1％(噁)嗪草酮悬浮剂及与其他除草剂混用对机插稻田杂草的防效

1％(噁)嗪草酮悬浮剂45 g a.i./hm2处理对稗属杂草、千金子的防效均为90％以上.1％(噁)嗪草酮悬浮剂37.5 g a.i./hm2剂量与10％苄嘧磺隆可湿性粉剂22.5 ga.i./hm2混用,对稗属杂草、千金子、鳢肠、陌上菜、丁香蓼、草龙、田菁及异型莎草的防效均达到80％以上.1％(噁)嗪草酮悬浮剂37.5 g a.i./hm2剂量与10％双草醚可湿性粉剂30 g a.i./hm2混用对稗属杂草、千金子、鳢肠、陌上菜、丁香蓼、草龙、田菁、野荸荠、异型莎草的防效为88％～ 100％.1％(噁)嗪草酮45 g a.i./hm2剂量及37.5 g a.i./hm2剂量与10％苄嘧磺隆可湿性粉剂22.5 g a.i./hm2混用或与10％双草醚可湿性粉剂30 g a.i./hm2混用,对机插秧水稻安全.     

除草剂混配防除新疆南疆地区冬麦田杂草的药剂试验

10％苯磺隆WP 15 ～22.5 g a.i./hm2和5％唑啉草酯+炔草酸EC30 ～60 g a.i./hm2对冬小麦生长安全.其中,10％苯磺隆WP15 g a.i./hm2与5％唑啉草酯+炔草酸EC 45～ 60 g a.i./hm2对新疆南疆地区冬麦田阔叶杂草和禾本科杂草有较好的防除效果.采用二次稀释的方法,在冬小麦拔节前用药.     

5%嘧啶肟草醚乳油及与10%氰氟草酯乳油混用对旱直播稻田杂草的防除效果

5%嘧啶肟草醚乳油37.5、75 g a.i./hm2对稗属杂草、鳢肠、异型莎草及鸭跖草、丁香蓼、田菁等阔叶杂草的株防效均在80%以上,鲜重防效均在90%以上。5%嘧啶肟草醚乳油37.5 g a.i./hm2与10%氰氟草酯乳油112.5 g a.i./hm2混用可扩大杀草谱,提高对千金子的防效。     

湖南稻区稗草对二氯喹啉酸的抗性研究

利用整株测定法,测定湖南省主要稻区29个稗草生物型对二氯喹啉酸的抗性。结果表明,湖南省隆回县的生物型稗草对二氯喹啉酸最敏感,其EC50为76.388 3 g a.i./hm2,为敏感生物型。湖南省益阳芷湖口镇和湖南省长沙望城县(直播田)的生物型稗草对二氯喹啉酸的EC50分别为1 567.164 g a.i./hm2和2 477.542 g a.i./hm2,抗药性指数分别达20.52和32.43,表明这两种生物型稗草的抗药性处于高水平抗性。其中10个生物型稗草的EC50为155.931 8～375.114 g a.i./hm2,抗药性指数为2.02～4.91,表明这些生物型稗草已产生抗性。而其余16个生物型稗草的EC50为84.020 3～151.596 g a.i./hm2,抗药性指数为1.10～1.98,表明这些地方稗草的敏感性正在下降。     

4种药剂防治压砂西瓜田一年生杂草田间药效试验

采用田间小区试验方法进行4种药剂防除压砂西瓜田杂草田间药效试验.结果表明：50％敌草胺乳油1125 g a.i./hm2、72％异丙甲草胺乳油756 g a.i./hm2可有效防除压砂西瓜田的小画眉草、地锦草、狗尾草、小藜、虎尾草等.     

棒头草对16种夏熟作物田常用除草剂的敏感性

棒头草(Polypogon fugax)是我国夏熟作物田常见杂草,在一些地区已成为主要杂草。采用整株生物测定法研究了棒头草对夏熟作物田常用的5种土壤处理和11种茎叶处理除草剂的敏感性。结果表明,5种土壤处理剂对棒头草抑制地上部分生长90%的剂量(ED_(90))分别为:乙草胺(6.58 g a.i./hm~2)、氟乐灵(1 900.16 g a.i./hm~2)、吡氟酰草胺(120.22 g a.i./hm~2)、异丙隆(1 560.82 g a.i./hm~2)、绿麦隆(3 373.13 g a.i./hm~2)。乙草胺对棒头草的ED_(90)值远低于其推荐剂量,吡氟酰草胺对棒头草的ED_(90)值低于推荐剂量上限,然而氟乐灵、绿麦隆和异丙隆对棒头草的ED_(90)均高于推荐剂量上限,尤其是氟乐灵、绿麦隆。11种茎叶处理剂对棒头草的ED_(90)值剂量依次为:烯草酮(11.93 g a.i./hm~2)、甲基二磺隆(4.16 g a.i./hm~2)、啶磺草胺(12.62 g a.i./hm~2)、唑啉草酯(21.49 g a.i./hm~2)、精唑禾草灵(20.15 g a.i./hm~2)、精喹禾灵(6.77 g a.i./hm~2)、高效氟吡甲禾灵(81.82 g a.i./hm~2)、精吡氟禾草灵(32.63 g a.i./hm~2)、氟唑磺隆(176.44 g a.i./hm~2)、炔草酯(20.15 g a.i./hm~2)、烯禾啶(89.99 g a.i./hm~2),其中仅氟唑磺隆、高效氟吡甲禾灵对棒头草ED_(90)高于田间推荐剂量的上限。因此在播后苗前按推荐剂量使用乙草胺和吡氟酰草胺,以及除氟唑磺隆、高效氟吡甲禾灵外的9种茎叶处理剂均能有效防除棒头草,在实际应用中还需考虑对作物的安全性。     

