精恶唑禾草灵防除小麦田杂草看麦娘田间药效试验

精恶唑禾草灵属选择性、内吸传导型苗后茎叶处理剂,可用于阔叶作物如大豆、棉花、花生、油菜、蔬菜等防治一年生禾本科杂草,精恶唑禾草灵加入安全剂解草唑后,可增强小麦对精恶唑禾草灵的耐药性,用于小麦田防除一年及多年生禾本科杂草。为明确精恶唑禾草灵对麦田常见恶性杂草看麦娘的具体防效,笔者于2011年初,进行了精恶唑禾草灵防除冬小...     

抗性和敏感生物型菵草代谢精唑禾草灵的速度差异

为了测定菵草抗性生物型SD-04-SS和敏感生物型SD-12对精唑禾草灵代谢速度的差异,建立了精唑禾草灵及其主要代谢产物精唑禾草酸、6-氯苯并唑酮的高效液相色谱(HPLC)分析方法.结果表明,在0.123~30.000 μg/mL范围内、0.977~1 000.000 μg/mL范围内、0.469~30.000 μg/mL范围内6-氯苯并唑酮、精唑禾草酸、精唑禾草灵浓度与响应值线性关系良好,相关系数(r)分别为0.991 2、0.972 2、0.996 3.应用上述方法分析发现,精唑禾草灵处理后2 h在菵草体内即可检测到精唑禾草酸和6-氯苯并唑酮,药后2~96 h抗性生物型SD-04-SS体内精唑禾草灵的含量始终略高于敏感生物型SD-12,药后24~72 h抗性生物型SD-04-SS体内精唑禾草酸的含量显著低于敏感生物型SD-12,说明抗性生物型降解精唑禾草酸的速度比敏感生物型更快.     

抗性和敏感生物型菵草代谢精噁唑禾草灵的速度差异

为了测定菵草抗性生物型SD-04-SS和敏感生物型SD-12对精噁唑禾草灵代谢速度的差异,建立了精噁唑禾草灵及其主要代谢产物精噁唑禾草酸、6-氯苯并噁唑酮的高效液相色谱(HPLC)分析方法。结果表明,在0.123~30.000μg/m L范围内、0.977~1 000.000μg/m L范围内、0.469~30.000μg/m L范围内6-氯苯并噁唑酮、精噁唑禾草酸、精噁唑禾草灵浓度与响应值线性关系良好,相关系数(r)分别为0.991 2、0.972 2、0.996 3。应用上述方法分析发现,精噁唑禾草灵处理后2 h在菵草体内即可检测到精噁唑禾草酸和6-氯苯并噁唑酮,药后2~96 h抗性生物型SD-04-SS体内精噁唑禾草灵的含量始终略高于敏感生物型SD-12,药后24~72 h抗性生物型SD-04-SS体内精噁唑禾草酸的含量显著低于敏感生物型SD-12,说明抗性生物型降解精噁唑禾草酸的速度比敏感生物型更快。     

小麦田精噁唑禾草灵抗性杂草的田间监测与防控

田间监测试验表明,69g/L精噁唑禾草灵EW在小麦田疑似抗性杂草种群试验区对看麦娘、野燕麦、菵草等一年生禾本科杂草防效较差,综合株防效只有58.21%,综合鲜重防效也只有67.67%;69g/L精噁唑禾草灵EW在小麦田敏感杂草种群试验区对看麦娘、野燕麦、菵草等一年生禾本科杂草防效较好,综合株防效87.61%,综合鲜重防效88.48%。表明多年使用精噁唑禾草灵的小麦田看麦娘、野燕麦、菵草等种群均已对精噁唑禾草灵产生了抗药性。     

野燕麦对精噁唑禾草灵、炔草酯敏感性差异测定

为明确不同野燕麦种群对精噁唑禾草灵和炔草酯的敏感性水平,采用整株生物测定与种子生物测定分别检测了河南、湖北、江苏三省共11个野燕麦种群对精噁唑禾草灵和炔草酯的敏感性。结果表明,2种测定方法获得的野燕麦种群对2种除草剂的敏感性基本一致。整株生物测定结果显示,不同野燕麦种群对精噁唑禾草灵和炔草酸的敏感性存在显著差异,其中,金水闸野燕麦种群对精噁唑禾草灵和炔草酯敏感性最高,其GR50值（有效成分）分别为2.46、3.65 g/hm2,而辉县野燕麦种群对精噁唑禾草灵和炔草酯敏感性最低,GR50值（有效成分）分别为15.00、23.12 g/hm2,其余野燕麦种群对精噁唑禾草灵和炔草酯的敏感性介于金水闸种群与辉县种群之间。种子生物测定结果与整株生物测定结果趋势一致,但表现出的敏感性略高。     

稻麦连作田菵草化学防除技术研究

为延缓麦田菵草对精噁唑禾草灵抗性的形成,延长精噁唑禾草灵防除菵草的使用寿命,生产上可选择异丙隆、丁草胺、乙草胺进行土壤处理,或用甲基二磺隆取代精噁唑禾草灵进行茎叶处理,以控制麦田茼草危害.     

