寄主植物对B型烟粉虱(Bemisia tabaci)和温室粉虱(Trialeurodes vaporariorum)个体发育和种群繁殖的影响

烟粉虱Bemisia tabaci(Gennadius)和温室粉虱Trialeurodes vaporariorum(Westwood)在我国北方常混合发生,为了解两种粉虱所造成的危害和自身种群的增长变化,制定科学的综合防治措施,在(27±1)℃条件下研究了两种粉虱在棉花Gossypium hirsutum L.(泗棉3号)、黄瓜Cucumis sativas L.(北京202)、茄子Solanum melongena L.(北京七叶茄)和番茄Lycopersicum esculentum Mill.(佳粉十号)上各虫态大小、存活率、发育历期、成虫寿命、平均产卵量等生物学参数。在同一种寄主植物上,温室粉虱的1,2龄若虫的体长和体宽均显著大于烟粉虱,3龄以后两种粉虱的体型则变异较大。两种粉虱从卵到成虫羽化,在棉花上的发育历期无显著差异,在黄瓜、茄子和番茄上,温室粉虱的发育历期(19.7、19.4、20.8d)显著长于烟粉虱(17.3、17.6、18.3d)。在黄瓜和番茄上,烟粉虱的平均寿命(31.2、32.1)显著长于温室粉虱的平均寿命(26、24.9d);在棉花、黄瓜和番茄上,烟粉虱的单雌产卵量(122.2、220.2、266.5粒)显著高于温室粉虱(97.1、186.6、197.1粒)。烟粉虱在棉花、黄瓜、茄子和番茄上的总存活率分别为67.9%、77.8%、67.8%和59.0%,温室粉虱依次为62.2%、67.2%、64.4%和66.1%。综合比较4种寄主植物,烟粉虱比温室粉虱具有个体发育时间短、种群繁殖速度快、生殖竞争能力强等特点。

寄主植物对B型烟粉虱(Bemisia tabaci)几种主要解毒酶活性的影响

研究测定了棉花、一品红、茄子和番茄4个B型烟粉虱(Bemisia tabaci)种群α-NA羧酸酯酶、β-NA羧酸酯酶、乙酰胆碱酯酶和谷胱甘肽S-转移酶活性。结果表明:α-NA羧酸酯酶活性与β-NA羧酸酯酶活性比值均大于1,说明B型烟粉虱水解α-NA的能力高于对β-NA的水解能力;B型烟粉虱不同寄主种群α-NA羧酸酯酶、β-NA羧酸酯酶活性个体分布频率均存在一定差异。B型烟粉虱番茄种群羧酸酯酶活性最高(93.06 mOD/(mg protein.min)),是棉花种群的1.49倍。B型烟粉虱茄子种群乙酰胆碱酯酶活性明显高于其他寄主种群,达极显著差异水平(p<0.01);茄子种群乙酰胆碱酯酶活性分布频率在>4U/mgprotein区间段的分布高达85%,与其他3个寄主种群分布明显不同。B型烟粉虱茄子种群谷胱甘肽S-转移酶活性最高,与其他3个寄主种群间的差异达极显著水平(p<0.01)。上述结果表明,B型烟粉虱主要解毒酶活性在不同的寄主植物上具有一定的生理可塑性。研究有利于揭示该害虫寄主范围广和寄主适应性强的生理生态学基础。

基于地统计学的新疆棉田烟粉虱(Bemisia tabaci(Gennadius))危害动态与时空分布

应用地统计学（GS）的原理与方法研究了外来入侵有害牛物烟粉虱（Bemisia tabaci（Gennadius））为害新疆棉田的时空动态，并与经典统计学进行对比分析。两种方法一致表明，烟粉虱成虫在空间上呈聚集分布的格局，而各时期成虫的聚集程度依据空间变异随机程度所占的比例不同而不同。经频次分布检验，以零频率法参数拟合的负二项分布来表达其空间分布型最为合适。运用Gs的分析方法，进一步得到种群分布面积变化与扩散的趋势，并依此对昆虫种群的扩散模型进行模拟。棉田烟粉虱成虫在田间7-8月份均存在一定的空间相关性，随机程度为19．22％-49．99％；空间相关距离（相关程）在一个月内从32m急速增至6372m，随后在2000-3000m的范围波动。从整个发生过程看出，烟粉虱从越冬场所顺风侵入大田后，迁飞扩散在很大程度上受风向的影响，属于典型的借助风力扩散的昆虫，其在棉田的垂直分布则与吐鲁番地区独特的暖温带大陆性干旱荒漠气候特征有关。顺风扩散时多从棉株上部叶片开始危害，而逆风扩散时从棉株中、下部叶片危害。烟粉虱在棉株上建立稳定种群后，中、下部虫口密度要略高于上部，这是烟粉虱对吐鲁番地区特殊气候的适应。

