球孢白僵菌对马铃薯块茎蛾的毒力及其与常用农药的生物相容性测定

室内测定了从云南分离的7株球孢白僵菌对马铃薯块茎蛾幼虫的毒力,结果表明,在接菌孢子浓度为10⁵个/mL和10⁷个/mL下,接种后7d马铃薯块茎蛾幼虫累积死亡率分别为23.3%～70.0%和33.3%～86.7%,添加吐温80的清水对照死亡率仅为3.3%。筛选出毒力较高的Bb7001、Bb7004、Bb8001 3个菌株,其中菌株Bb8001对马铃薯块茎蛾幼虫的毒力最高,在孢子浓度1×10⁵、1×10⁷个/mL下,第7天的累计死亡率分别为70.0%和86.7%,其毒力回归方程Y=0.366X+3.409(R=0.956),剂量效应LC₅₀=2.24×10⁴个/mL,孢子浓度10⁷个/mL下的LT₅₀为4.3d。测定了毒力较高的菌株与12种农药的生物相容性,结果表明在供试农药推荐用量及其101、00倍稀释液下,球孢白僵菌Bb7001、Bb7004、Bb8001的3个菌株孢子在含所选农药的营养液中生物相容性良好的农药有:苏云金芽孢杆菌可湿性粉剂(Bt)、10%吡虫啉可湿性粉剂、2.5%菜喜悬浮剂及松毛虫病毒可湿粉剂,可配伍使用;而阿维菌素、农安、卡死克、抑太保对球孢白僵菌有很强的抑制作用,应避免配伍使用。     

不同温度下新蚜虫疠霉对桃蚜的毒力测定

在15、18、21、25、28℃温度下,将新蚜虫疠霉应用孢子浴法对1～2龄桃蚜进行毒力测定,各处理温度分别设10个剂量,每剂量处理蚜虫60～120头,逐日观察记载蚜虫死亡数量。结果表明,新蚜虫疠霉具有较强杀蚜虫特性,其致病性在25℃时达最佳效果。接种后的前2d为新蚜虫疠霉的潜伏期,接种后3～4d为对桃蚜的致死高峰期。在温度15、18、21、25、28℃下,接种60min后,新蚜虫疠霉对桃蚜的LT₅₀值分别为3.0、3.7、2.8、2.53、.9 d。     

植物对虫害的系统获得性抗性及抗虫与抗病信号途径间的相互作用

受病原体感染后,植物会获得一种持久广泛的抗性,称为系统获得性抗性,受到昆虫侵害时也会获得类似的系统获得性抗性.植物系统抗虫与抗病信号分子不同,前者是茉莉酸(JA)、甲基茉莉酸(Me-JA)或系统素,而后者是水杨酸(SA).SA介导的系统抗病信号途径与JA等介导的系统抗虫信号途径并非完全独立,而是存在所谓的"交叉对话",但"交叉对话"结果是相互促进还是抑制仍不清楚.植物系统抗性信号及其互作研究无疑会完善植物保护策略.     

检疫性有害生物发生程度评估方法的建立

通过对检疫性有害生物的发生危害情况进行综合分析研究,揭示了一套检疫性病、虫、杂草的发生面积统计标准以及发生程度4级评估方法,并利用该方法制作了2000～2002年广西23种检疫性有害生物疫情发生情况图.     

可视化技术在咸阳市水资源管理系统中的应用

运用现代数据库可视化管理技术,对长期以来咸阳市的水质、水量数据和资料进行系统分析和整理,提出了咸阳市水资源管理可视化的技术路线和系统设计方案,建立了咸阳市水资源可视化管理系统,为各职能部门提供科学管理手段,为技术人员进行决策提供科学依据,实现了水资源管理的规范化、高效化和快速化。     

红栀子主要害虫与天敌种类及田间种群动态研究

本研究系统调查了红栀子Gardenia iasmitmnides Ellis园中主要害虫与天敌种类及其田间发生动态，发现红栀子主要害虫有咖啡透翅天蛾Cephorwdes hylas L.日本龟蜡蚧Ceroplastes japoruicus Green，茶长卷叶蛾Homona magnanima Diakonoff,小灰蝶Deuabrix eryx L．；主要天敌有螟虫长距茧蜂Macrocentrus linearisNees，草蛉Chrysopa corneaSephens,赤眼蜂Trichogramma spp。田间种群动态调查结果表明：4、5月，几种害虫的发生量呈上升趋势，6、7月咖啡透翅天蛾的发生先上升后下降；而日本龟蜡蚧的发生则稳步上升；小灰蝶和茶长卷叶蛾先下降然后上升达到一个相对稳定水平。8月，除小灰蝶的发生是呈上升的趋势外．另外三种主要害虫的发生呈下降的趋势。草蛉在田间稳定增长，螟虫长距茧蜂的发生有波动，但总体上呈上升趋势。赤眼蜂在7月前有一定波动，7月后稳定上升。     

