Comparison ofPotato Virus Y andPlum Pox Virus transmission by two aphid species in relation to their probing behavior

Two different aphid species,Myzus persicae (Sulzer) andHyalopterus pruni (Geoffroy) (Homoptera: Aphididae), were used to analyze their ability to transmit two different potyviruses,Potato virus Y (PVY) andPlum pox virus (PPV), to pepper (Capsicum annuum) andNicotiana benthamiana plants, respectively. In parallel experiments,M. persicae consistently transmitted both viruses with high efficiency, whereasH. pruni always failed to transmit either virus. This is in contrast to previous reports describingH. pruni as a vector of these potyviruses. Different aphid probing behavior among individual aphids of each species was obtained in electrical penetration graph (EPG) experiments performed on pepper plants. This suggested thatH. pruni did not transmit these potyviruses due to behavioral differences during probing that impeded virus acquisition and/or inoculation. It was found thatM. persicae usually makes its first probe within the first 2 min, whereasH. pruni individuals remained for more than 10 min on the plant before starting to probe. Furthermore,M. persicae individuals displayed their first intracellular puncture during the first minute of probing whereasH. pruni needed ∼ 15 min to penetrate the cell plasmalemma with their stylets. In addition, intracellular stylet punctures occurred very frequently forM. persicae but was a rare event, never exceeding a single one, forH. pruni. The relevance of these findings for the epidemiological spread of potyviruses by different aphid species is discussed. http://www.phytoparasitica.org posting May 14, 2006.     

笼养东方白鹳越冬行为的研究

采用瞬时扫描法研究了东方白鹳（Cionia boyciana）越冬行为的活动节律和时间分配。结果表明：笼养东方白鹳在越冬期其活动有一定的节律性；越冬期的主要行为时间分配比例分别为静栖行为59．25％、避风行为11．17％、觅食行为6．41％、瞭望行为5．56％、理羽行为5．39％、游走行为5.14％；成年个体与幼雏在越冬行为时间分配上表现出了很大的差异；两性间越冬行为时间分配的差异不大；不同的温度、天气条件，对笼养东方白鹳越冬行为有影响。经观察发现：东方白鹳在高纬度北方地区越冬，对北方寒冷的天气有一系列的适应性，能在北方室外安全过冬。     

环境因素对丹顶鹤越冬行为的影响

丹顶鹤在盐城越冬期间各种环境因素对其行为都将产生一定的影响,对此我们进行了观察记录。该项工作主要用8×40、10×50双筒和20倍单筒望远镜实地观察、照相机摄影等直接记录丹顶鹤的各种行为；种群数量计算为直接计数法；气候因子则根据各级气象部门的预报结果,结合观察点温度计等手段测算。结果表明丹顶鹤越冬期间,气候因子的变化是对其行为产生直接影响的主要因素,温度、雨、雾、雪、风等发生大幅度变化时,都将导致越冬期丹顶鹤的行为发生相应的适应性变化,对迁徙行为的影响则更为明显。而食物和水源则通过气候因子的变化和安全度的影响再次反应到丹顶鹤的越冬行为中来。本文最后提出了减轻灾害性天气对丹顶鹤越冬行为的影响建议。     

丙谷胺对产蛋鸡摄食行为及内分泌的影响

选用35周龄伊莎蛋鸡8只,分别安装慢性颈静脉血管插管.实验采用自身对照法,对照期饲喂基础日粮,丙谷胺期在喂料前填喂丙谷胺.应用摄食行为计算机监测系统(FIDAS系统)记录各个实验期产蛋鸡喂料后4h内的采食行为数据,并测定有关血液生化指标.结果显示,实验期(填喂丙谷胺后)与对照期相比较,产蛋鸡午前(8:00～12:00)与午后(13:00～17:00)4 h内摄食量分别增加27.69%与30.41%(P＜0.05),摄食时间分别降低15.67%与3.75%,摄食餐数分别增加12.32%与27.2%(P＜0.05);血糖水平分别降低5.44%与18.03%(P＜0.01),瘦素水平分别升高2.59%与7.19%,胰岛素水平分别升高33.09%(P＜0.05)与24.5%(P＜0.05).提示丙谷胺能够促进蛋鸡摄食,并影响有关内分泌激素的水平.     