烟草野火病菌Pseudomonas syringae pv.tabaci yuexi-1信号肽预测及分析

利用Signal P 4.0、Lipo P 1.0及TMHMM v2.0对烟草野火病菌Pseudomonas syringae pv.tabaci yuexi-1菌株基因组中信号肽的数量、长度和氨基酸组成进行了预测及分类。结果确定其中432个ORFs（Open reading frame）所编码的N端有信号肽序列,占全部ORFs的8.81%。其中351条分泌型信号肽（SPI）,81条脂蛋白型信号肽（SPII）。在分泌型信号肽中,信号肽的长度为11~42个氨基酸,以长度为22个氨基酸的信号肽最多。同源性分析结果显示,具有相同信号肽序列的不同蛋白序列之间是高度保守的。该研究提供了野火病原菌致病因子的备选基因,提高该病菌致病因子的筛选效率。

烟粉虱(Bemisia tabaci)的寄主选择性

通过田间系统调查、实验室嗅觉测定、笼内和培养皿内自由扩散观察,对烟粉虱的寄主选择性进行了研究。结果表明,在田间,烟粉虱对不同的寄主植物存在明显的寄主选择性,其中对茄子、花椰菜、黄瓜等植物具有较强的嗜性,而对蕹菜、芹菜、苋菜等植物的嗜性较差;烟粉虱对同一植物的不同品种也有明显的选择性。烟粉虱对寄主植物颜色有明显的选择性,选择结果与烟粉虱对这些寄主的嗜性趋势基本一致。烟粉虱对单株寄主植物的嗅觉反应不敏感,但对植物叶片的乙醇抽提物有明显的嗅觉反应,并表现出较强的寄主选择性。在养虫笼内,烟粉虱从虫源皿向寄主植物自由扩散的过程中,在不同寄主植物和同一植物的不同品种上着落的成虫数量不同,并且在一定的时间范围内,着落在寄主叶片上的虫量还会不断的发生变化。

烟草野火病菌(Pseudomonas syringae pv.tabaci)对烟草细胞内5种防御酶系统的影响

定期测定了感病品种红花大金元接种烟草野火病菌后叶片内 5种酶活性的动态变化 ,研究结果表明 :烟草接种病菌后 ,SOD活性先上升 ,后在 8d下降 ,低于对照 ;POD活性接种后在 1d略低于对照 ,后上升较快 ,10d达到高峰 ,此后一直高于对照 ;PPO活性在接种后 1d低于对照 15 .8% ,但此后上升 ,16d达到高峰 ,18d下降低于对照 ;CAT活性变化与POD相似 ,接种 1d低于对照 ,但此后一直高于对照 ,并于 6d达到高峰 ,10d虽有所下降 ,但接着升高 ;PAL活性与CAT、POD变化相似 ,接种后 1d活性低于对照 2 8.3% ,其后上升 ,10d达到高峰 ,是对照的 2 .11倍 。

云南烟草野火病病原细菌(Pseudomonas syringae pv.tabaci)鉴定

对云南省各大烟区烟草叶片上引起褪绿晕圈的病原细菌从形态学、培养性状、生理生化反应、抗菌素反应、抗血清反应、遗传性状等方面进行了鉴定。结果表明 :该菌为烟草野火病菌 [Pseudomonassyringaepv .tabaciWolf&Foser (1917)Young ,Dye&Wilkie (1978) ]。

