北京地区小麦禾谷孢囊线虫病发生动态调查

小麦禾谷孢囊线虫病是小麦生产上的重要病害.2010-2011年对北京地区小麦禾谷孢囊线虫的发生规律进行了定期定点调查.结果表明,禾谷孢囊线虫在北京地区全年只发生1代,夏季滞育,卵孵化高峰为4月初;2龄幼虫侵染高峰为4月上旬,3龄幼虫发育高峰为4月下旬至5月初,4龄幼虫发育高峰为5月上旬,白雌虫发育高峰为5月下旬至6月上旬,10月份播种后部分2龄幼虫就可以发生侵染并且冬前发育至3龄幼虫.本研究结果可为北京地区禾谷孢囊线虫的防治提供理论依据.     

不同轮作模式下小麦禾谷孢囊线虫的发生动态和种群密度

轮作是防治小麦禾谷孢囊线虫的重要农业措施,为了明确青海省春麦区不同轮作模式对小麦禾谷孢囊线虫的控制效果,采用田间大区试验法对生产中应用的6种轮作模式进行了研究。结果表明:不同轮作模式下,小麦禾谷孢囊线虫种群密度变化差异极显著,其中小麦与马铃薯、油菜、蚕豆轮作两年或以上能有效降低小麦禾谷孢囊线虫种群密度,土壤中的孢囊量减少39.31%~84.39%,单孢虫口数量减少73.21%~95.35%,虫口密度减少83.76%~97.82%;不同作物间,小麦与马铃薯或蚕豆的轮作效果(虫口密度减少74.39%~79.37%)显著优于小麦与油菜的轮作效果(虫口密度减少67.16%)。在同一地块相同条件下,种植油菜、蚕豆、马铃薯、小麦4种作物,小麦禾谷孢囊线虫均能正常孵化,4月底土壤中的2龄幼虫(J2)量增加,5月上旬达到高峰期,5月中旬开始,土壤中的J2、孢囊量、虫口密度和单孢虫口数量均急剧下降,6月至7月份下降幅度小,趋于稳定;田间空孢囊率于5月中旬至6月中旬急剧增加,7月份趋于稳定,8月份以前,4种作物田禾谷孢囊线虫的孵化动态和种群密度变化趋势一致,8月中旬,小麦田随着新孢囊脱落到土壤中,禾谷孢囊线虫种群密度开始上升,小麦收获后土壤中的孢囊量比播种前增加28.62%,虫口密度增加41.30%;而油菜、蚕豆、马铃薯田土壤中的孢囊量比播种前减少32.27%~48.36%,虫口密度减少70.91%~81.73%,8月中旬至10月份小麦田禾谷孢囊线虫种群密度极显著高于油菜、蚕豆、马铃薯田。     

豫北及冀南地区4个小麦禾谷孢囊线虫群体的种类鉴定

禾谷孢囊线虫病(Cereal Cyst Nematode,CCN)是世界上为害小麦等禾谷类作物的重要根部线虫病害,许多国家受害严重[1].该病的病原禾谷孢囊线虫(Heterodera avenae group)是一个复合种群组,包括12个有效种和几个未命名的种,其中发生普遍、危害严重的有燕麦孢囊线虫(H.avenae)、菲利普孢囊线虫(H.filipjevi)、大麦孢囊线虫(H.hordecalis)和麦类孢囊线虫(H.latipons)[1].我国1987年在湖北省天门县首次在小麦上发现禾谷孢囊线虫病,Wang等[2]鉴定病原为燕麦孢囊线虫(H.avenae);后陆续在河南、安徽、山东等多个省份发现该病,病原均为该种线虫.2010年Li等[3]在河南许昌报道发现了菲利普孢囊线虫(H.filipjevi).     

襄阳市小麦禾谷孢囊线虫发生特点及防治技术

<正>小麦禾谷孢囊线虫病(Cerealcystnematode,CCN)是一种世界性的土传病害,一般可使小麦减产15%~25%,在实际生产中具体表现为植株矮小,叶片泛黄,分蘖减少、长势较弱,极易被判断为缺肥的症状,具有相当的隐蔽性和迷惑性。为了彻底摸清小麦禾谷孢囊线虫病在我市的分布危害情况,为进一步制定防控对策提供科学依据,我们组织全市植保系统技术人员对小麦禾谷孢囊线虫病进行了大面积区域普查和重点调查,基本摸清了该病在襄阳市的发生分布情况,并结     

江苏省小麦孢囊线虫病发生情况初步调查

2009年5月对江苏省5个地区的22个县市小麦孢囊线虫病发生情况进行了初步调查,共采集76份含根系和根际土壤的样本,经分离与鉴定表明,小麦禾谷孢囊线虫(Heterodera avenae,CCN)在徐州、连云港、宿迁和盐城等地区都有分布,检出率为35%。徐州的沛县、丰县、邳州和睢宁等4个县市的小麦孢囊线虫病检出率超过90%。其中,丰县华山镇、沛县河口镇和丰县城东的田块孢囊密度较大,每100 mL土壤的平均孢囊数分别为161、159个和112个,每个孢囊的平均含卵量分别为187、190粒和174粒。这是小麦孢囊线虫病在江苏省发生的首次报道。     