酸奶消费者购买行为的实证研究

以在校大学生问卷调查为例,应用联合分析法,运用极差分析、方差分析的统计学方法得出结论:价格是影响消费者酸奶购买行为的最显著因素;品牌和包装类型对酸奶购买的影响不相上下;净含量和保质期对消费者酸奶购买影响较小。乳品企业应针对不同的消费群体开发相应的产品、制定不同的市场营销策略。     

Recreational tree-climbing programs in a rural Japanese community forest: Social impacts and “fun factors”

We examined whether recreational tree climbing (TC) activities would have positive social impacts and rejuvenate an outdoor activity center and surrounding community forest in central Japan. Our case study comprised 3800 adults and children participating in TC activities at the Jyokoji Outdoor Activity Center (JOAC) in Seto, Japan. We focused on 1393 adult participants whom we considered to be the decision makers regarding family recreation, and we explored both the social impacts of TC and various factors that contributed to and distracted from the overall experience. Qualitative and quantitative data indicated that elements such as age, gender, tree preferences, tree appreciation, tree education, and technical instruction influenced the enjoyment of recreational TC and the positive effects on tree climbers. Overall, the climbing program had positive social impacts for the community forest and contributed to local conservation initiatives. Our case study suggests that other areas can benefit from incorporating TC programs into community forest planning to complement aesthetic, ecological, and restoration benefits and provide a new venue for recreation and conservation awareness.     

锡林郭勒盟北五旗近5年沙漠化过程及成因分析

本文在收集前人研究成果和野外调查的基础上,运用RS和GIS技术,以2000和2005年具有相同时相(秋季)的两期TM影像为信息源,对锡林郭勒盟北部五个旗、市地区的沙漠化土地进行了动态监测和分析。研究结果表明:近5a来研究区土地沙漠化总体呈上升扩展的趋势,5a来沙漠化土地面积增加了1366.057km2,其中轻度、中度、重度沙漠化土地面积分别增加:239.806 km2、1025.393 km2、850.396 km2,与此相反严重沙漠化土地面积减少了749.539 km2;地表疏松的沙物质,为土地沙漠化发展提供了丰富的物质基础,不合理的人类活动加速了沙漠化的发展。     

河西走廊资源型城市可持续发展与转型探讨

资源型城市作为一种重要的城市类型,对区域经济发展起着辐射和带动作用。本文以河西走廊的资源型城市(嘉峪关市、玉门市和金昌市)为例,以生命周期理论为指导,通过分析资源型城市发展面临的问题与困难,重点探讨干旱区资源型城市的可持续发展与转型,并提出了具体的对策建议。     

半干旱农牧交错区土壤养分空间变异特征分析——以内蒙古伊金霍洛旗为例

本文以伊金霍洛旗为研究区,通过GIS平台对土壤养分中的有机质、全氮、速效钾的空间插值方法进行了比较并得到了最优插值图。然后分析了该旗土壤养分的空间分布规律,为该地区的农业生产布局和生态环境建设提供了依据。通过比较后认为,在该地区有机质的空间插值用反距离权重法为好,而全氮和速效钾的空间插值以克吕格法的指数模型和高斯模型为好。地统计学分析结果表明:有机质、全氮和速效钾的变程分别为11853m,8932.2m和732.99m,全氮和速效钾具有中等空间相关性,而有机质空间相关性较弱。有机质含量普遍偏低,在91%的面积中有机质含量低于10g/kg,其相对高值区呈离散分布,可能与隐域植被的分布有关。全氮含量与有机质含量分布相似,在70%的面积中低于0.75g/kg,而速效钾含量中等,介于102.04-103.31mg/kg之间。在三个不同的景观亚区中,乌审凹地亚区的土壤养分状况较好,黄土丘陵亚区养分状况最差,毛乌素沙地亚区介于它们之间。     

卷叶螟绒茧蜂寄生棉大卷叶螟的行为及其与寄主密度的关系

卷叶螟绒茧蜂Apanteles derogatae Watanabe是棉大卷叶螟Sylepta derogata Fabricius幼虫期的一种重要内寄生蜂,对棉大卷叶螟种群有较好的控制作用。在实验室条件下,运用人工接虫观察法研究卷叶螟绒茧蜂对棉大卷叶螟幼虫的寄生行为。结果表明,该蜂搜寻寄主的时间平均为2．38 min,处理寄主的时间仅需0．86 min;寄生寄主的最适龄期为寄主2龄幼虫;对1龄幼虫的致死率达32%,但其寄生率仅为16%,其余16%的个体为穿刺致死。饲喂蜂蜜水能显著增加该蜂的产卵量,延长其产卵历期和增强其穿刺能力。寄生蜂的寄生能力与寄主密度的关系呈抛物线型:在寄生蜂均为16头/m~3雌蜂条件下,当寄主密度从80头/m~3增加到320头/m~3时,寄主的被寄生个体数随之增加,但当寄主密度超过320头/m~3后,寄主的被寄生个体数反而随寄主密度的上升呈下降趋势。