胺苯·丙酯草醚油菜田应用技术研究

胺苯.丙酯草醚杀草谱较广,对移栽油菜田中禾本科杂草和阔叶杂草具有较好的防效,药效优于各单剂丙酯草醚和胺苯磺隆,与草除.精喹EC相当;在46.5~55.8 g a.i./hm2剂量下能有效防除禾本科杂草看麦娘、日本看麦娘,及阔叶杂草繁缕、牛繁缕、碎米荠、猪殃殃、野老鹳草,防效达到80%~90%,对稻槎菜防效一般(50%左右),对巢菜、草、棒头草和早熟禾基本无效;速效性一般,持效期在90 d以上;最佳施药时期为杂草1~3叶期的苗后早期;推荐使用剂量为46.5~55.8 g a.i./hm2,剂量在93 g a.i./hm2内对油菜安全。     

烯肟·戊唑醇20%悬浮剂防治早稻稻瘟病药效试验

试验结果表明,戊唑醇·烯肟菌胺20%悬浮剂对水稻稻瘟病有较好的防治效果,其中末次药后15d 150g a.i./hm2的防效达80.96%,与对照药剂三环唑20%可湿性粉剂300g a.i./hm2的防效相当,比对照药剂烯肟菌胺5%乳油150g a.i./hm2和戊唑醇25%可湿性粉剂150g a.i./hm2的防效高出5.67%和10.13%,且安全性好。     

几种除草剂对新疆移栽稻田杂草的防除效果

通过田间药效试验,筛选对移栽稻田杂草具有较好防效的除草剂,为科学、安全、高效应用除草剂提供依据。结果表明,750 g a.i./hm~2 40%五氟·丁草胺悬浮剂+67.50 g a.i./hm~2 30%苄嘧磺隆可湿性粉剂或525 g a.i./hm~2 500 g/L丙草胺乳油+67.50 g a.i./hm~2 30%苄嘧磺隆可湿性粉剂可用于移栽稻田土壤封闭处理,其对一年生杂草的株防效分别为83.90%、76.19%,鲜质量防效分别为94.29%、86.31%。针对以稗草发生危害为主的田块,可用90 g a.i./hm~2 10%精■·氰氟乳油、1 620 g a.i./hm~2 90%禾草丹乳油、24 g a.i./hm~2 25 g/L五氟磺草胺可分散油悬浮剂或120 g a.i./hm~2 100 g/L■唑酰草胺乳油+90 g a.i./hm~2 10%氰氟草酯乳油在苗后对茎叶进行喷雾处理,其株防效和鲜质量防效均在96%以上。     

16%草除灵·二氯吡啶酸·烯草酮SC防除移栽油菜田杂草的效果

16%草除灵·二氯吡啶酸.烯草酮SC对移栽油菜田一年生禾本科杂草及阔叶杂草的防效良好。在试验剂量180～480 g a.i./hm2下对移栽田油菜安全,不影响油菜的生长和发育。其适宜的施用剂量为240～480g a.i./hm2,施药适期为油菜3～5叶期、杂草3～4叶期,使用方法为叶面均匀喷雾。     

新疆奇台县近42a气候变化特征分析

根据新疆奇台县气象站的气温及降水资料,利用线性趋势函数及M ann-kendall突变检测法分析了该地区近42年的气候变化。结果表明:年平均气温与极端最低气温均呈上升趋势,而极端最高气温呈下降趋势;年降水量呈上升趋势。从季节变化来看,除夏季平均气温呈下降趋势,其它各季平均气温均呈上升趋势,其中以冬季增幅最大,秋季次之;各季降水均呈上升趋势,其中以夏季增幅最大,冬季次之。年平均气温未发生突变,而年降水量在1984年发生由少向多的突变。对气温和降水的异常分析得出,暖温年多发生在上世纪80年代后,冷温年多发生在上世纪60、70年代;多雨年主要在近20年,少雨年则多在上世纪60、70年代。此外,该县近42 a来增暖幅度小于全疆和北疆;增湿幅度大于全疆,小于北疆。     

昆虫组蛋白修饰的研究进展

组蛋白修饰作为表观遗传修饰的一种主要形式,对基因表达和表型调控具有重要作用.组蛋白修饰的N端尾区可通过乙酰化、甲基化、磷酸化等修饰来改变染色质的状态以及调控基因的表达.与脊椎动物相比,昆虫种类繁多,且有变态发育、表型复杂等特征,可以成为探索动物社会行为、发育调控和毒理作用等表观遗传基础的模型.本文总结了昆虫组蛋白修饰的...     