青海省小麦孢囊线虫病发生和分布特点

小麦孢囊线虫病是青海省小麦青稞产区的主要病害之一。2007-2010年,采用随机取样方法对青海省小麦孢囊线虫病的发生、分布情况进行了调查。调查结果表明,小麦孢囊线虫病主要分布在青海省西宁、海东、海北、黄南、玉树、海西州6个地区,在不同海拔、不同生态区均有分布,但不同生态区以及同一生态区不同地块间发生量差异较大。垂直分布调查结果表明,同一地块中禾谷孢囊线虫主要分布在20 cm以上的土层中。     

宜阳县小麦禾谷胞囊线虫病发生特点及防控措施

2007年5月,宜阳县植保植检站在柳泉镇武树村的麦田调查时发现,麦田出现大面积变黄、矮化,有的小麦植株提早枯死,病株穗小,籽粒不饱满,拔出病株,在根表肉眼可见针头大小白色胞囊状物,部分病株根表可见褐色胞囊,带病株和根围土经省市植保专家室内镜检等鉴定,确诊为小麦禾谷胞囊线虫病,即燕麦胞囊线虫病(Heterodera avenae Wollenweber).     

淡紫拟青霉防治小麦禾谷孢囊线虫病研究

淡紫拟青霉作为重要的植物病原线虫生防真菌在大豆孢囊线虫和蔬菜根结线虫病害防治上开始推广应用,本研究测定了该菌抑制小麦孢囊线虫病的效果,通过设置25、50、75、100kg/hm24种不同颗粒菌剂用量及5%涕灭威颗粒剂10kg//hm2计5个处理,以不施药作为空白对照。结果表明：在小麦苗期,4种不同颗粒菌剂用量和涕灭威处理后,小麦根内孢囊线虫幼虫数量和病情指数显著低于对照; 在小麦生长后期（抽穗至扬花期）,所有处理与空白对照均存在显著性差异,以100kg//hm2的防效最好,达到40.22%,这一剂量导致收获期土壤中的孢囊数量较对照减少59.82%,可见淡紫拟青霉在小麦孢囊线虫病防治上具有应用潜力。     

小麦禾谷孢囊线虫生防真菌的筛选与鉴定

禾谷孢囊线虫病是我国黄淮流域小麦主产区的重要病害,为寻找小麦禾谷孢囊线虫病的生防菌株,采用组织分离法对河南各地小麦孢囊线虫孢囊上的寄生真菌进行分离,共获得42株分离物,并进行盆栽防治效果测定.结果显示,F03,F04,F08,F1I,F13,F15,F20,F25,F26,F33和F37等11个菌株对小麦禾谷孢囊线虫具有较好的防治效果,平均防治效果均在50%以上.2008-2009年在河南许昌县的大田防治试验结果表明,F04,F08,F20,F26和F37等5个菌株表现出较好的防病作用,灌浆期平均防治效果均达到35%以上.通过形态学和rDNA-ITS PCR分子鉴定,这些菌株分别属于毛壳菌Chaetomium sp.、茄病镰刀菌Fusarium solani、草酸青霉Penicillium oxalicum,茄匍栖霉属stemphylium sonali和层出镰刀菌Fusarium proliferatum.     

鲁豫皖交界地区四个小麦禾谷孢囊线虫群体致病型鉴定

为了明确鲁豫皖交界地区小麦禾谷孢囊线虫的致病类型,利用23个国际鉴别寄主品种和1个当地小麦品种温麦19对采自山东菏泽、安徽颍上、河南商丘和淮阳的4个小麦禾谷孢囊线虫群体致病型进行了鉴定。4个群体的致病型不同于国际上已命名的16个小麦禾谷孢囊线虫致病型。13个A组鉴别寄主对山东菏泽与安徽颍上群体具有相同的抗性反应,这2个线虫群体属于同一致病型;河南商丘群体与上述2个群体的毒性相似,但大麦寄主KVL191对山东菏泽群体和安徽颍上群体表现为抗病,而对河南商丘群体表现感病;河南淮阳群体的致病谱较宽,明显不同于其它3个群体。对照小麦品种温麦19对4个小麦禾谷孢囊线虫群体均表现感病。     

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.     

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.     

Effect of botanical insecticides and bacterial toxins on the gut enzyme of the rice leaffolderCnaphalocrocis medinalis

The effect of botanical insecticides and bacterial toxins on gut enzyme activity of larvae of the rice leaffolderCnaphalocrocis medinalis (Guenée) (Insecta: Lepidoptera: Pyralidae) was investigated. Gut enzyme activities were affected by botanical insecticides and bacterial toxin individually and in combination. When fed a diet of rice leaves treated with botanical insecticides and bacterial toxins, in bioassays the activities of gut tissue enzymes — acid phosphatases (ACP), alkaline phosphatases (ALP) and adenosine triphosphatases (ATPase) — of rice leaffolder larvae were affected. When combined, the effect was more severe at a low concentration. Larvae that were chronically exposed to botanical insecticides and bacterial toxins showed a reduction in weight (59–89%) and exhibited a significant reduction in ACP, ALP and ATPase activities. The combination ofBacillus thuringiensis kurstaki and botanical insecticides caused a decrease of twofold in enzyme activity even at reduced concentration. A synergistic effect was found when botanical insecticides and bacterial toxins were combined at low doses. These effects were most pronounced in early instars. Clear dose-response relationships were established with respect to enzyme activity. In conclusion: (i) biopesticides are relatively safe and biodegradable; (ii) a synergistic effect of botanical insecticides and bacterial toxins was found; (iii) less expensive, readily available and naturally occurring biopesticides could be an alternative for organic and inorganic pesticides in controlling RLF. http://www.phytoparasitica.org posting Sept. 28, 2004.