烟草对烟蚜的抗性品种筛选及抗性机制研究

[目的]探明烟草对烟蚜Myzus persicae(Sulzer)的抗性机制,为烟草抗性品种的选育及烟蚜的综合防治提供理论依据。[方法]采用新叶子圆片法测定烟蚜在20个烟草品种上的发育历期、繁殖力、存活率等,并测定了20个烟草品种鲜叶可溶性蛋白质含量、pH值、叶绿素含量及叶背茸毛数量。[结果]在不同烟草品种上烟蚜的选择性、成虫寿命、繁殖力、若蚜历期及存活率差异显著。其中闽烟38、贵烟3号和云烟97更感虫,而闽烟57、闽烟7号和中烟102具有较强的抗虫性。不同烟草品种鲜叶片中pH值的差异并不显著,但叶背茸毛密度、可溶性蛋白质含量、叶绿素a和叶绿体色素含量差异显著,且与烟蚜成虫量呈极显著正相关,这表明烟蚜更喜食叶背茸毛密度高、可溶性蛋白质含量高、叶绿素含量高的烟草品种。[结论]20个烟草品种中,闽烟57、闽烟7号和中烟102具有较强的抗虫性。选育背茸毛密度低、可溶性蛋白质含量低、叶绿素含量低的品种,可提高烟草对烟蚜的抗性。     

香蕉幼苗三类有机小分子溶质对尖孢镰刀菌侵染的生理响应

为阐明香蕉枯萎病发病机制,研究了尖孢镰刀菌侵染后,香蕉植株中几种对尖孢镰刀菌生长有显著作用的物质(氨基酸、有机羧酸、酚酸)种类和含量的变化。结果表明:(1)病原菌侵染后,伤害逐渐加剧,株高和生物量显著下降。(2)病原菌侵染后,叶片氨基酸总量显著升高,其中丝氨酸、缬氨酸、组氨酸、异亮氨酸和亮氨酸增幅较大,病原菌侵染16 d,其含量分别为侵染前的7.1、6.2、4.4、3.5和2.3倍;而根氨基酸总量开始显著降低,差异逐渐变小。(3)叶片有机羧酸酸含量在病原菌侵染后显著增加,而在根中显著降低。侵染植株叶片中草酸、柠檬酸、苹果酸、琥珀酸和延胡索酸含量分别是未侵染植株叶片的2.6、1.6、1.9、1.8和2.3倍;根中草酸、柠檬酸、苹果酸、琥珀酸和延胡索酸含量分别是未侵染植株的81%、42%、44%、28%和59%。(4)病原菌侵染后,植株叶片和根中酚酸含量都显著升高。叶片中阿魏酸、肉桂酸和水杨酸含量分别是未侵染叶片的2.9、1.7和2.9倍;而根中对羟基苯甲酸和丁香酸含量分别是未侵染根的4.3和1.5倍。研究结果表明,尖孢镰刀菌侵染后,植物与病原菌的相互作用使得植物体内抑菌物质和促菌物质都会相应的增加,植株对病害有一定的抗性,但促菌物质种类和含量较高最终使得感病植株发病。     

PVY和PVS病毒复合侵染对马铃薯光合及营养品质的影响

以2个马铃薯高代品系为实验材料,研究马铃薯病毒Y(PVY)和S(PVS)复合侵染对马铃薯叶片SPAD值、最大净光合速率、表观量子效率、气孔导度、暗呼吸速率、蒸腾速率、光补偿点、胞间CO_2浓度和饱和光强等光合参数,以及马铃薯块茎产量、干物含量、淀粉含量、还原糖含量、粗蛋白含量等产量品质指标的影响。结果表明:(1)田间受到PVY和PVS病毒复合侵染后,马铃薯品系2010-11植株的叶片PVS病毒含量显著低于品系34-2植株,2010-11植株的叶片PVY病毒含量同样低于品系34-2植株,但差异不显著。(2)与对照相比,感病后马铃薯品系34-2和2010-11的平均单株产量分别显著降低48.54%和19.98%,淀粉含量分别降低8.06%和3.38%,但不显著;粗蛋白含量分别显著升高14.05%和29.17%;还原糖含量分别显著降低11.11%和14.29%;34-2干物量含量显著降低6.9%,2010-11干物质含量略降低0.66%。(3)两品系感病植株的光合参数SPAD值分别显著降低13.37%、20.10%;最大净光合速率分别显著降低32.48%和4.54%;其它光合参数变化没有规律性。研究发现,PVY和PVS病毒混合侵染使马铃薯植株叶片叶绿素含量显著降低,进而影响光合作用的正常进行;病毒侵染使块茎中还原糖和淀粉的积累显著受到抑制,但能够促进块茎中粗蛋白的含量显著提高。     

