B型烟粉虱取食诱导烟草对烟蚜防御反应的时间效应

为了明确B型烟粉虱Bemisia tabaci取食诱导烟草对烟蚜Myzus persicae的防御反应和时间效应,探讨外来入侵害虫B型烟粉虱取食诱导的烟草防御反应在其与桃蚜种间竞争中的作用,本研究采用小叶笼法和生化分析法,分别研究了B型烟粉虱取食诱导烟草对烟蚜生长发育的影响和烟草主要营养指标的变化。结果表明：B型烟粉虱取食诱导的烟草可对烟蚜产生明显的防御反应,对烟蚜的存活和生长发育有显著的抑制作用和时间效应。在烟粉虱若虫危害烟草至第5天,烟草系统白脉叶片上烟蚜的死亡率较对照叶片上烟蚜的死亡率升高36.13%;至第10天死亡率升高72.78%,且平均相对生长率较对照显著降低;至第15天死亡率升高仍达58.89%。在烟粉虱若虫危害至第10天时,将处理植株上的烟粉虱的若虫虫体去除,然后在烟草系统白脉叶片上接烟蚜1龄若蚜,在去虫后15 d内,烟草系统白脉叶片对烟蚜死亡率及相对生长率的影响较不去虫的对照间均有明显差异（P<0.05）。但至去虫后第20天,对烟蚜的不利影响即消失。研究表明B型烟粉虱取食诱导的烟草系统白脉叶片对烟蚜的抗性能持续表达15 d左右。烟粉虱危害后的局部带虫叶片与对照相比,对烟蚜的生长发育没有明显的不利影响。B型烟粉虱危害的烟草,其可溶性糖和可溶性蛋白的含量降低,这与烟蚜的死亡率表现出显著的负相关性。     

烟粉虱及海氏桨角蚜小蜂对中国番茄黄化曲叶病毒感染烟草的嗅觉反应

双生病毒可通过调控寄主植物促进媒介昆虫烟粉虱种群增长,然而病毒侵染植物后是否通过调控植物挥发物来影响烟粉虱及其天敌的嗅觉反应还未见报道。【目的】本文旨在研究烟草植株感染中国番茄黄化曲叶病毒(Tomato yellow leaf curl China virus,TYLCCNV)后对烟粉虱Bemisia tabaci(Gennadius)及其重要寄生性天敌海氏桨角蚜小蜂Eretmocerus hayati(Zolnerowich and Rose)嗅觉反应行为的影响。【方法】利用Y形嗅觉仪方法,我们测试了烟粉虱及海氏桨角蚜小蜂对带毒植株、健康植株及烟粉虱危害植株的选择偏好性。【结果】烟粉虱及海氏桨角蚜小蜂选择携带TYLCCNV病毒的烟草显著多于健康烟草植株,但烟草被病毒与烟粉虱共同侵染时,烟粉虱对带毒烟草的选择仍显著多于无毒植株,而寄生蜂虽然仍较多选择带毒植株,但无显著差异。【结论】这些结果表明烟粉虱及海氏桨角蚜小蜂偏好选择携带TYLCCNV病毒的烟草,但这种偏好作用在烟粉虱取食共同危害时有一定程度的减弱。本研究首次报道了双生病毒侵染植物可增加烟粉虱及其天敌对植物的选择作用,并就其功能及机制进行了讨论。     

Q型烟粉虱对不同烟草品种的选择性

【目的】明确Q型烟粉虱对不同烟草品种的选择性及与叶背茸毛密度的相关性,为烟草抗虫品种的选育应用及对该虫的综合治理提供理论依据。【方法】在控制条件下,进行选择性试验、非选择性试验,观察发育历期和叶背茸毛数量。【结果】烟草品种对Q型烟粉虱成虫选择性、产卵趋性及卵-成虫的发育历期影响显著,叶背茸毛密度与成虫趋性及产卵量之间具有显著相关性。在供试的8个烟草品种中,‘CF225’、‘CF226’叶背茸毛密度高,Q型烟粉虱对它们的选择性强,表示这两个品种的烟草的抗虫性弱;‘云烟117’、‘K328(C8)’叶背茸毛密度低,Q型烟粉虱对它们的选择性弱,表示这两个品种的烟草的抗虫性强。【结论】选育少毛的烟草品种,可以提高烟草对Q型烟粉虱的抗性,本结果对烟草抗虫品种的选育有一定的参考价值。     