小麦田看麦娘对精噁唑禾草灵的抗药性水平

为了掌握小麦田看麦娘对精噁唑禾草灵的抗药性情况,采用种子生物测定和整株生物测定的方法检测江苏、上海地区看麦娘对精噁唑禾草灵的敏感性,明确其抗药性水平。结果表明,在2013年检测的23个看麦娘种群中,有12个种群对精噁唑禾草灵表现出抗药性,抗性比例达52. 17%。抗药性水平最高的是采自江苏扬州的13JYGY-4种群,抑制中剂量为1 835. 21 g a. i./hm~2,相对抗性倍数达125. 53倍。2014、2015年定点检测结果表明,抗精噁唑禾草灵看麦娘的整体抗性水平仍然较高。     

小麦田大穗看麦娘对精噁唑禾草灵的抗性

为明确小麦田大穗看麦娘对精噁唑禾草灵的抗性水平及产生抗性的机理,采用整株法测定了河南省小麦田大穗看麦娘种群对精噁唑禾草灵的抗性水平,以及细胞色素P450s抑制剂胡椒基丁醚(PBO)对精噁唑禾草灵的增效作用,并通过基因测序技术研究了其靶标ACCase基因的突变位点。结果显示:与敏感种群HN-06相比,抗性种群HN-05对精噁唑禾草灵的抗性倍数为52.2,其ACCase基因存在Ile-2041-Asn和Gly-2096-Ala位点突变;喷施PBO后,精噁唑禾草灵对大穗看麦娘的GR50值(有效成分)为5.4 g/hm^2,表现出明显的增效作用,与未喷施PBO处理的差异倍数为161.3。研究表明,抗性种群HN-05对精噁唑禾草灵已产生高水平抗性,该抗性的产生可能是由于其靶标基因突变和P450s介导的代谢增强同时导致的,即表现出了靶标抗性和非靶标抗性共存的现象。     

防治直播稻田禾本科杂草药剂的筛选及其制剂研究

筛选了五氟磺草胺和精噁唑禾草灵的最佳配比,研究了复配剂的油悬浮剂配方,并明确了该复配制剂的田间药效。结果表明,五氟磺草胺和精噁唑禾草灵的最适配比是2∶1;该油悬浮剂的最适配方是:五氟磺草胺的质量分数是4%,精噁唑禾草灵是2%,MOA-9P是15%,L-62是5%,有机膨润土是1%,气相法白炭黑是1%,油酸甲酯补足至100%;田间药效表明,6%五氟磺草胺·精噁唑禾草灵油悬浮剂18~36 g a.i./hm~2可有效防除直播稻田一年生杂草,并对水稻产量无影响。     

安徽省部分地区冬小麦田日本看麦娘Alopecurus japonicus对精噁唑禾草灵的抗性发生现状及ACCase基因突变研究

日本看麦娘Alopecurus japonicus是中国冬小麦田和油菜田主要恶性禾本科杂草之一。为了明确安徽省部分地区日本看麦娘对精齅唑禾草灵抗性发生情况及可能存在的抗性机制，本研究在安徽省天长市日本看麦娘发生严重区域冬小麦田共采集10个种群，采用温室盆栽法在整株水平上测定了不同种群对精齅唑禾草灵的抗性水平，扩增并比对了抗性和敏感种群之间靶标酶乙酰辅酶A羧化酶 (Acetyl-CoA carboxylase，ACCase) 基因部分序列的差异。结果显示，与敏感种群相比，10个抗性种群对精齅唑禾草灵均产生了高水平抗性，抗性指数在30.50~58.55之间。不同抗性种群均发生了ACCase基因突变，其中8个种群发生了第1 781位异亮氨酸 (Ile) 到亮氨酸 (Leu) 突变，2个种群发生了第2 027位色氨酸 (Trp) 到半胱氨酸 (Cys) 突变。此外，各种群均具有较高的ACCase基因突变频率 (≥80%)。研究表明，抗性日本看麦娘在安徽省部分地区发生较为严重，ACCase基因突变是导致不同日本看麦娘种群对精齅唑禾草灵产生抗性的重要原因之一。相对于第2 027位，日本看麦娘ACCase基因更倾向于在第1 781位产生突变以表现靶标抗性。     

Hymenopteran Parasitoids on Fruit-infesting Tephritidae (Diptera) in Latin America and the Southern United States: Diversity, Distribution, Taxonomic Status and their use in Fruit Fly Biological Control

