a 2 × 2 × 2 × 2 factorial started at 10 arbitrary locations spread across England. Fifty replicate simulations were made at each set of parameter values. Individual epidemics varied dramatically in size due to stochastic effects throughout the model. Across a range of epidemic pressures, the size of the epidemic was 5–13 times larger when commercial movement of plants was included. A key unknown factor in the system is the area of susceptible habitat outside the nursery system. Inspections, with a probability of detection and efficiency of infected-plant removal of 80% and made at 90-day intervals, reduced the size of epidemics by about 60% across the three sectors with a density of 1% susceptible plants in broadleaf woodland and heathland. Reducing this density to 0.1% largely isolated the trade network, so that inspections reduced the final epidemic size by over 90%, and most epidemics ended without escape into nature. Even in this case, however, major wild epidemics developed in a few percent of cases. Provided the number of new introductions remains low, the current inspection policy will control most epidemics. However, as the rate of introduction increases, it can overwhelm any reasonable inspection regime, largely due to spread prior to detection.     

淡黄杜鹃植物挥发油化学成分的研究

利用毛细管气相色谱保留指数定性、标准样品叠加和色谱质谱计算机联用技术,对淡黄杜鹃植物挥发油的化学成分进行了分离和鉴定,共鉴定出单萜烃１８个、倍半萜烃４１个,并测得了各化合物的相对含量,其主要成分是：β蒎烯、α蒎烯、乙酸冰片酯、柠檬烯、β榄香烯、香桧烯、香茅醇和月桂烯     

Controlling Rhododendron ponticum in the British Isles: an economic analysis

What resources should be committed to the control of invasive species? This study is based on a survey of nature conservation and forestry authorities, wildlife trusts and private landowners which investigated the extent of the ecological and economic impacts of the invasive non-native plant Rhododendron ponticum in the British Isles. There are data on 52,000 ha of land affected by R. ponticum, more than 30,000 ha of it in nature reserves. For nearly all nature reserves, displacement of native species and habitat changes were both reported. In 2001, respondents controlled 1275 ha of R. ponticum at a cost of pound 670,924. To test the optimality of this, we apply a model of social expenditure. The external costs of R. ponticum control are estimated from the probability that it will spread to contiguous sites and the damage done on invaded sites. These are then used to calculate the socially optimal level of expenditure on R. ponticum control, and the funding gap it identified by comparing the result with current levels of expenditure. The results suggest that a socially optimal level of control effort requires a significant increase in social funding for R. ponticum control, although the size of the increase varies between landholders.