烟草品种、育苗方式和烟蚜来源对烟蚜茧蜂寄生能力的影响

【目的】本研究旨在筛选出适合烟蚜茧蜂Aphidius gifuensis寄生烟蚜Myzus persicae的烟草品种、育苗方式和烟蚜来源,为烟蚜茧蜂人工繁殖和复壮提供科学参考。【方法】采用盆栽法,调查了不同烟草品种(云烟87、K326、翠碧1号和红花大金元)繁殖烟蚜若蚜、不同来源烟蚜(来自烟区、来自非烟区和室内繁殖种群)若蚜和烟草不同育苗方式(土壤育苗和湿润育苗)繁殖烟蚜若蚜时,烟蚜茧蜂成蜂对烟蚜若蚜的寄生率以及成蜂羽化率、寿命、体型大小和雌蜂比。【结果】结果表明,不同烟草品种繁殖烟蚜若蚜对烟蚜茧蜂成蜂寄生率存在显著影响。其中,在红花大金元和翠碧1号繁殖烟蚜上的烟蚜茧蜂成蜂寄生率分别比在K326繁殖烟蚜上的烟蚜茧蜂成蜂寄生率高19.00%和14.00%,但对烟蚜茧蜂的其他指标没有显著影响;不同烟蚜来源对烟蚜茧蜂寄生率也存在显著影响,其中,烟蚜茧蜂成蜂对非烟区烟蚜若蚜和烟区烟蚜若蚜的寄生率比对室内繁殖种群烟蚜若蚜的寄生率分别高20.25%和16.75%,但对烟蚜茧蜂成蜂的羽化率、寿命、体型大小和雌蜂比没有显著影响;烟草不同育苗方式对烟蚜茧蜂成蜂的寄生率无显著影响。【结论】烟蚜茧蜂对烟蚜...     

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。     

烟蚜在烤烟田分布动态的地统计学分析

烟蚜属半翅目蚜科,是烟田的重要迁飞性害虫,成蚜和若蚜聚集于烟叶幼嫩部位,吸食植物汁液,滋生霉污病并传播烟草病毒病害,造成产量和质量损失.本文在湖北恩施地区选择烤烟田对烟叶从移栽至中部烟叶开始采收阶段的田间有翅烟蚜和无翅烟蚜的空间分布和发生动态进行调查,并通过地统计学方法分析其半变异函数特性,模拟其田间迁移模式.结果表明:恩施烟区有翅烟蚜种群动态为双峰曲线,烟叶移栽后第3周和烟叶打顶后第2周为发生高峰,呈现随机、聚集、随机、聚集、随机5步过程;无翅烟蚜种群动态为单峰曲线,烟叶打顶前为发生高峰,呈现随机、聚集、随机3步过程;人为因素和寄主特性对其种群密度影响较大;空间分布模拟插值图可以清晰反映出田间烟蚜的发生动态,结合Pearson相关分析发现,有翅蚜迁入高峰期,烟蚜种群数量小并高度集中,构成了田间烟蚜的虫口基数,是烟蚜防治的关键时期.     