We first discuss the diversity of fruit fly (Diptera: Tephritidae) parasitoids (Hymenoptera) of the Neotropics. Even though the emphasis is on Anastrepha parasitoids, we also review all the information available on parasitoids attacking flies in the genera Ceratitis, Rhagoletis, Rhagoletotrypeta, Toxotrypana and Zonosemata. We center our analysis in parasitoid guilds, parasitoid assemblage size and fly host profiles. We also discuss distribution patterns and the taxonomic status of all known Anastrepha parasitoids. We follow by providing a historical overview of biological control of pestiferous tephritids in Latin American and Florida (U.S.A.) and by analyzing the success or failure of classical and augmentative biological control programs implemented to date in these regions. We also discuss the lack of success of introductions of exotic fruit fly parasitoids in various Latin American countries. We finish by discussing the most pressing needs related to fruit fly biological control (classical, augmentative, and conservation modalities) in areas of the Neotropics where fruit fly populations severely restrict the development of commercial fruit growing. We also address the need for much more intensive research on the bioecology of native fruit fly parasitoids.     

Brief Guide for Authors

正Journal of Arid Land(JAL)is an international journal(ISSN 1674-6767;CN 65-1278/K)for the natural sciences,sponsored by the Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences and Science Press.It is published by Science Press and Springer-Verlag Berlin Heidelberg bimonthly.JAL publishes original,innovative,and integrative research from arid and semiarid regions,ad     

The parasitoid complex ofLiriomyza cicerina on chickpea (Cicer arietinum)

Liriomyza cicerina (Diptera: Agromyzidae) is an important pest on chickpea in Turkey. The objective of this study was to determine the parasitoids and rates of parasitism ofL. cicerina on chickpea (Cicer arietinum L.) during the 2005 and 2006 seasons in ?anl?urfa province, Turkey. Leaves with mines were sampled weekly and kept in the laboratory to observe and count emerging leafminer and parasitoid adults. Eight parasitoid species were collected: the braconidsOpius monilicornis Fischer andOpius tersus Foerster and the eulophidsDiaulinopsis arenaria (Erdös) andNeochrysocharis formosa (Westwood), which occurred in both the winter and summer seasons;Diglyphus crassinervis Erdös,Neochrysocharis ambitiosa Hansson,Neochrysocharis sericea (Erdös) andPediobius metallicus (Nees), which occurred only in the summer growing areas.Diaulinopsis arenaria was the predominant parasitoid with 4–7.7% parasitism rate whileN. ambitiosa andO. monilicornis were the second and third most predominant species. The results of these trials show that sinceDia. arenaria occurred throughout every season, it could potentially be used for control of the leafminerL. cicerina.     

Plant–herbivore asynchrony necessitates augmentative releases of the exotic beetle,Zygogramma bicolorata,to enhance the biological control of P arthenium hysterophorus

Systematic information on the quantitative impact of Z ygogramma bicolorata on the biology of P arthenium hysterophorus is crucial as the seeds of this weed continue to germinate from the accumulated soil seed bank throughout the year in the form of different germinating flushes, while the activity of the beetle ceases during winter as it enters diapause. Therefore, plant–herbivore interactions need to be explored to develop predictions of the overall impact of the introduced beetle on the weed. The findings revealed that defoliation by Z . bicolorata had a significant impact on the plant height, density and flower production in flushes F ₃, F ₄ and F ₅, but not in F ₁ and F ₂ that exhibited longer periodicity, profuse branching, a longer flowering period and maximum flower production and contributed mostly to the existing seed soil bank. Therefore, total depletion of the existing soil seed bank was not possible. Consequently, the effect of augmentative field releases of laboratory‐reared beetles was explored on F ₁ and F ₂ in February for three consecutive years (2011–2013). Before initiating the trial, random soil samples were taken from the plots that were assigned to the paired treatments (i.e. with the beetle and without the beetle [insecticide‐treated]) and it was found that the seed bank in those samples did not differ. The single release of Z . bicolorata adults at five per plant at the six‐leaf stage significantly reduced the soil seed bank, compared to without the biocontrol agent, irrespective of the flushes at the end of the season.     

Richtlinien der Verbände des ökologischen Landbaus zum Vorratsschutz

Zusammenfassung Verbände des ökologischen Landbaus wie z. B. Bioland, Gäa, Demeter; Naturland, Ernte für das Leben oder Bio Suisse beschränken ihre Mitglieder bei der Wahl von Vorratsschutzmaßnahmen. Vorrang besitzen Maßnahmen zur Vermeidung von Schädlingen gegenüber Bekämpfungsmaßnahmen. Fallen müssen zur Befallsüberwachung eingesetzt werden, um einen Befall durch Vorratsschädlinge frühzeitig zu erkennen. Diese Maßnahmen sollen den weitgehenden Verzicht auf chemisch-synthetische Mittel ermöglichen. In diesem Beitrag werden die Empfehlungen der Verbände mit den derzeit verfügbaren chemischen Mitteln für den Vorratsschutz abgeglichen. Erfahrung in der praktischen Umsetzung von physikalischen und biologischen Verfahren werden diskutiert und Defizite bei der Befallsüberwachung und Bekämpfung beschrieben.     

