小卷蛾斯氏线虫对沙棘木蠹蛾幼虫的室内侵染能力

沙棘木蠹蛾(Holcocerus hippophaecolus Hua,Chou,Fang et Chen)是沙棘重要蛀干性害虫之一,近年来在“三北”一些地区爆发成灾,造成大面积沙棘人工林死亡。沙棘不仅是生态建设极重要的树种,同时沙棘叶和果具很高的经济利用价值,用于开发药品和饮品,因此使用安全、有效的生物防治将成为控制沙棘木蠹蛾的重要防治措施之一。在利用线虫防治蛀干性害虫方面,     

沙棘林能源价值及平茬复壮技术研究

沙棘作为鄂尔多斯地区一种生态经济树种,但是生长到一定年龄就会出现"老化"现象,挂果量明显下降,病虫害严重,使得经济收入严重受损。通过现地平茬试验,基于平茬前沙棘的树高、冠幅、地径的调查以及平茬后的树高、冠幅、分枝数以及生物量测定数据为依据,研究发现沙棘最佳平茬树龄为8龄,留茬高度在距地表10cm为佳,茬口进行涂漆处理后萌芽生长状况较好;采用WZR-1TCⅡ型电脑自动热量计测定不同林龄沙棘植株以及各器官的热值研究结果表明:沙棘是一种高热值能源树种,去灰分热值大致在19-20KJ.g-1。沙棘各器官平均去灰分热值由大到小依次为:根﹥枝﹥叶﹥皮。最后对2010年鄂尔多斯地区营造的7118.27hm2沙棘生态经济林在生长8龄平茬后地上部分的能源价值进行估算,其能源价值相当于3.995×106t原煤的价值。     

沙棘绕实蝇入侵新疆的风险分析

沙棘(Hippophae rhamnoides L.)在新疆作为退耕还林主要树种,承担着防风固沙、保持水土的功能,并具有较好的经济价值。沙棘绕实蝇(Rhagoletis batava obseuriosa)是影响沙棘产量和质量的主要害虫。结合定性、定量指标评估沙棘绕实蝇入侵新疆的风险,得出沙棘绕实蝇危险性综合评价值R=2.22,属高度危险林业有害生物。建议在沙棘绕实蝇多发区域健全监测体系,采取具有针对性的防虫策略。     

沙棘绕实蝇成虫饲养研究

沙棘Hippophae rhamnoides是干旱半干旱地区重要的水土保持和经济树种,沙棘绕实蝇Rhagoletis batava obseuriosa是沙棘果实的主要害虫。为了解成虫生活习性和为试验提供试虫,对沙棘绕实蝇成虫的饲养方法进行了研究。以蔗糖和酵母为主配制不同配比的饲料进行饲喂,观察成虫寿命和怀卵量的差异。结果显示,以蔗糖∶酵母浸粉=3∶1的配比饲养成虫,成虫的寿命最长,雌虫平均寿命为(13.19±0.72)d,雄虫平均寿命为(14.87±0.83)d;怀卵量也最大,8日龄雌虫的平均怀卵量为(57.12±6.51)粒。对该配比饲料饲养的成虫开展了生命期望表和不同日龄怀卵量的研究,表明沙棘绕实蝇成虫可以在推荐配比的人工饲料饲喂条件下获得较长的寿命和较高的生殖力。     

沙棘种苗的主要病虫害防治及出口管理建议

沙棘为胡颓子科沙棘属,又名酸柳、酸棘、黑棘等.是一种小浆果植物,落叶灌木或亚乔木,主干可达10m,常见2m左右.常与樟子松、落叶松、云杉营造混交林,是干旱、半干旱地区绿化荒山荒坡、营造水土保持林的最佳造林模式.沙棘具有抗干旱、耐寒冷、耐贫瘠的特点,是防风、固沙和保持水土的最佳树种之一,同时义是轻工和食品、医药上业等的重要原料.所以被人们誉为"神奇植物"、"绿色瑰宝"、"整治国土的生物武器".     