辣椒品种对烟粉虱的抗生性研究

【目的】通过对不同品种辣椒叶片内容物和烟粉虱Bemisia tabaci(Gennadius)种群数量的相关关系研究,探讨辣椒品种对烟粉虱的抗生性机制。【方法】在不同品种辣椒上饲养烟粉虱,研究烟粉虱的种群趋势指数,同时测定不同辣椒品种叶片中可溶性糖、可溶性蛋白、游离脯氨酸、酚类化合物和黄酮类化合物含量,分析烟粉虱种群数量与辣椒内容物的相关关系。【结果】不同品种辣椒上烟粉虱的种群趋势指数存在显著差异;抗虫辣椒品种叶片中可溶性糖、酚类化合物和黄酮类化合物含量显著高于感虫品种,可溶性蛋白、游离脯氨酸含量显著低于感虫品种。烟粉虱种群趋势指数与可溶性糖、酚类化合物和黄酮类化合物含量呈显著负相关,与可溶性蛋白、游离脯氨酸含量呈显著的正相关,其中可溶性糖含量对烟粉虱种群趋势指数影响最大。对可溶性糖(X_1)、可溶性蛋白(X_2)、游离脯氨酸(X_3)、酚类化合物(X_4)、黄酮类化合物(X_5)的含量5个因素与烟粉虱种群趋势指数(Y)进行多元回归分析,其回归方程为:Y=47.801-1.754X_1+1.206X_2+1.108X_3-0.437X_4-0.649X_5(R~2=0.688)。【结论】抗性辣椒品种对烟粉虱具有明显的抗生性。     

供氮水平对番茄苗期Q型烟粉虱成虫种群动态的影响

烟粉虱(Bemisia tabaci)是重要的农业害虫。在栽培管理中,为了减少化学农药的施用,对该害虫采取生态防控措施日益得到重视。以Q型烟粉虱为研究对象,根据温室大棚内9次烟粉虱成虫种群数量调查和番茄苗期5项农艺指标测量,结合主成分分析、线性逐步回归分析及Pearson相关性分析,从"氮素-番茄-Q型烟粉虱"互作角度开展生态防控措施研究,旨在探明番茄苗期的烟粉虱成虫种群发生数量与氮素水平关系。结果表明:3个氮水平(高氮1134 mg·L^-1,标准氮945 mg·L^-1,低氮756 mg·L^-1)下的5个番茄指标(株高、茎粗、叶面积、叶绿素相对含量、叶片全氮含量)最大值基本呈现高氮>标准氮>低氮的规律;调查的9次烟粉虱虫口数量在最大峰值时的高低排序为高氮>标准氮>低氮。主成分分析表明,3种氮素水平下叶绿素相对含量是影响烟粉虱成虫虫口数量的主要因子。线性回归与相关性分析表明,3种氮素水平下的叶片全氮含量、叶绿素相对含量与虫口种群数量相关性较高。氮营养是影响植物和烟粉虱的关键因素之一,高氮水平下番茄长势较好,Q型烟粉虱虫口数量居多;作物叶片全氮含量和叶绿素相对含量可作为检测Q型烟粉虱种群发生消长的生态防控指标。     

B型烟粉虱为害烟草后对斜纹夜蛾成虫产卵和幼虫取食行为的影响

为明确外来入侵害虫B型烟粉虱取食诱导的烟草防御反应对斜纹夜蛾的影响,探讨其与斜纹夜蛾的种间竞争机制,在室内条件下研究了B型烟粉虱取食后的烟草对斜纹夜蛾成虫产卵选择、幼虫取食选择、拒食作用和其他取食行为指标的影响.结果表明:斜纹夜蛾成虫在B型烟粉虱为害后的植株上的落卵量较对照植株降低了40.9%.B型烟粉虱为害的虫体叶对斜纹夜蛾初孵化幼虫具有明显的驱避作用,而中间叶和系统白脉叶有一定的吸引作用,心叶不影响幼虫对寄主的选择性.B型烟粉虱为害叶片对斜纹夜蛾幼虫具有显著的拒食作用,虫体叶拒食作用明显大于系统白脉叶片.与对照相比,B型烟粉虱为害的虫体叶和系统白脉叶降低了斜纹夜蛾幼虫单位时间取食次数或取食比例,虫体叶还显著延长了幼虫开始取食时间,总取食面积显著减少.表明B型烟粉虱为害烟草对斜纹夜蛾成虫产卵和幼虫取食行为均产生不利影响.研究结果对了解烟田害虫种群变动规律和指导害虫治理具有较大意义.     