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。     

烟草水浸提液对葡萄根瘤蚜侵染危害的控制效应

【目的】检疫害虫葡萄根瘤蚜Daktulosphaira vitifoliae已经在我国多个地区葡萄园发现为害, 直接影响葡萄生长; 前期实验发现烟草水浸提液可有效控制离体根上根瘤蚜的存活率, 本研究进一步开展盆栽验证, 探讨烟草水浸提液对葡萄根瘤蚜侵染的控制效应及葡萄植株生长抑制的缓解作用。【方法】以两年生温室盆栽‘巨峰’自根苗为实验材料, 接种根瘤蚜虫卵35 d后进行烟草水浸提液处理, 处理后测定供试植株的根结数、生长量、根系活力、叶片光合速率及叶绿素荧光等指标。【结果】20 mg/mL和50 mg/mL的烟草水浸提液对根瘤蚜均有一定程度的抑制作用, 施药21 d后, 葡萄根部的新增根结数分别比侵染对照下降了42.9%和52.8%。烟草水浸提液处理还在一定程度上缓解了根瘤蚜侵染对植株的光合能力和荧光的抑制作用。20 mg/mL和50 mg/mL烟草水浸提液处理的株高分别比侵染对照提高了57.1%和7.7%; 根瘤蚜侵染降低了土壤中真菌、细菌和放线菌的数量, 烟草水浸提液处理进一步降低了真菌和放线菌的数量, 降低了由微生物带来的次生侵染几率。【结论】烟草水浸提液对葡萄根瘤蚜的侵染具有控制效果, 并可对葡萄根瘤蚜侵染已造成的寄主危害有一定的缓解作用。     

一种扩繁烟蚜茧蜂的载体植物适合性评价

为评估平卧菊三七作为载体植物扩繁烟蚜茧蜂的适合性,测试了烟蚜在平卧菊三七、以及常见寄主植物烟草、茄子和二年生萝卜共4种寄主植物上的发育历期和繁殖力等,获得了净增殖率、周限增长率、内禀增长率、平均世代周期、种群加倍时间等主要生命表参数,比对了不同载体植物上的烟蚜对烟蚜茧蜂个体发育的影响。结果显示:这4种寄主植物上烟蚜的发育历期为二年生萝卜(22.79 d)平卧菊三七(22.22 d)烟草(22.01 d)茄子(18.92 d),茄子上最短,其他三种寄主植物上无显著差异;单头烟蚜总产仔量为二年生萝卜(63头)平卧菊三七(52头)茄子(43头)烟草(41头);内禀增长率rm值为茄子(0.283)二年生萝卜(0.278)平卧菊三七(0.277)烟草(0.255)。表明相同条件下,相对于烟草,烟蚜偏好取食平卧菊三七;平卧菊三七作为载体扩繁出的烟蚜茧蜂僵蚜,体型与烟草、二年生萝卜扩繁者的差异不显著。平卧菊三七可用作大量扩繁烟蚜及烟蚜茧蜂的载体植物。     

番茄环纹斑点病毒与马铃薯Y病毒复合侵染烟草的细胞病理特征

在自然情况下, 番茄环纹斑点病毒(TZSV)和马铃薯Y病毒(PVY)通常复合侵染同一植株。该文首次报道了TZSV和PVY复合侵染烟草(Nicotiana sp.)植株的细胞病理特征, 并与单独侵染进行了比较分析。复合侵染的烟草植株细胞中, TZSV病毒颗粒明显增多, 并聚集于囊膜内形成包涵体, 与PVY的风轮状及片层状内含体和病毒颗粒聚集体交叉分布于细胞质(内含线粒体明显增多)中, 线粒体、叶绿体和细胞核结构较完整; 两种病毒的颗粒、包涵体和内含体数量均较单一侵染增多, 且对寄主亚细胞结构的破坏较单一侵染为轻, TZSV和PVY及其与寄主的互作可能存在协生作用。     

Effects of the pyrethroid deltamethrin on the acquisition and inoculation of viruses by Myzus persicae

The pyrethroid, deltamethrin, alone or as an emulsifiable formulation, hindered infection of healthy plants with the persistent beet mild yellowing virus (BMYV) and both acquisition of, and infection with, the non-persistent potato virus Y (PVY) and the semi-persistent sugar beet yellows virus (BYV) by Myzus persicae in glasshouse tests.
Another pyrethroid, RU-15525, also protected against infection with PVY. Even sub-lethal amounts of deltamethrin decreased virus transmission by rapidly incapacitating the aphids, the effect being least with aphids most resistant to organophosphorous insecticides and to certain pyrethroids including deltamethrin. Demeton-S-methyl hindered infection only with BMYV. This work shows that deltamethrin restricts transmission of persistent, semi-persistent and perhaps more importantly of non-persistent viruses in the glasshouse, and has potential for doing the same in the field.     