黄土丘陵区四种人工灌木植被生态经济效益分析

以定西地区常见人工灌木树种柠条、沙棘、红柳、紫穗槐为研究对象,利用生态经济学原理提出其生态经济效益评价的指标体系和评价方法,通过农村社会调查和市场分析并结合影子价格法、机会成本法和影子工程法等方法．分别计算四种灌木的生态经济效益。综合效益分析表明,四种灌木树种生态效益大小顺序为沙棘＞红柳＞柠条＞紫穗槐,经济效益大小顺序为紫穗槐＞沙棘＞红柳＞柠条。从总净收益来看,四种灌木生态经济效益总和大小顺序为沙棘＞紫穗槐＞红柳＞柠条。表明沙棘是该区优良的植被恢复灌木树种,适宜在定西地区大面积推广。     

3种植物单根对土体残余抗剪强度影响的研究

课题组采用四联电动直剪仪对3种沙生植物重塑的根-土复合体及素土进行了直接剪切试验,研究其单根对提高土体残余抗剪强度的影响以及不同孔隙水承压条件下根-土复合体的残余抗剪强度变化.结果表明:浅层土压力下3种植物根-土复合体残余抗剪强度均大于素土,且柠条根系固土效果优于沙棘和白沙蒿;不同含水量梯度下,复合体存在最优含水量,该含水量条件下,根-土复合体强度达到最大值;模拟降雨条件下复合体各残余强度指标均大于非降雨条件下的指标,表现为模拟降雨条件下,3种植物复合体残余粘聚力增长率排序为柠条＞白沙蒿＞沙棘,模拟非降雨条件下排序为柠条＞沙棘＞白沙蒿.上述研究定量分析了3种植物根-土复合材料的力学特性,为水土保持树种的选择提供了理论依据,具有一定的应用价值.     

基于遗传神经网络的鄂尔多斯沙棘水土保持功能评价

为明确砒砂岩区"沙棘生态工程"建设十年以来水土流失综合治理的成效,结合人工神经网络技术和遗传算法,构建了一个拓扑结构为6-16-1的GA-BP等级评价模型。该模型以沙棘水土保持功能评价指标数据作为输入,综合评价等级值作为输出,对鄂尔多斯人工沙棘林的水土保持功能进行综合评价。评价结果表明:经过数十年的生态建设,鄂尔多斯市五个旗(区)砒砂岩区的水土流失情况得到了较好的控制,各地人工沙棘林水土保持功能综合评价等级值依次为东胜区>准格尔旗>伊金霍洛旗>达特拉旗>杭锦旗。该模型符合精度误差要求,结果客观稳定,可为日后砒砂岩区沙棘生态工程的持续开展和管理提供有效建议。     

毛乌素沙地立地类型划分与抗逆树种筛选

文中通过对毛乌素沙地立地条件和经长期自然淘汰保留下来的树种生态适应性调查分析,将毛乌素沙地划分出7种立地类型,应用综合评价法对不同立地类型上的树种进行适宜性评价,为毛乌素沙地治沙造林树种选择与配置提供科学依据。评价结果为固定沙地上筛选出最优树种7种,适宜性由大到小分别为柠条、沙柳、杨柴、花棒、樟子松、沙棘、沙地柏,较适宜树种6种,适宜性由大到小为文冠果、油松、新疆杨、紫穗槐、杜松、小叶杨;半固定沙地最优树种4种,适宜性由大到小为杨柴、花棒、沙柳、沙棘,较适宜树种3种,适宜性由大到小为柠条、沙地柏、文冠果;流动沙地最优树种为杨柴、花棒,较适宜树种为沙柳;草滩地上最优种为旱柳,较适宜树种为沙棘、乌柳、箭杆杨、沙柳;盐碱滩地上最优种为柽柳,较适宜树种为沙棘、乌柳、旱柳;硬梁地上最优树种为沙棘、油松,较适宜树种为柠条、侧柏;软梁地上最优种为柠条、沙棘,较适宜树种为榆树、油松。     

几种针阔叶树种生长水势阈和生命水势阈的研究

为了研究树木生长水势阈和生命水势阈,在干旱、半干旱地区测定研究了樟子松、油松、侧柏、白扦、沙棘、新疆杨和白刺在不同水分状况下的吸水特征、光合作用年进程。结果指出树木生长水势阈和生命水势阈具有树种差异和树木年生长发育时期的变化,年生长末期较宽,对水分胁迫适应性强的树种较宽。嫩枝生长期各树种生长水势阈(Mpa)排序:侧柏>樟子松>油松>白刺>沙棘>白扦>新疆杨;各树种生命水势阈(Mpa)排序:沙棘>油松>白刺>樟子松>白扦>侧柏>新疆杨。     

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.     

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.     

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.     

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.