甘蓝与黄瓜寄主上B型烟粉虱和温室白粉虱蜜露糖分、氨基酸和挥发物组分的比较分析

粉虱蜜露是粉虱寄生性天敌搜索寄主的主要利它素源。应用离子色谱分别对甘蓝与黄瓜上B型烟粉虱(Bemisia tabaci B-biotype)蜜露以及黄瓜上温室白粉虱Trialeurodes vaporariorum蜜露的接触性利它素糖和氨基酸组分和含量进行了比较研究。结果表明：2种粉虱在不同寄主植物上的蜜露均富含糖和氨基酸,其中糖含量占绝对优势,甘蓝上B型烟粉虱蜜露、黄瓜上B型烟粉虱蜜露和黄瓜上温室白粉虱蜜露中的糖含量分别是相应氨基酸含量的42.5、2.6和5.4倍,其中糖类物质中又以寡糖含量占绝对优势,分别占89.3%、81.7%和88.2%。不同寄主植物和粉虱种类显著影响蜜露中糖和氨基酸的组成和含量。其中,甘蓝上B型烟粉虱蜜露中的寡糖以二糖占优势,占97.3%;二糖中又以蔗糖异构糖和松二糖占优势,分别占52.7%和35.4%。黄瓜上B型烟粉虱蜜露和温室白粉虱蜜露寡糖中以三糖和四糖占优势,分别占73.1%和85.4%;优势糖水苏（四）糖和松三糖分别占40.3%和 26.2%及49.9%和27.0%。甘蓝上B型烟粉虱蜜露中氨基酸以丙氨酸占优势,含量为66.5%;而黄瓜上B型烟粉虱及温室白粉虱蜜露中氨基酸以甘氨酸含量最高,分别占氨基酸总量的38.2%和51.7%。应用GC-MS对甘蓝上B型烟粉虱蜜露和黄瓜上温室白粉虱蜜露挥发物组分的鉴定结果显示,两种粉虱蜜露中共同含有的主要挥发物为邻苯二甲酸二（2-乙基）己酯。     

烟粉虱体内营养物质对寄主植物多代诱导的响应

比较同一遗传背景的B型烟粉虱Bemisia tabaci Gennadius种群成虫在甘蓝、黄瓜和一品红上的适合度差异,测定3种寄主植物主要营养差异,并分析饲养不同时间后成虫体内的蛋白质、氨基酸和游离脂肪酸含量的多代变化规律。结果发现,B型烟粉虱成虫在黄瓜上的相对适合度最高,其次是甘蓝,在一品红上适合度最低,这可能与黄瓜叶片的总氮含量高和总糖含量低有关。饲养时间对烟粉虱体内主要营养物质含量没有显著影响,但寄主植物对烟粉虱成虫体内主要营养物质含量影响显著。在黄瓜上饲养烟粉虱成虫体内蛋白质含量都显著高于一品红和甘蓝上烟粉虱成虫的蛋白质含量,在黄瓜上饲养烟粉虱成虫总氨基酸含量都显著低于一品红和甘蓝上烟粉虱成虫的总氨基酸含量。相反,在3种寄主上饲养烟粉虱成虫游离脂肪酸含量都无显著差异。可见,寄主植物对B型烟粉虱体内主要营养物质组成影响显著,但饲养时间对B型烟粉虱体内主要营养物质组成影响较小。     

