番石榴产区橘小实蝇转移为害规律研究

诸多室内研究结果表明番石榴(Psidium guajava L.)是橘小实蝇[Bactrocera dorsalis (Hendel)]最嗜好的寄主。然而,自然条件下番石榴的果实成熟期均有明显的季节性,当其采收后橘小实蝇种群如何生存和繁衍尚不明确。假设番石榴果实成熟采收前后橘小实蝇会转移为害,且其转移为害规律与气象因子紧密相关。为验证该假设,本研究选择广西番石榴主产区,调查了橘小实蝇寄主种类、为害率、转移为害规律及其与气象因子的关系。结果表明,番石榴产区不同月份成熟的13种瓜果中有10种受橘小实蝇为害,番石榴的受害率最严重,最高达84.00%;橘小实蝇的转移为害规律为番石榴和杨桃(Averrhoa carambola L.)(1—2月)→番石榴、杨桃和桑葚(Morus alba L.)(3—4月)→番石榴和香水柠檬[Citrus limon (L.) Burm. f.](5月)→番石榴、香水柠檬、莲雾[Syzygium samarangense (Bl.) Merr. et Perry]、荔枝(Litchi chinensis Sonn.)和龙眼(Dimocarpus longan Lour.)裂果(6月)→番石榴、杨桃、香水柠檬和莲雾(7—9月)→番石榴、杨桃、香水柠檬、金橘[Fortunella margarita (Lour.) Swingle]和青枣(Zizyphus mauritiana Lam.)(10—12月);番石榴产区全年均可诱捕到橘小实蝇成虫,共有5个成虫发生高峰期,分别为5月下旬、7月下旬、8月下旬至9月下旬、11月上旬和12月上旬。气温和降水量分别是影响番石榴产区橘小实蝇转移为害规律的主要和次要因子。研究结果明确了番石榴产区橘小实蝇的转移为害规律及其与气象因子的相关性,为制定其种群控制策略和防治技术提供重要参考。     

应用GF-120诱杀橘小实蝇成虫效果评价

通过室内和田间引诱试验,观察不同浓度的GF-120对橘小实蝇成虫的诱杀效果以及对雌、雄两性成虫诱杀效果的差异。结果表明:在室内,GF-120原液与水为1∶4和1∶6(V/V)混合24 h时,诱杀效果最好,1∶2时效果最差;在田间,GF-120原液与水为1∶4时诱杀效果较好,1∶10时效果较差。而在本试验处理中,对橘小实蝇雌雄虫诱杀效果均无显著性差异。     

不同性诱剂对橘小实蝇的监测作用

橘小实蝇Bactrocera dorsalis是一种世界性检疫害虫,可危害250多种水果和蔬菜。通过在湖南农业大学2hm2柑橘园开展的4种不同性诱剂对橘小实蝇的监测诱集试验结果表明：橘小实蝇对湖南农业大学橘园危害并不明显,橘小实蝇（Me）诱剂对橘小实蝇的监测效果最好,可为及时发现该虫危害、监测疫情提供依据。     

杨桃橘小实蝇的防治试验

采用套袋、药剂、信息素诱集成虫等方法对杨桃果实上橘小实蝇进行防治试验，结果表明套袋防治效果最好，药剂防治效果较差，信息素诱集成虫有一定的防效，建议在激素诱集成虫的基础上进行套袋防治橘小实蝇。     

橘小实蝇生物学及防治研究

橘小实蝇Bactrocera dorsalis(Hendel)是我国南方水果生产上危害最为严重的害虫之一。对橘小实蝇在18,20,25,28,30℃下卵、幼虫、蛹的发育历期及室内条件下成虫羽化、取食、交配、产卵等生物学特性的研究,结果表明,橘小实蝇卵、幼虫、蛹的发育历期随温度的降低而延长,其发育最适温度为25～28℃。在25℃下,卵、幼虫、蛹的平均发育历期分别为1.5,16和13d;在28℃下,卵、幼虫、蛹的平均发育历期分别为1.3,14和12.5d。橘小实蝇的防治措施多使用不育处理技术,引进利用"性诱剂"捕杀柑橘小实蝇技术,达到安全、环保防治的效果。     

14种植物精油对茶尺蠖行为的影响

为获得能够应用于茶园茶尺蠖Ectropis obliqua“推—拉”策略的行为调节剂,在室内测定了茶尺蠖成虫对14种植物精油的趋性反应,及植物精油对茶尺蠖雌虫产卵行为的干扰作用,并采用叶碟法测定了植物精油对茶尺蠖幼虫的拒食作用。结果表明,罗勒、迷迭香、肉桂、茴香及天竺葵5种植物精油对茶尺蠖成虫表现出一定的驱避活性,并且迷迭香油和天竺葵油还能显著干扰雌虫的产卵活动。在3个浓度处理下,茴香、罗勒和藿香植物精油对茶尺蠖3龄幼虫表现出显著的拒食活性。随着精油处理浓度的升高,茶尺蠖幼虫的拒食率升高,生长率随之下降。试验结果证明迷迭香、罗勒、茴香及天竺葵等植物精油对茶尺蠖具有显著的行为调控功能,具备作为茶尺蠖防控剂开发的潜力,值得进一步研究。     