A viability study of Fallopia japonica stem tissue

Vegetative regeneration of intact and split nodes of Fallopia japonica (Houtt.) Ronse Decraene was the focus of this greenhouse experiment. Stem material, collected in May, July and September 1997, was cut into 40-mm-long sections and incubated on the surface of moist compost in a greenhouse. All samples showed some regrowth of buds and new shoots from both intact and split nodes in any season. A maximum number of 0.25 buds per intact node was recorded after 6 days in a spring experiment. The vegetative regrowth of shoots generally appeared after 1 week and increased over time with a maximum mean height of 77 mm after 27 days and a maximum number of 0.39 shoots per intact node after 13 days. Adventitious roots developed from both intact and split nodes during both summer and autumn experiments. From this study, a maximum of 90 stem tissue propagules per square metre of F. japonica stand has been estimated. If the plant is cut as part of a control programme, these propagules can produce shoots with growth rates of up to 2.9 mm per day with a good chance of the development of adventitious roots. This considerable potential for vegetative regeneration of stem tissue shows a clear need for guidelines on the safe management and disposal of F. japonica plant material.     

小菜蛾抗性稳定性及抗性治理对策研究

试验表明，福州地区田间小菜蛾已对有机磷、氨基甲酸酯及拟除虫菊酯产 生高抗性。脱离选择压力3代后，小菜蛾的抗性水平迅速下降。Bt预处理可提高抗性和敏感小菜蛾幼虫 对有机磷的敏感性，尤其对抗性小菜蛾增效极显著，对敏感小菜蛾AChE的 Ki值则影响不 大。据此提出在抗性治理中，应轮用或换用不同毒理机制的杀虫剂，且其间隔至少为2～3代。     

稻秆潜蝇综合防治技术研究

稻秆潜蝇是浙南山区水稻生产的重要害虫.通过推广薄膜育秧、绿肥田除草、选用抗性品种、实行健身栽培、生态控制等一系列综合防治技术,可达到经济有效的防治效果.在水稻整个生长期可减少用药1～2次,稻秆潜蝇穗被害率减轻41.03%,病虫害损失控制在3.6%以内,稻谷增产9.2%,稻田害虫天敌蜘蛛和黑肩绿盲蝽分别增加38.1%和26.3%,获得了明显的生态、经济效益.     

Efficacy of oxolinic acid and other bactericides in suppression ofErwinia amylovora in pear orchards in Israel

The efficacy of oxolinic acid (at 200 and 300 μg a.i./l) and of several antibiotic compounds (streptomycin sulfate at 100 μg a.i./l, glycocide B at 700 μg a.i./l, kasugamycin at 80 μg a.i./l and gentamicin sulfate at 30 and 60 μg a.i./l) againstErwinia amylovora, the causal agent of fire blight in pears, was evaluated in 43 orchard experiments in 1997–2000 in Israel. In addition to the above orchard experiments, the efficacy of the bactericides was tested in live experiments with artificial inoculation. Natural fire blight symptoms were observed in 16 of the 43 experiments; in 13 of them, disease intensity and its distribution among the experimental plots provided a basis for data analysis, leading to reliable conclusions concerning the efficacy of the tested bactericides. Oxolinic acid at 300 μg a.i./l was highly effective againstE. amylovora and reduced disease severity significantly in all experiments, as compared with the untreated plots; however, a concentration of 200 μg a.i./l was not effective in some cases. Among the tested antibiotics, only gentamicin sulfate was as effective as oxolinic acid. Results of the artificial inoculation experiments corroborated those obtained in the naturally infected orchards. The pre-infection activity of oxolinic acid was determined on blossom clusters that were sprayed with the bactericide before inoculation. Control efficacy on blossom clusters sprayed 1–4 days before inoculation ranged from 68% to 80%, a level which did not differ significantly from that observed on blossom clusters sprayed on the day of inoculation (80% control). The postinfection activity of oxolinic acid was determined on blossom clusters that were sprayed with the compound after inoculation. Oxolinic acid was as effective when applied 1 or 2 days after inoculation as when it was applied on the day of inoculation; however, application of the bactericide 3 days after inoculation no longer resulted in significant disease suppression. Oxolinic acid has been used commercially in Israel since 1998 with appreciable success. Contribution No. 533-00 from the Agricultural Research Organization