烟蚜茧蜂寄生对烟蚜生长发育和繁殖的影响

【目的】为探究烟蚜茧蜂Aphidius gifuensis对烟蚜Myzus persicae寄生后烟蚜生长发育和繁殖影响及其在烟蚜防控中的作用。【方法】采用室内叶片培养皿法,测定了不同龄期烟蚜(1-4龄若蚜及成蚜)被烟蚜茧蜂寄生后烟蚜当代(F₀)及后代(F₁)的发育历期、寿命、产仔量。【结果】烟蚜1龄若蚜被烟蚜茧蜂寄生后,1龄若蚜历期受到显著影响,较未被寄生对照缩短了0.65 d (33.00%),而2-4龄若蚜期和成蚜历期未受显著影响;2龄若蚜被寄生后,4龄若蚜和成蚜历期均受到显著影响,较未被寄生的对照分别缩短了1.50 d (100.00%)和0.83 d (100.00%),而2和3龄若蚜期未受显著影响;3龄若蚜被寄生后,4龄若蚜和成蚜期均受到显著影响,较未被寄生对照分别缩短了1.50 d (100.00%)和0.83 d (100.00%),而3龄若蚜期未受显著影响。2龄若蚜被寄生后烟蚜的寿命和产仔量均受到显著影响,寿命较未被寄生对照缩短了8.39 d(54.00%),每雌产仔量较未被寄生对照减少了48.67头(100.00%)。此外,2-3龄若蚜被寄生后其后代(F₁)1龄若蚜历期受影响最大,较未被寄生烟蚜后代1龄若蚜期缩短了0.80 d(40.00%),其F₁代平均寿命较未被寄生烟蚜后代平均寿命延长了5.72 d(41.20%),但其产仔量与对照差异不显著。【结论】不同龄期烟蚜被烟蚜茧蜂寄生后,其发育历期和寿命比未被寄生的缩短,产仔量比被未寄生的少,但其F₁代平均寿命比未被寄生后代烟蚜的长且其产仔量未受显著影响。当代2龄若蚜期是控制烟蚜增长的关键时期。这些结果对确定烟蚜茧蜂防治烟蚜适期及认识其机理具有重要参考意义。     

Correlation of viral RNA biosynthesis with glucose-6-phosphate dehydrogenase activity and host resistance

Changes in glucose-6-phosphate dehydrogenase (G6P DH; EC 1.1.1.49) activity caused by infection of tobacco ( Nicotiana tabacum L.) leaves with potato virus Y (PVY), cucumber mosaic virus, potato virus X, tobacco rattle virus and turnip mosaic virus, the subcellular localisation of G6P DH isozymes in mesophyll protoplasts derived from healthy and PVY-infected tobacco leaves, as well as G6P DH control and the relationship of its isozymes with the degree of tobacco resistance to PVY multiplication, were studied. The activities of G6P DH were markedly increased in locally and systemically infected leaves and the time courses of the activity linearly correlated with those of virus multiplication. In leaves infected with PVY, the activity time courses of the crude and the partially purified G6P DH were coincident. This probably indicates the involvement of coarse regulation of the enzyme. PVY content linearly correlated with enhanced G6P DH activity in leaf discs derived from susceptible, tolerant and resistant cultivars of tobacco. The increased activity of the enzyme in infected protoplasts and plant tissues was predominantly caused by the increased activity of chloroplastic isozymes. This was confirmed by the specific staining of isozymes after electrophoretic separation of chloroplastic proteins of tobacco leaves. These findings enable the degree of resistance to virus multiplication to be quantified for the use of gene manipulation and breeding.     