Development of protocols for detection of Colletotrichum acutatum and monitoring of strawberry anthracnose using real-time PCR

Real-time PCR (TaqMan®) assays were developed for the specific detection and discrimination of Colletotrichum spp., C. acutatum and C. gloeosporioides causing anthracnose in strawberry using the most divergent area of the internal transcribed spacers (ITS1 and ITS2) and 5·8S ribosomal RNA (rRNA) gene region. The specificity of the new assays was tested using DNA from six species of Colletotrichum and nine fungal species commonly found associated with strawberry material, and additionally by comparing the sequences with those from databases using a blast search. The sequences only showed identity with homologous sequences from the desired target organisms. The new assays were 10–100 times more sensitive than conventional PCR methods previously published for the diagnosis of strawberry anthracnose. When real-time PCR was compared with ELISA methods, PCR improved the sensitivity of the identification by obtaining positive results for samples of strawberry plant material that tested negative with ELISA. The development of C. acutatum was monitored using artificially infected strawberry crowns from two strawberry cultivars (Camarosa and Ventana) and a real-time PCR assay specific for this species between January and June 2006. The amount of C. acutatum detected using real-time PCR varied significantly by month ( P  < 0·001), but not by cultivar ( P  = 0·394). The new assays were shown to be useful tools for rapid detection and identification of these pathogens and to allow rapid and accurate assessment of the casual agents of anthracnose in strawberry.     

Effects of the saprophytic leaf mycoflora on growth and productivity of winter wheat

The effects of the saprophytic mycoflora and its interference with cereal aphids on growth and yield of winter and spring wheat was studied in field experiments in 1980, 1981 and 1982.Yields varied between 5000 and 8000 kg dry matter of kernels per ha. The effect of the saprophytic mycoflora on yield was determined in different treatments: A) no control measures against cereal aphids and saprophytic and necrotrophic fungi, B) no control of cereal aphids, control of saprophytic and necrotrophic fungi, C) control of cereal aphids and control of saprophytic and necrotrophic fungi, D) control of cereal aphids and stimulation of saprophytic mycoflora and E) control of cereal aphids, no control of saprophytic and necrotrophic fungi nor stimulation of saprophytic mycoflora.Considerable differences in top densities of saprophytic mycoflora (10 times as large in A and D as in B and C) were determined. The consequences of these differences for the growth and productivity of wheat were minor. A negative effect of saprophytic mycoflora on the yield could not be detected in 1981 and 1982, whereas a small positive significant effect was found in 1980. This stimulation may have been due to competition between necrotrophic fungal pathogens and saprophytic mycoflora. As a result of favourable weather conditions necrotrophic fungal pathogens were very numerous in 1980 and could form an important yield reducing factor. Yield levels may effect the importance of the necrotrophic and saprophytic mycoflora as yield reducing factors. Additionally, in the presence of aphid honeydew captafol was found to be relatively ineffective against saprophytic fungi.     

Relationship Between Production of the Phytotoxin Prehelminthosporol and Virulence in Isolates of the Plant Pathogenic Fungus Bipolaris sorokiniana

A gas chromatographic method was developed to quantify the phytotoxin prehelminthosporol, which is a sesquiterpene metabolite of the plant pathogen Bipolaris sorokiniana. The toxin was extracted from mycelium or culture filtrates, pre-cleaned using solid phase extraction, and analyzed by gas chromatography as a trimethylsilyl-derivative. The detection limit of the method was 5ngl^–1 (signal to noise ratio 4:1) which corresponds to ca. 15ng prehelminthosporol per mg dry weight of mycelium or 15ng prehelminthosporol per ml culture filtrate. The total amount of prehelminthosporol (mycelium plus culture filtrate) increased with cultivation time when examined in six isolates of B. sorokiniana after 6, 9, 12 and 15 days of incubation. The screening experiment of 17 isolates for prehelminthosporol production after 8 days of incubation revealed significant differences in the toxin production between the isolates. The isolates with low toxin production had lower virulence towards barley roots compared to those with higher production of the toxin. However, the virulence did not increase with prehelminthosporol level among the high producing isolates. Prehelminthosporol was also analyzed in a number of related Bipolaris and Drechslera species. In addition to B. sorokiniana, three out of six Bipolaris species (B. setariae, B. zeicola, B. victoriae) produced prehelminthosporol, which indicates that ability to produce prehelminthosporol is conserved among closely-related Bipolaris species.