淡色斧瓢虫(Axinoscymnus cardilobus)对烟粉虱(Bemisia tabaci)种群的控制作用

研究了大田笼罩条件下释放淡色斧瓢虫（Axinoscymnus cardilobus）对变叶木上烟粉虱种群的控制作用。每株释放1对淡色斧瓢虫对不同密度烟粉虱种群的控制效果差异显著。瓢虫和烟粉虱以1∶20比例释放对烟粉虱的防治效果较差,以1∶80比例释放对烟粉虱的防治效果不稳定、总体上看对烟粉虱的种群几乎没有控制效果;而以1∶40的比例释放的防治效果较好、较稳定,防效为35%～95%。释放不同数量的淡色斧瓢虫对同一密度烟粉虱种群的防治效果也差异显著。7周内在1∶40、3∶40、5∶40处理区,瓢虫对烟粉虱种群的防治效果分别为35%～95%、46%～90%和50%～98%。从经济学和生态学的角度综合考虑,瓢虫和烟粉虱以3∶40比例释放比较适宜。

Diversity and Genetic Differentiation of the Whitefly Bemisia tabaci Species Complex in China Based on mtCOI and cDNA-AFLP Analysis

The whitefly Bemisia tabaci are considered as a taxonomically complex that contained some destructive pests.Two of the most prevalent cryptic species are B.tabaci Middle East-Asia Minor 1(MEAM1)and Mediterranean(MED).In an extensive field survey of the B.tabaci complex present throughout part of China from 2004 to 2007,we obtained 93 samples of B.tabaci from 22 provinces.We determined that these Chinese haplotypes included 2 invasive species(MEAM1 and MED),and 4 indigenous cryptic species(Asia II 1,Asia II 3,China 3 and Asia II 7)by sequencing mitochondrial cytochrome oxidose one gene(mtCOI).The diversity and genetic differentiation of a subset of 19 populations of B.tabaci were studied using cDNA amplified fragment length polymorphism(AFLP).Prior to 2007,MEAM1 was a dominant species in many provinces in China.By 2007,MED was dominant in 11 provinces.Both invasive and indigenous species were simultaneously found in some regions.Indigenous species of B.tabaci were found in six provinces in southern China.MED and MEAM1 have broad ranges of host plants,and indigenous species appeared to have much narrower host ranges.All Asia II 3 samples were found on cotton except one on aubergine.China 3 has more host plants than Asia II 3.Twelve samples of China 3 were collected from sweet potato,Japanese hop,squash and cotton.A total of 677 reproducible bands amplified with 5 AFLP primer combinations were obtained.The highest proportion of polymorphic bands was 98.7% and the lowest was 91.9%.Unweighted pair-group method analysis indicated that the clustering was independent of the different species.MED showed the lowest degree of similarity than the other species.The data indicate that both MEAM1and MED were rapidly established in China.

烟草野火病菌(Pseudomonas syringae pv.tabaci)诊断试剂盒的制备及应用

本研究通过筛选致病力强的烟草野火病菌株作为抗原 ,制备了烟草野火病菌特异性的抗血清 ,研制出SPA ELISA、间接 ELISA 2种诊断试剂盒 ,使检测真正作到了简便、快速、灵敏、准确。同时 ,应用这 2种诊断试剂盒对从田间及温室中采集的土壤、烟株根围、田间杂草、种子进行检测 ,明确了云南烟草野火病的初侵染源主要为种子和根围。

Bemisia tabaci Phylogenetic Groups in India and the Relative Transmission Efficacy of Tomato leaf curl Bangalore virus by an Indigenous and an Exotic Population

Bemisia tabaci adults from various host-plant species were collected from 31 regions across India.266 B.tabaci samples were first screened by RAPD-PCR to examine molecular variability and to select individuals with different fingerprints.Host-plant and region of collection were then used to select 25 individuals for PCR amplification and sequencing of their partial mitochondrial cytochrome oxidase subunit one(mtCOI)genes.Pairwise comparisons with mtCOI consensus sequences showed that the majority of these samples had <3.5% sequence divergence from groups currently termed Asia I,Asia II-5,Asia II-7,and Asia II-8.The biotype-B B.tabaci from India clustered into the Middle East-Asia Minor 1 group.A new group of B.tabaci from Coimbatore,collected from pumpkin,was related most closely to the Asia I group(6.2% sequence divergence from the consensus Asia I sequence).To increase our understanding of the epidemiology of tomato leaf curl disease(ToLCD)and the key B.tabaci genetic groups involved in virus spread,the indigenous Asia I and the exotic biotype-B population from South India were used to carry out transmission experiments using Tomato leaf curl Bangalore virus(ToLCBV).The acquisition access periods(AAP),inoculation access periods(IAP),latent periods(LP),and ToLCBV transmission efficiencies of the two populations were compared and the biotype-B had the more efficient transmission characteristics.These results are discussed in relation to recent changes in the epidemiology of tomato leaf curl disease in South India.