B型烟粉虱在6个烟草品种上的取食行为

【背景】不同烟草品种会影响B型烟粉虱的取食选择性,但具体的机制尚不明确。刺吸电波图（EPG）技术是研究刺吸式昆虫对寄主植物取食选择性的重要手段,通过烟粉虱取食产生的电信号,可以分析其对不同烟草品种的取食差异。【方法】应用EPG技术对B型烟粉虱雌成虫在6个烟草品种（翠碧1号、K326、闽烟7号、云烟85、云烟87、红花大金元）上的取食行为进行比较研究。【结果】6个烟草品种上有效记录的雌成虫数均为18头,在翠碧1号、K326、闽烟7号、云烟87、云烟85和红花大金元叶片上能够到达韧皮部的个体数分别为15、15、12、13、15和15头,能够持续吸食的个体数分别为13、14、8、12、14和15头。烟粉虱雌成虫在6个烟草品种上的非刺探（np）波所占的比例差异显著,在红花大金元上所占的比例最小,显著低于其他5个品种。雌成虫在红花大金元和K326上E1波的总持续时间显著短于闽烟7号和云烟87。雌成虫在红花大金元上E2波的总持续时间显著长于其他5个品种,而在闽烟7号、云烟87和云烟85上显著短于其他3个品种。【结论与意义】在6个烟草品种中,B型烟粉虱雌成虫最喜食红花大金元,最不喜食闽烟7号和云烟87。因此,在福建省B型烟粉虱的发生区,选择烟草品种时可根据实际情况减少红花大金元的种植,增多闽烟7号和云烟87等抗B型烟粉虱品种的种植。     

烟草品种和温度对B型烟粉虱和温室白粉虱生物学参数的影响

在室内20℃、26℃和30℃三个设定温度条件下,研究了CF-965、NC-89和NC-82三个烟草品种对B型烟粉虱和温室白粉虱生长发育和繁殖的影响.结果表明:26℃时两种粉虱在CF-965、NC-89和NC-82三个烟草品种上的发育历期没有明显差异,但温室白粉虱卵期和若虫期的发育历期较烟粉虱依次分别延长了1.32d、2.81d和 2.04d.在CF-965上,B型烟粉虱卵期和若虫期的总存活率和平均单雌产卵量分别为54.19%和55.17粒,温室白粉虱仅分别为31.99%和39.17粒;在NC-89上,B型烟粉虱卵期和若虫期的总存活率和平均单雌产卵量分别为23.47%和37.50粒,温室白粉虱仅分别为15.75%和17.25粒;两种粉虱在NC-82上卵期和若虫期的总存活率和平均单雌产卵量差异不大,表明B型烟粉虱对CF-965和NC-89的适应能力较温室白粉虱强.两种粉虱在20℃时的发育历期最长,32℃时最短,26℃时居中.20°C时烟粉虱卵期和若虫期的存活率20.96%为最低,26℃和32℃时分别达54.19% 和53.29%;而温室白粉虱在32℃条件下存活率11.66%为最低,20℃和 26℃时分别达31 34% 和31.99%.温室白粉虱在20℃时产卵量大于烟粉虱, 在26℃时的产卵量小于烟粉虱,30℃时则不能产卵,但烟粉虱成虫30℃时的产卵量仍可达21.06粒.由此说明烟粉虱在较高温度条件下的适应能力显著强于温室白粉虱.山东烟区烟草生长中期的田间平均温度多在22～30℃,适合B型烟粉虱的发生,应引起高度重视.     

烟粉虱和温室粉虱在甘蓝上的刺探取食行为比较

利用刺吸电波图技术研究B型、ZHJ_1型烟粉虱Bemisia tabaci(Gennadius)和温室粉虱Trialeurodes vaporariorum(Westwood)在甘蓝上的取食行为,将3种粉虱的电波图进行比较,其中,B型和ZHJ_1型烟粉虱记录到np,C,pd,E1,E2,F和G波7种波形,温室粉虱只记录到刺探波形,少有取食波形。B型的20个记录中只有1个没有持续吸食波形;ZHJ_1型的25个记录中有10个记录没有持续吸食波形;温室粉虱没有持续吸食记录。甘蓝叶片韧皮部的结构或汁液的化学成分与温室粉虱的抗性密切相关。     