微波辐射对桃蚜生长发育和繁殖的影响

【目的】研究筛选对桃蚜Myzus persicae有致死作用的安全微波频率和照射时长,以为探究新型物理防蚜技术,弥补化学防治上的缺陷提供参考依据。【方法】在暗箱中,应用微波发射仪分别发射1375, 2 750, 5 500和11 000 MHz 4个不同频率的微波照射桃蚜1日龄无翅成蚜,每个频率的照射时长分别为15, 30, 60和120 s;照射后在人工气候箱中饲养,分别于照射后8, 24, 48和72 h观察其生长发育及繁殖状况,统计桃蚜死亡率、繁殖力(累计产蚜量)及子代有翅蚜率。【结果】4个不同频率的微波分别在4个不同照射时长下,对桃蚜1日龄无翅成蚜的死亡率、繁殖力和子代翅型分化都有不同程度的影响。照射后72 h, 5 500 MHz微波照射时间为15 s时对桃蚜1日龄无翅成蚜的致死作用最强,死亡率达到55.00%,在照射时间为30和120 s时可抑制子代桃蚜向有翅蚜的分化。2 750 MHz微波照射30和60 s时促进桃蚜1日龄成蚜繁殖,照射30 s时繁殖力最强,而照射15和120 s时却表现为抑制繁殖,且2 750 MHz微波照射30 s能抑制子代桃蚜向有翅蚜分化。【结论】微波辐射能够影响桃蚜1日龄成蚜的存活、繁殖和子代翅型分化。本研究初步筛选出了对桃蚜1日龄无翅成蚜有致死作用的微波频率和照射时长。     

APHID BEHAVIOUR ON HEALTHY AND ON YELLOWS-VIRUS-INFECTED SUGAR BEET

Myzus persicae Sulz., M. ascalonicus Doncaster, Aphis fabae Scop, and Aulacorthum solani Kalt., when caged on sugar-beet leaves in the glasshouse preferred yellows-virus-infected leaves to healthy ones; they chose those with the most severe symptoms on which they bred more rapidly and lived longer than on green leaves. M. persicae behaved similarly on whole plants in the glasshouse. The previous host influenced the aphid's preference. Differences between the multiplication rates of aphids on healthy plants of inbred sugar-beet varieties were eliminated or reversed by infection with yellows virus.
Spraying healthy plants with either sugar solutions or hydrolysate of casein increased the multiplication rate of M. persicae , but much less than did virus infection.     

Changes in Glucose-6-Phosphate Dehydrogenase, Ribonucleases, Esterases and Contents of Viruses in Potato Virus Y Infected Tobacco Superinfected with Tobacco Mosaic Virus

Effects of the superinfection with tobacco mosaic virus (TMV) on susceptible tobacco plants infected with potato virus Y (PVY) were determined. Dynamic changes in the TMV and/or PVY contents, the ribonucleases (RNases), the phosphomonoesterase (PME), the phosphodiesterase (PDE) and the glucose-6-phosphate dehydrogenase (G6P DH) activities were studied. The PVY infection caused a substantial reduction in the multiplication of TMV. The content of TMV in the PVY inoculated leaves amounts to 6 and 9 % in the PVY systemically infected leaves when compared with single TMV. Surprisingly, the challenging virus (TMV) enhanced the content of inducing virus (PVY) in the locally inoculated leaves up to 130 – 141 %. In contrast, the reduction of PVY content down to 35 – 40 % by TMV was seen in the PVY systemically infected leaves. The activities of the RNase, the PME, the PDE and the G6P DH were increased (when compared with the healthy plants) during the acute phase of single virus multiplication (PVY or TMV). The increase in the activities of the enzymes in the leaves with mixed infection was at least as high as the sum of the increases of single infections. Moreover, a higher increase than the sum was seen for G6P DH and PDE (by about 20 – 35 %). This revised version was published online in July 2006 with corrections to the Cover Date.     