蜡蚧轮枝菌Lecanicillium lecanii次生代谢产物对烟粉虱Bemisia tabaci的忌避作用模型

蜡蚧轮枝菌Lecanicillium lecanii(Z imm.)viegas V l6063菌株在2种不同培养基发酵培养后,经萃取、干燥浓缩得到4种不同的毒素粗提物(次生代谢产物),用均匀设计法设计实验方案研究了4种不同毒素粗提物对4种不同寄主植物上烟粉虱Bem isia tabaci(Gennad ius)成虫的忌避作用,并构建了模型,分析结果表明,忌避作用与毒素粗提物浓度显著相关,忌避率随毒素粗提物浓度增大而增大,1 g/L浓度的毒素粗提物忌避率与烟粉虱的寄主植物相关不显著,毒素的忌避作用与培养基相关不显著,从菌株发酵的菌丝体和发酵液中提取的毒素粗提物的忌避率差异不显著。

Sequence Analysis of mtDNA CO/Gene and Molecular Phylogeny of Different Geographical Populations of Bemisia tabaci (Gennadius)

Bemisia tabaci(Gennadius) is a serious pest in many cropping systems worldwide and occurs in different biotypes. ThemtDNA COI gene of the 12 Bemisia tabaci (Gennadius) populations from different regions and countries were analyzed.Based on mtDNA COI sequences, their biotypes were characterized and phylogenetic relationships among thesepopulations were established with the method of UPGMA. The results indicated the genetic similarity between thosepopulations from Beijing, Zhengzhou, Zaozhuang, Nanjing, Shanghai, Haikou, and the B-biotype populations fromCalifornia, Texas, Arizona reached 99.8-100%, which meant the nation-wide infested populations of B.tabaci in China inrecent years were B-biotypes. Another population collected from Kunming of Yunnan Province showed very high similaritywith Q-biotype B.tabaci from Spain and Morocco, which meant the Kunming population was Q-biotype. This is the firstreport on the invasion of Q-biotype into China.

Transmission characteristics of Tomato chlorosis virus (ToCV) by Bemisia tabaci MED and its effects on host preference of vector whitefly

The epidemiology of Tomato chlorosis virus(ToCV)in China is closely associated with its vector whitefly,Bemisia tabaci(Gennadius)MED.However,the transmission characteristics of ToCV by B.tabaci MED remain poorly understood.In this study,we analyzed:1)the horizontal and vertical transmission of ToCV by B.tabaci MED whiteflies;2)the acquisition of ToCV by male and female B.tabaci MED whiteflies after different feeding durations;3)the transmission efficacy of viruliferous male and female B.tabaci MED whiteflies after different inoculation access periods(IAPs);4)the retention of ToCV by viruliferous male and female B.tabaci MED whiteflies after a 48 h acquisition access period(AAP);and 5)the effects of ToCV on host choice of healthy or ToCV-infected tomato plant of viruliferous and non-viruliferous B.tabaci MED at different time points.Our results showed that:1)viruliferous males could not transfer ToCV to non-viruliferous females,and vice versa,viruliferous females could not pass on ToCV to non-viruliferous males.ToCV could not be detected in the F1 generation adults;2)ToCV could be detected within 4.0%of females or males after a 20 min AAP;3)ToCV could be detected in 33.3%of tomato plants inoculated by 10 viruliferous males or females with IAPs of 20 or 30 min;4)the maximum retention time in females was 7 and 5 days in males;and 5)non-viruliferous B.tabaci MED did not show a preference for ToCV-infected tomato plants or healthy tomato plants.However,viruliferous B.tabaci MED whiteflies did prefer to settle on healthy tomato plants over ToCV-infected tomato plants.These findings will be helpful to better understand the epidemiology of the recently emerged plant virus,ToCV,in tomato fields in China.