不同季节与气象因素对橘小实蝇日飞翔活动节律的影响

笔者于2008年夏、秋、冬3个季节,每个季节在福州乌山果园对橘小实蝇进行10d的全天观测,然后各季节分别选择3d晴朗或多云的气候条件下所得数据,结合气象资料,分析比较该虫的日飞翔活动变化情况.结果表明,橘小实蝇在不同季节的飞翔活动节律不同,在晴到多云天气里,该虫夏季的活动高峰期为上午7:00,秋季为上午9:00,冬季则为下午15:00.橘小实蝇成虫仅在白天有光照情况下进行飞翔活动,气温、相对湿度对该虫活动有显著的影响.气温在20～30℃时,橘小实蝇飞翔活动最活跃,相对湿度大于60％时其飞翔活动最活跃.降水带来的气温与相对湿度的变化对橘小实蝇飞翔活动有显著的影响.     

避雨对‘热农1号’杧果果实发育和采后耐贮性的影响

为掌握自然条件下阿里山潜蝇茧蜂[Fopius arisanus(Sonan)]对橘小实蝇[Bactrocera dorsalis(Hendel)]为害的控制效果，研究阿里潜蝇茧蜂与橘小实蝇数量之比对橘小实蝇卵的被寄生率的影响和阿里山潜蝇茧蜂对橘小实蝇的持续控制效果。结果表明：当阿里山潜蝇茧蜂与橘小实蝇数量之比达到3:1时，阿里山潜蝇茧蜂对橘小实蝇卵的寄生率达57%左右，再增加阿里山潜蝇茧蜂不会显著提高橘小实蝇卵的被寄生率；阿里山潜蝇茧蜂对橘小实蝇的有效控制时间为15 d左右。由此可见，田间应用阿里山潜蝇茧     

长沙地区实蝇监测研究

于5月至11月,采用2种诱捕器4种性诱剂对长沙地区的实蝇进行了监测,结果表明:(1)Me、Cue和蛋白诱饵性诱剂对多种实蝇具有诱集作用,其中Me性诱剂的专化性最强,诱集橘小实蝇共86头;Cue性诱剂分别诱集具条实蝇174头,瓜实蝇111头;蛋白诱饵诱集能力介于Me和Cue两种性诱剂之间,分别诱集具条实蝇17头,瓜实蝇7头,橘小实蝇12头;(2)Me和Cue性诱剂对橘小实蝇和瓜实蝇的种群发生动态、地理分布具有很好的监测效果;(3)本地区监测点未诱集到地中海实蝇。     

台风天气对橘小实蝇活动规律与种群动态的影响

2010年共有三次台风登陆福建省漳州市漳浦县。通过悬挂内置沾有稳黏瓜果实蝇诱杀液诱芯的诱捕器进行跟踪研究发现：在台风登陆的当天,由于风大雨大,诱捕到的橘小实蝇虫量比台风登陆前少;而在台风过后（或台风带来的大雨停止后）的第1天会出现一次橘小实蝇活动的高潮,平均每天每个诱捕器诱捕到的橘小实蝇虫量大增。利用这一规律进行橘小实蝇防治,将会起到事半功倍的效果。     

海南蔗区甘蔗黑穗病菌生理小种鉴定

采集海南蔗区8个县市24个乡镇的甘蔗黑穗病菌样品24份,通过甘蔗黑穗病菌鉴别寄主NCO376(免疫)、NCO310(抗小种2,感小种1)、F134(感小种2,抗小种1)、F173(高感)及主栽品种ROC22,确定海南蔗区甘蔗黑穗病菌的生理小种.接种甘蔗黑穗病菌后1a新植,2a宿根的发病情况表明:海南蔗区甘蔗黑穗病菌生理小种为小种2,或优势小种为小种2.这对了解海南蔗区甘蔗黑穗病菌生理小种的分化及分布情况,以及对今后海南蔗区甘蔗黑穗病的防控及抗黑穗病甘蔗种质的选育提供依据.     

