黑土中大豆连作障碍诊断系统的建立初报——主要障碍因子的确立

黑龙江省黑土区大豆种植连作现象严重,造成生长不利、产量降低,初步诊断主要障碍因子是孢囊线虫增加,根腐病加剧,土壤中大、中、微量元素含量不平衡.另外,农民施肥不科学也是影响大豆产量的一个主要因素.为此,建立了大豆连作障碍诊断系统,找出了主要障碍因子.     

采用计算机视觉进行棉花虫害程度的自动测定

采用计算机视觉技术，根据棉花叶片的孔洞及叶片边缘的残缺，来测定棉花虫害的受害程度。该方法应用局部门限法完成图像与背景的分割；用高斯拉普拉斯算子，进行棉花图像的边缘检测；利用边缘跟踪算法确定棉叶中的孔洞；利用膨胀算法确定叶片边缘的残缺。实验结果表明，该方法可有效的测定棉花虫害的受害程度，其测定误差小于0.05。     

Amplification facilitators and multiplex PCR: Tools to overcome PCR-inhibition in DNA-gut-content analysis of soil-living invertebrates

Polymerase chain reaction (PCR) can be used to detect prey within the gut contents of predators and allows specific trophic interactions to be studied among soil-dwelling invertebrates which cannot be examined by other approaches. PCR-inhibitory substances, however, are commonly found in DNA prepared from soil organisms or from biological material contaminated with soil. This can lead to false-negative results and the risk of not detecting trophic connections or of underestimating predation rates in field studies. In the present study, we developed mitochondrial DNA markers to detect Amphimallon solstitiale (Coleoptera: Scarabaeidae) in the gut contents of invertebrate predators. Larvae of A. solstitiale can cause serious damage in grasslands, field crops, and forests by feeding on roots. Adequate methodologies to study predation on these pests are lacking, and their invertebrate predator guild is, therefore, barely known. To test the new molecular markers for prey detection, larvae and eggs of A. solstitiale were fed to Poecilus versicolor larvae (Coleoptera: Carabidae), which are abundant below-ground predators in grassland ecosystems. Unfortunately, even when specific DNA extraction and purification methods were used, DNA extracts from predators were of poor quality and not amplifiable by PCR; this yielded false-negative results and a dramatically lower prey-detection rate. We overcame PCR-inhibition by applying ?1.28 μg μl⁻¹ bovine serum albumin to the PCR reaction mix. This enabled us to detect A. solstitiale DNA within fed carabid larvae up to 48 and 40 h post-feeding for 127 and 463 bp sized DNA fragments, respectively. When single A. solstitiale eggs were consumed by the carabid larvae, predation could be verified in 100% of the predators within the first 8 h of digestion; some carabid larvae even tested positive 32 h after feeding. Moreover, by multiplexing primers targeting both prey and predator, we were able to simultaneously screen for prey consumption and check for co-purified PCR inhibitors. Sensitivity in prey detection was not reduced compared to singleplex PCR. We recommend the multiplex approach because it considerably reduces time and costs compared to singleplex assays. We also show that multiplex PCR not only detects specific prey, but also can identify the predator itself. This allows the identification of taxa which are difficult or not identifiable based on morphological characters, such as soil-dwelling predatory beetle larvae.     

红壤旱地不同农田生态系统结构对玉米病虫害的影响

红壤旱地不同农田生态系统结构对玉米病虫害的影响研究表明,间作、套种可减轻玉米病虫害。晚玉米间作绿豆,玉米纹枯病和玉米小斑病的发病率和病情指数均低于清种玉米。玉米蚜、玉米螟、黄足蠼螋和出尾虫是玉米生长中后期的主要害虫,尤其是玉米螟、黄足蠼和出尾虫直接危害穗部,对产量影响较大。油菜||紫云英／玉米／玉米||绿豆模式玉米害虫种类和数量少,害虫天敌总数多,主要玉米害虫危害率低,适于红壤旱地推广应用。     

农业病虫害预测预报专家系统平台的开发

详细介绍了农业病虫害预测预报专家系统平台的设计与开发，包括系统的整体结构与功能设计、系统知识库的设计与知识组织模型、系统各功能模块的设计及系统的特点等。系统主要由专家知识库、系统推理机、预测预报模块、知识库管理模块、案例库管理模块和预测结果解释模块等构成，以数据库形式来存放有关的专家知识，共定义10个数据表，各表间形成了特定的关联关系，使得表中所包含的有关知识描述、特征临界值、生成的判别条件及发生等级间构成一种网状模型。系统采用了基于专家知识的前向型推理与基于案例的推理(Case-Based Reasoning, CBR)相结合的方式进行预测推理。各模块的用户界面采用“向导”或其它提示方式引导用户完成专家知识库的维护、用户数据输入、推理确认、病虫害预测预报结果显示、案例库管理(包括案例确认、补充信息及案例统计)及预测结果解释等操作。系统具有开放、自学习、易操作等特性，可广泛应用于农业、林业等病虫害预测预报专家系统的构建。     

辽宁省地下害虫地理区划

根据地势、地形、植被、气候条件以及地下害虫种类组成等方面的差异，将辽宁的地下害虫划分为3个区，6个亚区，即东部山区（长白山地亚区、半岛丘陵亚区）、中部平原区（北部波状平原亚区、南部平原亚区）及西部低山丘陵区（风沙亚区、低山丘陵滨海亚区）；记述了各亚区的地下害虫种类与组成．     

南方花卉病虫害多媒体课件制作

鲜花是大家日常生活中所不可缺少的，然而花卉的病虫害是危及花卉生产的一个大问题。利用Flash MX软件制作的南方花卉病虫害多媒体教学课件，具有操作容易，简易明了，更新方便，画质清晰等特点，既适用于课堂教学，也可以用于对相关人员进行专题讲座的演示和网络远程教学，将能促进南方花卉病虫害知识的普及，促进城市现代化建设的发展。     

尖把梨盛果期低产园优质高产栽培技术

尖把梨风味浓郁,口感极佳,品质上等。因管理不当,导致盛果期树势过旺,树形紊乱,通透不良,产量品质低劣。经3年科学管理,各项指标明显改善,产量产值达到生产要求。栽培技术要点是,合理进行骨干枝改造,细致进行枝组枝条修剪,选择适合的授粉品种高接,适时适量疏果,有效防治病虫害和科学改土、施肥、灌水。     

硫酰氟对储粮害虫活性及残留量实验研究

用硫酰氟熏蒸处理储粮害虫,对储粮害虫活性及硫酰氟的残留量进行了试验研究。在温度15~10℃下密闭熏蒸16 h,供试虫种的致死中量为:锯齿谷盗LD50=1.4125 g/m3,谷蠹LD50=1.972 g/m3,玉米象LD50=2.512 g/m3,甜食虫LD50=3.715 g/m3,赤拟谷盗LD50=7.446 g/m3。混入二氧化碳能使硫酰氟分散增匀,促进药剂渗透,有增效作用。建议在开拓硫酰氟应用于储粮时,5~10 g/m3剂量硫酰氟混入二氧化碳14~16 d,处理后的含氟量均低于国家规定的允许量。     

大通地区害鼠害虫毒草及危害现状

通过对大通县草原鼠虫害及毒草分布情况和危害程度调查，结果表明：大通县草原鼠害发生面积为40300hm2，危害面积为33290hm2；害虫发生面积为23780hm2，危害面积为21340hm2；毒草发生面积为8330hm2，危害程度高达6．02％。