关于农药混用评价标准的讨论

本文对混剂的评价方法和评价标准进行了介绍和比较, 建议采用共毒系数小于５０ 为拮抗作用、＞ １５０ 为增效作用的评价标准。     

玉米抵御鞘腐病菌侵染的生理机制

为深入探讨玉米抗鞘腐病的机制,以高抗品种浚单20、9058及中抗品种郑单958、郑58为材料,测定了接种层出镰孢后苯丙氨酸解氨酶、过氧化物酶、超氧化物歧化酶、多酚氧化酶、过氧化氢酶、木质素含量及抗病相关基因PR-1、PR-2a、LOX、MPI和GAPc的表达量.结果显示:接种后不同抗性材料叶鞘部位的防御酶活性均上升,多数在6h达到峰值,且高抗材料酶活性增幅较大;供试材料的木质素含量均上升,且高抗材料的含量高于中抗材料;PR-1、MPI、GAPc和PR-2a等抗病相关基因的表达呈上升趋势,而LOX的表达量变化趋势不明显.研究表明玉米对鞘腐病的抗性与防御酶活性、木质素含量及其抗病相关基因的表达量呈正相关.     

河北省二点委夜蛾发生世代研究初报

二点委夜蛾[Athetis lepigone(Mschler)]是2005年河北省首次发现报道的夏玉米苗期的新害虫,危害日趋严重。本文通过分析近年来对二点委夜蛾成虫的监测数据,研究其发生世代。结果表明:二点委夜蛾在河北省每年发生4代。4-5月为越冬代成虫期,6-7月上旬为1代成虫期,7月中旬-8月上旬为2代成虫期,8月中旬-9月下旬为3代成虫期。其中1～2代成虫蛾量大,蛾峰明显,以第2代幼虫为害玉米苗最为严重,越冬代成虫和第3代成虫蛾量较少,蛾峰不太明显。     

利用性诱剂防治花生田暗黑鳃金龟的研究

为明确暗黑鳃金龟(Holotrichia parallela Motschulsky)性诱剂对成虫的引诱效果及对幼虫虫口密度的降低作用,在全国主要花生产区开展了田间诱捕试验,调查诱捕成虫数、幼虫减退率及对花生的保果效果。结果表明:一台诱捕器一天内诱到的最大成虫数为977头;幼虫减退率最高可达78.8%,保果效果最高可达68.6%。表明暗黑鳃金龟性诱剂对成虫有很强的引诱效果,并能明显减轻幼虫为害。     

拮抗细菌Bs-0728对板蓝根根腐病的防治作用

［目的］ 筛选对板蓝根根腐病有较强拮抗作用的生防菌株。［方法］ 采用平板对峙法对137个板蓝根根际土壤样本中分离到的201株拮抗细菌进行测试。［结果］ 筛选出1个对板蓝根根腐病菌有强烈抑制作用的菌株Bs-0728。结合显微镜观察确定Bs-0728菌株对板蓝根根腐病的主要致病菌茄腐镰刀菌（Fusarium solani）菌丝生长有较强的抑制作用,导致菌丝生长畸形,弯曲,部分细胞膨大。田间试验结果表明,Bs-0728的发酵液田间防效达72.97%,且增产86.26%。经形态观察、生理生化反应及16S rDNA 序列分析,初步将此拮抗细菌鉴定为枯草芽胞杆菌Bacillus subtilis。［结论］ 枯草芽孢杆菌Bs-0728菌株是一株很有应用前景的生防菌株。     

Biological diversity of citrus tristeza virus (CTV) isolates in Spain

A survey of citrus tristeza virus (CTV) isolates was carried out in most citrus-growing areas in Spain. Twenty-two isolates were selected by geographical origin, cultivar of source tree, and symptoms observed on the host or in preliminary tests, and were biologically characterized.
A wide range of variation in transmissibility by aphids and symptom intensity on nine different indicator species or scion-rootstock combinations was observed among CTV isolates. Mexican lime. Citrus macrophylla , and to a lesser extent citron were the most useful hosts for characterizing these isolates, and leaf symptoms and stem pitting were the most discriminating traits. Positive correlation was observed between symptoms induced on Mexican lime and C. macrophylla , but not between the symptoms induced on these indicators under greenhouse conditions and the homologous symptoms on plants grown in the screenhouse. Some of the traits studied enabled us to establish relatively well-defined groups of isolates, but in most cases a continuous range of variation was obtained and no clear group could be defined.     