番石榴（Psidium guajava L.）资源的ISSR分析初报

用ISSR技术分析16份番石榴资源的亲缘关系.结果表明:从11条能扩增出较清晰多态性指纹图谱的引物中,筛选出了6条引物能对所有资源均扩增出可重复的清晰指纹,共扩增出44条可重复带.其中多态性带占61.4%;扩增结果可将16份供试资源一一分开,部分资源存在同名异物现象;各资源间的相似系数在0.689～0.981之间,平均为0.841.UPGMA聚类结果将16份资源分成了3组.     

Antibacterial activity and phytochemical study of six medicinal plants used in Benin

The ethanol extracts obtained from Psidium guajava, Flacourtia flavescens Boswellia dalzielii, Ficus exasperata, Pavetta corymbosa and Hybanthus enneaspermus, six species traditionally used in Benin to treat several infectious diseases, were evaluated for their in vitro antimicrobial activity against Staphylococcus aureus, Enteroccocus feacalis, Escherichia coli and Pseudomonas aeruginosa. The minimum inhibitory concentration of extracts was determinate using the microplate dilution method. The presence of major phytoconstituents was detected qualitatively. The diphenylpicrylhydrazine radical scavenging activity was also performed. The extracts exhibited antibacterial activities against the tested bacteria. Boswellia dalzielii, Psidium guayava, Pavetta corymbosa and Flacourtia flavescens exibited the lowest minimum inhibitory concentration values (0.313-2.5 mg mL(-1)). Pseudomonas aeruginosa was the lest sensitive microorganism with MIC values higher than 10 mg mL(-1). In antioxidant assay the crude extracts of B. dalzielii and P. corymbosa appeared to be as potent as quercetol with an inhibition percentage of 83 and 75.3% at 10 microg mL(-1) which is comparable to 75.9% for quercetol at the same concentration.     

The control of isariopsis leaf spot and downy mildew in grapevine cv. Isabel with the essential oil of lemon grass and the activity of defensive enzymes in response to the essential oil

The aim of this study was to evaluate the potential of the essential oil of lemon grass (Cymbopogon citratus) for the control of isariopsis leaf spot (Pseudocercospora vitis) and downy mildew (Plasmopara viticola) in grapevine cv. Isabel, the effect of the essential oil on the productivity of the grapevines and the effect of the essential oil on the activity of the enzymes chitinase and catalase. The experiment was conducted in a commercial vineyard over two consecutive crop cycles. Each plant in the experiment was subjected to one of the following nine treatments: 0, 0.5, 1.0, 2.0 or 4.0 mL L⁻¹ essential oil, Tween^® 80%, Bordeaux mixture, Acibenzolar-S-methyl and mancozeb. An analysis of the area under the disease progress curve showed a quadratic response by both diseases to the doses of essential oil during the first and second crop cycles. The essential oil treatments also increased the number and mass of the clusters of fruit as well as the productivity and desirable chemical characteristics of the grape. The activity of chitinase increased as a result of the essential oil treatments, whereas the activity of catalase decreased. The essential oil at doses of 1.0 and 2.0 mL L⁻¹ can serve as an alternative means of controlling isariopsis leaf spot and downy mildew and can also serve to improve the fruit quality of grapes cv. Isabel in tropical regions.     

几种热带水果桔小实蝇的发生与防治

桔小实蝇[Bactroceradorsalis(Hendel)]是危害热带、亚热带水果和花芽的重要检疫性害虫之一。本研究对湛江地区芒果、杨桃、番荔枝、番石榴桔小实蝇成虫的年发生动态进行了调查。结果表明,桔小实蝇成虫在上述4种水果上拥有1￣2个发生高峰期,发生高峰期基本上与果实成熟期相吻合。杨桃果园桔小实蝇诱捕量明显高于其它3个果园桔小实蝇诱捕量。室内药效试验结果表明,40%辛硫磷乳油、48%乐斯本乳油对芒果桔小实蝇幼虫的防治效果为100%。而田间药效试验结果表明,1.8%阿维菌素、30%敌百虫和2.5%功夫对番荔枝桔小实蝇的防治效果分别为91.47%,88.74%和13.28%。甲基丁香酚 敌敌畏对桔小实蝇雄性成虫具有良好的诱杀效果,水解植物蛋白对桔小实蝇雌性成虫具有一定的诱杀作用。     

Effect of planting date on growth, development, aerial biomass partitioning and essential oil productivity of wild marigold (Tagetes minuta) in mid hills of Indian western Himalaya

A field investigation was conducted at the Institute of Himalayan Bioresource Technology, Palampur during the year 2005 to study the effect of planting dates on duration of growth and development in wild marigold (Tagetes minuta). Duration of growth phases (vegetative phase to budding phase and budding phase to 50% flowering phase), aerial biomass partitioning and essential oil production were analysed. Plantings were done in seven consequent meteorological standard weeks (MSWs) starting from the 30th MSW (30 July–5 August). Planting time coincided with distinct changes in weather parameters and consequently significant variation in the performance of the crop. The results indicated that the crop planted in the 30th and 31st MSW had the longest duration of growth and highest aerial biomass. But it partitioned more biomass towards the stem, whereas the crop planted in the 35th MSW produced significantly less biomass than the former and partitioned more towards leaf and flower and had maximum essential oil content and production. The crop planted at the 36th MSW had the minimum field duration of growth of 50 days, but the partitioning towards leaf and flower were higher than the longest field duration of growth (30th MSW). The study clearly indicated that planting dates had profound influence on growth and development of T. minuta as reflected from the significant variation on growth phase duration, aerial biomass partitioning, herb and essential oil yield.     