cDNA Cloning of Heat Shock Protein Genes and Their Expression in an Indigenous Cryptic Species of the Whitefly Bemisia tabaci Complex from China

Thermal adaptation plays a fundamental role in shaping the distribution and abundance of insects,and heat shock proteins(Hsps)play important roles in the temperature adaptation of various organisms.To better understand the temperature tolerance of the indigenous ZHJ2-biotype of whitefly Bemisia tabaci species complex,we obtained complete cDNA sequences for hsp90,hsp70,and hsp20 and analyzed their expression profiles under different high temperature treatments by real-time quantitative polymerase chain reaction.The high temperature tolerance of B.tabaci ZHJ2-biotype was determined by survival rate after exposure to different high temperatures for 1 h.The results showed that after 41°C heat-shock treatment for 1 h,the survival rates of ZHJ2 adults declined significantly and the estimated temperature required to cause 50% mortality(LT50)is 42.85°C for 1 h.Temperatures for onset(Ton)or maximal(Tmax)induction of hsps expression in B.tabaci ZHJ2-biotype were 35 and 39°C(or 41°C).Compared with previous studies,indigenous ZHJ2-biotype exhibits lower heat temperature stress tolerance and Ton(or Tmax)than the invasive B-biotype.

p38 MAPK is a Component of the Signal Transduction Pathway Triggering Cold Stress Response in the MED Cryptic Species of Bemisia tabaci

Cold stress responses help insects to survive under low temperatures that would be lethal otherwise.This phenomenon might contribute to the invasion of some Bemisia tabaci cryptic species from subtropical areas to temperate regions.However,the molecular mechanisms regulating cold stress responses in whitefly are yet unclear.Mitogen-activated protein kinases(MAPKs)which including p38,ERK,and JNK,are well known for their roles in regulating metabolic responses to cold stress in many insects.In this study,we explored the possible roles of the MAPKs in response to low temperature stresses in the Mediterranean cryptic species(the Q-biotype)of the B.tabaci species complex.First,we cloned the p38 and ERK genes from the whitefly cDNA library.Next,we analyzed the activation of MAPKs during cold stress in the Mediterranean cryptic species by immuno-blotting.After cold stress,the level of phospho-p38 increased but no significant change was observed in the phosphorylation of ERK and JNK,thus suggesting that the p38 might be responsible for the defense response to low temperature stress.Furthermore,we demonstrated that:i)3 min chilling at 0°C was sufficient for the activation of p38 MAPK pathway in this whitefly;and ii)the amount of phosphorylated p38 increased significantly in the first 20 min of chilling,reversed by 60 min,and then returned to the original level by 120 min.Taken together,our results suggest that the p38 pathway is important during response to low temperature stress in the Mediterranean cryptic species of the B.tabaci species complex.

First report of field resistance to cyantraniliprole, a new anthranilic diamide insecticide, on Bemisia tabaciMED in China

The Bemisia tabaci(Gennadius)cryptic species complex comprises important insect pests that cause devastating damage to agricultural crops worldwide.In China,the B.tabaci Mediterranean(MED)(or biotype Q)species is threatening agricultural production all over the country as resistance to commonly used insecticides has increased.This situation highlights the need for alternative pest control measures.Cyantraniliprole,a novel anthranilic diamide insecticide,has been widely employed to control Hemipteran pests.To monitor the levels of resistance to cyantraniliprole in B.tabaci field populations in China,bioassays were conducted for 18 field samples from nine provinces over two years.Compared with median lethal concentration(LC_(50))for the MED susceptible strain,all field samples had significantly higher resistance to cyantraniliprole.Furthermore,resistance factors(RFs)increased significantly in samples from Shanxi(from 5.62 in 2015 to 25.81 in 2016),Hunan(3.30 in 2015 to 20.97 in 2016)and Hubei(from 9.81 in 2015 to 23.91 in 2016)provinces.This study indicates a considerable decrease in the efficacy of cyantraniliprole against B.tabaci and establishes a baseline of susceptibility that could serve as a reference for future monitoring and management of B.tabaci resistance to cyantraniliprole.