Antifeedant and sublethal effects of imidacloprid on Asian citrus psyllid,Diaphorina citri

BACKGROUND: Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, transmits the causal bacteria of the devastating citrus disease huanglongbing (HLB). Because of the variation in spatial and temporal uptake and systemic distribution of imidacloprid applied to citrus trees and its degradation over time in citrus trees, ACP adults and nymphs are exposed to concentrations that may not cause immediate mortality but rather sublethal effects. The objective of this laboratory study was to determine the effects of sublethal concentrations of imidacloprid on ACP life stages. RESULTS: Feeding by ACP adults and nymphs on plants treated daily with a sublethal concentration (0.1 µg mL^?1) of imidacloprid significantly decreased adult longevity (8 days), fecundity (33%) and fertility (6%), as well as nymph survival (12%) and developmental rate compared with untreated controls. The magnitude of these negative effects was directly related to exposure duration and concentration. Furthermore, ACP adults that fed on citrus leaves treated systemically with lethal and sublethal concentrations of imidacloprid excreted significantly less honeydew (7–94%) compared with controls in a concentration‐dependent manner suggesting antifeedant activity of imidacloprid. CONCLUSIONS: Sublethal concentrations of imidacloprid negatively affect development, reproduction, survival and longevity of ACP, which likely contributes to population reductions over time. Also, reduced feeding by ACP adults on plants treated with sublethal concentrations of imidacloprid may potentially decrease the capacity of ACP to successfully acquire and transmit the HLB causal pathogen. Copyright © 2009 Society of Chemical Industry     

安徽省农药管理和使用现状与建议

介绍了安徽省农药行业发展现状,农药管理和合理使用的主要做法,分析了当前存在的主要问题,提出了促进全国农药管理和使用的建议.     

小麦秆锈菌新小种Ug99及其对我国的影响分析

Ug99(TTKS)是1999年在乌干达首次发现的对最重要小麦抗秆锈病基因Sr31有强毒力的秆锈菌新小种。大量证据显示:该小种不仅具有极其特殊的毒力组合而且传播十分迅速,除在中非乌干达、东非肯尼亚、埃塞俄比亚、苏丹流行外,Ug99现已越过红海、传到了阿拉伯国家也门,以及巴基斯坦的沿海地区,越来越逼近我国。Ug99堪称我国的超毒小种,我国最典型的秆锈菌小种只能分别克服或Sr5或Sr9 e或Sr11单基因抗性,而Ug99不仅具有Sr5、Sr9 e、Sr11的联合毒力,而且还具有Sr21、Sr31、Sr38的联合毒力,而我国从未有小种能克服后者的抗性。1B/1L(含Sr31)易位系曾是我国使用的重要秆锈抗源,必对Ug99高度脆弱,我国118份小麦品种在KARI的测定结果表明,高感品种频率98.3%。一旦Ug99入侵我国,其他流行条件也完全具备。因此,充分作好防范Ug99流行的准备十分必要。     

植原体基因组学研究进展

植原体（phytoplasma）是一类重要的植物病原细菌, 可经叶蝉、飞虱等昆虫介体传播, 感染1 000多种植物, 产生丛枝、黄化、韧皮部黑斑坏死等症状, 给农业、林业生产带来巨大的损失。本文对植原体基因组学研究的历史、现状及当前植原体效应蛋白等方面的研究进展进行了综述。