Comparative seasonal variation and chemical composition of essential oils from the leaves and stems of Schefflera heptaphylla using microwave-assisted and conventional hydrodistillation

Two different isolation techniques, microwave-assisted hydrodistillation (MAHD) and conventional hydrodistillation (HD), were used to extract the volatile constituents from the leaves and stems of Schefflera heptaphylla (L.) Frodin harvested during four different seasons, which were subsequently analyzed via gas chromatography with flame ionization detection and gas chromatography with mass spectrometry. MAHD is more advantageous than HD in terms of energy savings and extraction time (60 min vs. 180 min for MAHD vs. HD). Large variations in the composition among the different oils were observed. The seasonal changes in the percentages of the main constituents of the oils were irregular; this affected the quantity and composition of the oil. Oil yield was affected by the method of extraction and seasonal changes. It ranged from 0.11% to 0.27%, with the maximum amount of oil extracted from the leaves using MAHD in winter and the minimum from the stem oil extraction using HD in spring. The essential oil content varied significantly with the season. Sesquiterpene hydrocarbons constituted the major portion of the essential oils. Sesquiterpene hydrocarbons were highest in the leaf oil extraction by HD during winter (88.6%) and lowest in the stem oil extraction by HD during spring (56.3%). Microwave irradiation did not adversely affect the composition of the essential oils. MAHD, indeed, is a modern, green, and fast technology.     

Essential oil yield in peppermint/soybean strip intercropping

In the search for sustainable agricultural methods for industrial crops, peppermint $\text{(Mentha}\text{piperita)}$ was strip intercropped with soybean (Glycine max). Intercropping peppermint with soybean resulted in yield and quality increases in the essential oil, compared to sole peppermint cultivation. The yield was higher by about 50% on an equal land area basis and higher percentages of menthol and lower percentages of menthofuran and menthyl acetate improved the quality of the oil. Intercropped peppermint leaf number per node, leaf area, perimeter and leaf area index (LAI) were greater along with the internode length and thickness, when compared to monocultured plants. Total leaf peltate trichome number was higher in intercropped peppermint plants and was positively correlated with greater essential oil productivity. Leaf and stem dry weight were higher in intercropped peppermint. Total chlorophyll and carotenoid content also increased in intercropped peppermint plants, whereas no variation was found for total soluble protein. In peppermint, no significant differences were found in the CO₂ compensation point between the two cropping systems, whereas intercropped plants showed a higher stomatal conductance at low CO₂ concentration. The relationship between primary and secondary peppermint plant metabolism was also discussed.     

入侵植物胜红蓟精油对小贯小绿叶蝉的忌避和熏蒸活性研究

本文研究了入侵植物胜红蓟(Ageratum conyzoides L.)精油对小贯小绿叶蝉(Empoasca onukii Matsuda)的生物活性。分别使用植株选择着落法、Y形嗅觉仪和改良熏蒸法,检测不同浓度的胜红蓟精油对小贯小绿叶蝉的忌避和熏蒸活性。并且采用气质联用仪(GC-MS)分析了胜红蓟精油的化学成分,初步探讨了化学成分与活性的关系。研究结果表明:不同浓度的胜红蓟精油对小贯小绿叶蝉均具有忌避和熏蒸活性,浓度越高,效果越佳。精油含量为200μL·mL~(-1),忌避率达到100.00%;精油含量为100μL·mL~(-1)和50μL·mL~(-1)时,处理小贯小绿叶蝉5 min,忌避率分别为91.67%±1.67%和76.67%±1.67%;精油含量为5μL·mL~(-1)时熏蒸小贯小绿叶蝉12 h,死亡率为100%。并且胜红蓟精油中检测出24种化合物,其主要成分是β-石竹烯(61.53%)、早熟素I(11.09%)和早熟素II(7.79%)。胜红蓟精油对小贯小绿叶蝉的忌避和熏蒸活性可能与其主要成分的协同作用有关。研究结果证明,胜红蓟精油对小贯小绿叶蝉有明显的生物活性,具有开发成防治小贯小绿叶蝉植物源农药的潜力。