我国苜蓿病害研究进展

综述了我国苜蓿主要病害的分布和危害、病原学、发生规律、抗性种质材料的遗传筛选和鉴定及综合防治等方面的主要研究进展,并提出了今后的研究方向和发展目标。     

Major Changes in Fusarium spp. in Wheat in the Netherlands

The re-emergence of fusarium head blight throughout the world and especially in Western Europe prompted a survey of the situation in the Netherlands. To allow for a high throughput screening of large numbers of samples, a diagnostic PCR method was developed to detect the most common species of Fusarium occurring on wheat. Seven primer pairs were tested for their ability to identify isolates of Fusarium avenaceum, F. culmorum, F. graminearum, F. poae, F. proliferatum and Microdochium nivale var. majus and M. nivale var. nivale. Each primer pair only generated a PCR product with the corresponding Fusarium species and all PCR fragments had different molecular sizes. This allowed the generation of these amplicons using a mixture of all seven primer pairs. The robustness of this multiplex PCR encouraged us to screen a large series of isolates collected in 2000 and 2001. In both years 40 fields were sampled leading to a collection of 209 isolates from 2000 and 145 isolates from 2001. The results of the multiplex PCR demonstrated that F. graminearum was the most abundant species in the Fusarium complex on wheat in both years. This is in sharp contrast to reports from the 1980s and early 1990s, which found F. culmorum as the predominant species. Primers derived from the tri7 and tri13 genes, which are implicated in the acetylation and oxygenation of the C-4 atom of the backbone of the trichothecene molecule, were used to discriminate between deoxynivalenol and nivalenol (NIV) producers. The populations of F. culmorum and F. graminearum both showed a slight increase in NIV-producers in 2001.     

真菌甲硫氨酸生物合成途径研究进展

 甲硫氨酸是蛋白质的重要组分,同时还可通过生成S-腺苷甲硫氨酸（SAM）调控细胞内多种生理过程。本文根据酿酒酵母、粗糙脉孢菌和构巢曲霉3种模式真菌中甲硫氨酸生物合成的最新研究进展,勾画出真菌的甲硫氨酸合成途径,综述了该途径中关键酶的生物学功能,探讨了该途径的调控机制,为病原真菌甲硫氨酸合成的研究提供理论基础,同时为新杀菌剂的研发提供新思路。     

中国植物弹状病毒研究进展

弹状病毒含有单链负义RNA基因组,寄主范围比较广泛,能侵染无脊椎动物、脊椎动物以及植物等寄主,对人类的健康、农作物产量和自然生态系统造成严重威胁。植物弹状病毒主要根据复制场所分为细胞质弹状病毒属Cytorhabdovirus和细胞核弹状病毒属Nucleorhabdovirus,其基因组由单股负链RNA组成。此外,Dichorhavirus和Varicosavirus病毒属是两个新鉴定的植物弹状病毒属,其特征是具有二分体基因组。本文着重介绍危害我国农作物的几类植物弹状病毒,对它们的病理学、病害流行、基因组信息以及传播媒介进行概述,为中国植物弹状病毒病害的研究提供理论依据。     

Variability in initial spray deposit in apple trees in space and time

Variation in pesticide residues in space and time has not been investigated systematically in spite of the large variability found at single scales (e.g. between trees or orchards). Information on variability at different scales will support the development of sampling methods and more reliable prediction of residues. Experiments were conducted to quantify the spatiotemporal variability in initial spray deposit on apple leaves and fruit using a substitute tracer (zinc EDTA chelate). Five hierarchical spatial scales were defined as (1) between orchards, (2) between plots within an orchard, (3) between trees within a plot, (4) between zones within a tree and (5) between leaves/fruit within a zone. Similarly, two temporal scales were defined as (1) between applications within a single year and (2) between years. The initial zinc concentration was approximately log-normally distributed; the variability in initial deposit concentration was greater on leaves than on fruit. The average initial zinc deposition was significantly greater in the top and outside zones than in the middle zones within individual trees. The most important scale for driving residue variability is the within-zone unit-to-unit variation, contributing to 71 and 49% of the observed variability for leaf and fruit samples respectively. Variability at other scales was related to the variation in the tree architecture. The results indicated that stratified sampling on the basis of within-tree zone structures, with the effort focused on within-zone sampling, should be used for the determination of pesticide residues.