Role of polyisoprenoids in tobacco resistance against biotic stresses

Infection with avirulent pathogens, tobacco mosaic virus (TMV) or Pseudomonas syringae pv. tabaci induced accumulation of polyisoprenoid alcohols, solanesol and a family of polyprenols [from polyprenol composed of 14 isoprene units (Pren-14) to -18, with Pren-16 dominating] in the leaves of resistant tobacco plants Nicotiana tabacum cv. Samsun NN. Upon TMV infection, solanesol content was increased seven- and eight-fold in the inoculated and upper leaves, respectively, while polyprenol content was increased 2.5- and 2-fold in the inoculated and upper leaves, respectively, on the seventh day post-infection. Accumulation of polyisoprenoid alcohols was also stimulated by exogenously applied hydrogen peroxide but not by exogenous salicylic acid (SA). On the contrary, neither inoculation of the leaves of susceptible tobacco plants nor wounding of tobacco leaves caused an increase in polyisoprenoid content. Taken together, these results indicate that polyisoprenoid alcohols might be involved in plant resistance against pathogens. A putative role of accumulated polyisoprenoids in plant response to pathogen attack is discussed. Similarly, the content of plastoquinone (PQ) was increased two-fold in TMV-inoculated and upper leaves of resistant plants. Accumulation of PQ was also stimulated by hydrogen peroxide, bacteria ( P.  syringae ) and SA. The role of PQ in antioxidant defense in cellular membranous compartments is discussed in the context of the enzymatic antioxidant machinery activated in tobacco leaves subjected to viral infection. Elevated activity of several antioxidant enzymes (ascorbate peroxidase, guaiacol peroxidase, glutathione reductase and superoxide dismutase, especially the CuZn superoxide dismutase isoform) and high, but transient elevation of catalase was found in inoculated leaves of resistant tobacco plants but not in susceptible plants.     

Expression of the Tomato Pto Gene in Tobacco Enhances Resistance to Pseudomonas syringae pv tabaci Expressing avrPto

The Pto gene encodes a serine-threonine kinase that confers resistance in tomato to Pseudomonas syringae pv tomato strains expressing the avirulence gene avrPto. We examined the ability of Pto to function in tobacco, a species that is sexually incompatible with tomato. Evidence that a heterologous Pto-like signal transduction pathway is present in tobacco was suggested by the fact that tobacco line Wisconsin-38 exhibits a hypersensitive response after infection with P. syringae pv tabaci expressing avrPto. We introduced a Pto transgene into cultivar Wisconsin-38 and assessed the ability of transformed plants to further inhibit growth of the P. s. tabaci strain expressing avrPto. The Pto-transformed tobacco plants exhibited a significant increase in resistance to the avirulent P. s. tabaci strain compared with wild-type tobacco as indicated by (1) more rapid development of a hypersensitive resistance response at high inoculum concentrations (108 colony-forming units per mL); (2) lessened severity of disease symptoms at moderate inoculum concentrations (106 and 107 colony-forming units per mL); and (3) reduced growth of avirulent P. s. tabaci in inoculated leaves. The results indicate that essential components of a Pto-mediated signal transduction pathway are conserved in tobacco and should prompt examination of resistance gene function across even broader taxonomic distances.     

湖南烟区土壤交换性钙、镁含量及对烤烟品质的影响

分析了湖南烟区主要土壤类型交换性钙、镁元素含量状况及其对烟叶品质的影响,结果表明:(1)土壤交换性钙、镁含量在不同土壤类型间存在显著性差异,交换性钙含量平均为8.87cmol/kg,以红壤含量最高;交换性镁含量平均为1.16cmol/kg,以黄棕壤含量最高;交换性钙镁比值大小依次为:红壤(11.74)>水稻土(10.25)>黄壤(6.84)>黄棕壤(6.14),在烟叶实际生产中,应重视镁肥在红壤和水稻土中的施用;(2)烟叶钙含量偏高(21.93g/kg±4.37g/kg),烟叶镁含量偏低(2.52g/kg±1.26g/kg),两者均存在广泛的变异性;(3)整体来看,烟叶钙含量随土壤中交换性钙含量的升高和镁含量的降低而显著升高;烟叶镁含量随土壤交换性镁含量的升高而升高,与土壤交换性钙含量的相关性不显著;(4)典型相关分析表明,土壤中交换性镁含量的降低可能引起烟叶钾含量的提高,从而使得烟叶钾素和镁素含量达到较好的平衡;(5)土壤交换性钙、镁含量与烟叶其它化学成分指标的相关分析表明,土壤交换性钙有利于烟株对硼和氯素的吸收,对氮、锌和锰素的吸收则有显著的抑制作用;而土壤交换性镁有利于烟叶总糖、硼素和锰素的积累,对氮、磷、铁和锌素的吸收具有显著的抑制作用。     