Characterization of field-evolved resistance to cyantraniliprole in Bemisia tabaci MED from China

Cyantraniliprole is a novel anthranilic diamide insecticide with significant efficacy against Bemisia tabaci,an important pest insect worldwide.In this study,we conducted reversion and selection work and genetic analysis,and determined cross-resistance spectrum and synergism of cyantraniliprole resistance based on the reported population,SX population,of B.tabaci collected from Shanxi Province,China.Compared with a susceptible strain(MED-S),SX population,the field-evolved cyantraniliprole-resistant population exhibited 26.4-fold higher resistance to cyantraniliprole.In SX,a sharp decline of cyantraniliprole resistance was shown in the absence of selection.Another tested strain,SX-R,was established from SX population after successive selection with cyantraniliprole and recently developed 138.4-fold high resistance to cyantraniliprole.SX-R had no cross-resistance to abamectin,imidacloprid,thiamethoxam,sulfoxaflor,or bifenthrin.Genetic analysis illustrated that cyantraniliprole resistance in SX-R was autosomally inherited and incompletely dominant.Additionally,piperonyl butoxide(PBO)significantly inhibited cyantraniliprole resistance in the SX-R strain.In conclusion,the selection of SX with cyantraniliprole led to high resistance to cyantraniliprole which is incompletely dominant and no cross-resistance to several common types of insecticides.Enhanced oxidative metabolism is possibly involved in the resistance of SX-R,yet target-site resistance could not be excluded.

Bemisia tabaci Biotype Dynamics and Resistance to Insecticides in Israel During the Years 2008-2010

The sweetpotato whitefly Bemisia tabaci(Hemiptera:Aleyrodidae)is an extremely polyphagous insect pest that causes significant crop losses in Israel and worldwide.B.tabaci is a species complex of which the B and Q biotypes are the most widespread and damaging worldwide.The change in biotype composition and resistance to insecticide in Israel was monitored during the years 2008-2010 to identify patterns in population dynamics that can be correlated with resistance outbreaks.The results show that B biotype populations dominate crops grown in open fields,while Q biotype populations gradually dominate crops grown in protected conditions such as greenhouses and nethouses,where resistance outbreaks usually develop after several insecticide applications.While in previous years,Q biotype populations were widely detected in many regions in Israel,significant domination of the B biotype across populations collected was observed during the year 2010,indicating the instability of the B.tabaci population from one year to another.Reasons for the changing dynamics and the shift in the relative abundance of B.tabaci biotype,and their resistance status,are discussed.

Next Generation Transcriptome Sequencing and Quantitative Real-Time PCR Technologies for Characterisation of the Bemisia tabaci Asia 1 mtCOI Phylogenetic Clade

A programme of functional genomics research is underway at the University of Greenwich,UK,to develop and apply genomics technologies to characterise an economically-important but under-researched Bemisia tabaci(Hemiptera:Aleyrodidae),the Asia 1 mtCOI phylogenetic group.A comparison of this putative species from India with other important B.tabaci populations and insect species may provide targets for the development of more effective whitefly control strategies.As a first step,next-generation sequencing(NGS)has been used to survey the transcriptome of adult female whitefly,with high quality RNA preparations being used to generate cDNA libraries for NGS using the Roche 454 Titanium DNA sequencing platform.Contig assemblies constructed from the resultant sequences(301 094 reads)using the software program CLC Genomics Workbench generated 3 821 core contigs.Comparison of a selection of these contigs with related sequences from other B.tabaci genetic groups has revealed good alignment for some genes(e.g.,HSP90)but misassemblies in other datasets(e.g.,the vitellogenin gene family),highlighting the need for manual curation as well as collaborative international efforts to obtain accurate assemblies from the existing next generation sequence datasets.Nevertheless,data emerging from the NGS has facilitated the development of accurate and reliable methods for analysing gene expression based on quantitative real-time RT-PCR,illustrating the power of this approach to enable rapid expression analyses in an organism for which a complete genome sequence is currently lacking.