Conversion of compatible plant-pathogen interactions into incompatible interactions by expression of the Pseudomonas syringae pv. syringae 61 hrmA gene in transgenic tobacco plants

The hrmA gene from Pseudomonas syringae pv. syringae has previously been shown to confer avirulence on the virulent bacterium P. syringae pv. tabaci in all examined tobacco cultivars. We expressed this gene in tobacco plants under the control of the tobacco Delta0. 3 TobRB7 promoter, which is induced upon nematode infection in tobacco roots (Opperman et al. 1994, Science, 263, 221-223). A basal level of hrmA expression in leaves of transgenic plants activated the expression of pathogenesis-related genes, and the transgenic plants exhibited high levels of resistance to multiple pathogens: tobacco vein mottling virus, tobacco etch virus, black shank fungus Phytophthora parasitica, and wild fire bacterium Pseudomonas syringae pv. tabaci. However, the hrmA transgenic plants were not significantly more resistant to root-knot nematodes. Our results suggest a potential use of controlled low-level expression of bacterial avr genes, such as hrmA, in plants to generate broad-spectrum resistance to bacterial, fungal and viral pathogens.     

A strobilurin fungicide enhances the resistance of tobacco against tobacco mosaic virus and Pseudomonas syringae pv tabaci

The strobilurin class of fungicides comprises a variety of synthetic plant-protecting compounds with broad-spectrum antifungal activity. In the present study, we demonstrate that a strobilurin fungicide, F 500 (Pyraclostrobin), enhances the resistance of tobacco (Nicotiana tabacum cv Xanthi nc) against infection by either tobacco mosaic virus (TMV) or the wildfire pathogen Pseudomonas syringae pv tabaci. F 500 was also active at enhancing TMV resistance in NahG transgenic tobacco plants unable to accumulate significant amounts of the endogenous inducer of enhanced disease resistance, salicylic acid (SA). This finding suggests that F 500 enhances TMV resistance in tobacco either by acting downstream of SA in the SA signaling mechanism or by functioning independently of SA. The latter assumption is the more likely because in infiltrated leaves, F 500 did not cause the accumulation of SA-inducible pathogenesis-related (PR)-1 proteins that often are used as conventional molecular markers for SA-induced disease resistance. However, accumulation of PR-1 proteins and the associated activation of the PR-1 genes were elicited upon TMV infection of tobacco leaves and both these responses were induced more rapidly in F 500-pretreated plants than in the water-pretreated controls. Taken together, our results suggest that F 500, in addition to exerting direct antifungal activity, may also protect plants by priming them for potentiated activation of subsequently pathogen-induced cellular defense responses.     

氮素对不同品种烤烟叶片衰老、光合特性及产量和品质的影响

以豫烟5号、豫烟7号和NC89为材料,研究氮素对不同品种烤烟叶片衰老、光合特性及产量和品质的影响.结果表明：增施氮素可显著增强烤烟叶片超氧化物歧化酶(SOD)活性,降低丙二醛(MDA)含量,提高叶绿素含量,增强光合性能,从而延缓烤烟叶片衰老.与豫烟5号和NC89相比,豫烟7号叶片叶绿素含量较低,光合性能较弱,SOD活性低,MDA含量高,叶片衰老较快.与60和75 kg·hm^-2施N处理相比,45 kg·hm^-2 施N处理的烟叶均价、产值、上等烟比例均最高,且化学品质指标较好,符合优质烟叶要求.表明不同品种烤烟衰老生理特性有明显差异;氮素营养对烤烟叶片衰老、产量和品质有明显的调节作用;适量施氮可提高烟叶品质,获得较高的经济效益.