ToCV单独侵染和TYLCV&ToCV复合侵染番茄植株上烟粉虱寄主适应性及寄主植物营养成分含量和防御反应变化

【目的】本研究以番茄褪绿病毒(tomato chlorosis virus, ToCV)和番茄黄化曲叶病毒(tomato yellow leaf curl virus, TYLCV)为主体,旨在明确ToCV单独侵染及TYLCV&ToCV复合侵染对烟粉虱Bemisia tabaci MED隐种寄主适应性的影响,并从寄主植物营养成分和防御角度解析不同番茄病毒侵染对烟粉虱MED隐种寄主适应性影响的生理机制。【方法】ToCV单独侵染和TYLCV&ToCV复合侵染番茄植株后,统计分析番茄植株上烟粉虱MED隐种成虫存活率和产卵量以及番茄植株中氨基酸和总糖含量;通过RT-qPCR技术检测番茄植株茉莉酸(JA)信号通路关键基因(FAD7和PI II)以及水杨酸(SA)信号通路关键基因(NPR1和PR1)的表达模式。【结果】相对于取食健康番茄植株的烟粉虱成虫,取食番茄病毒侵染的番茄植株烟粉虱MED隐种成虫的存活率和产卵量均显著降低,其中以TYLCV&ToCV复合侵染番茄植株为寄主时,烟粉虱MED隐种成虫的存活率和产卵量均达到最低水平。TYLCV&ToCV复合侵染后,番茄植株中总氨基酸含量、14种水解氨基酸含量以及总糖含量低于ToCV单独侵染番茄植株。ToCV单独侵染和TYLCV&ToCV复合侵染番茄植株后,FAD7和PI II的表达量均显著降低,并且2个基因在TYLCV&ToCV复合侵染植株中的表达水平最低;然而,NPR1和PR1的表达水平在ToCV单独侵染和TYLCV&ToCV复合侵染番茄植株中均有上升趋势,TYLCV&ToCV复合侵染番茄植株中NPR1表达水平和ToCV单独侵染番茄植株中PR1表达水平均显著高于健康番茄植株中的。【结论】ToCV单独侵染和TYLCV&ToCV复合侵染均能够明显降低番茄植株上烟粉虱MED隐种的寄主适应性,且TYLCV&ToCV复合侵染更不利于烟粉虱MED隐种生存;相对于健康番茄植株,ToCV单独侵染和TYLCV&ToCV复合侵染番茄植株营养成分与防御系统发生了变化且存在差异。研究结果为揭示烟粉虱与植物病毒互作提供了参考。     

Glucose-6-Phosphate Dehydrogenase/6-Phosphogluconate Dehydrogenase Ratio and the Glucose-6-Phosphate, 6-Phosphogluconate and Fructose-6-Phosphate Contents in Tobacco Plants Infected with Potato Virus Y

The ratio of activities of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase (G6P DH/6PG DH), and the contents of glucose-6-phosphate (G6P), 6-phosphogluconate (6PG) and fructose-6-phosphate (F6P) were studied at various stages of potato virus Y (PVY) multiplication in Nicotiana tabacum cv. Samsun. G6P DH/6PG DH increased through the experiment from 0.42 to 0.53 in leaves of healthy tobacco, and up to 0.59 in PVY systemically infected leaves. However, these ratios in the ruptured protoplast preparations, and the chloroplast and cytosol fractions of healthy protoplasts were similar to that from infected ones. The ratio lower than 1, found in the healthy and/or PVY- infected leaf tissues and in the infected protoplasts as well, confirms the assumption that G6P DH is the control enzyme of oxidative pentosephosphate pathway not only in the healthy but also in the infected plants. The contents of G6P, 6PG and F6P in the period of the highest PVY multiplication were strongly decreased (to 30 – 50 % when compared with control healthy leaves) and were negatively correlated with the G6P DH and 6PG DH activities.     

温度对桃蚜和马铃薯长管蚜实验种群生命表参数的影响

【目的】桃蚜Myzus persicae (Sulzer)和马铃薯长管蚜Macrosiphum euphorbiae (Thomas)是2种主要的马铃薯害虫。本研究旨在明确温度对这两种马铃薯蚜虫生长发育、存活、繁殖及种群增长的影响。【方法】在室内测定了5个温度（10, 15, 20, 25和30℃）下桃蚜和马铃薯长管蚜的生长发育、存活和繁殖指标,并组建了4个恒温条件下（10,15,20和25℃）的实验种群生命表。【结果】在10~25℃范围内,2种蚜虫的若蚜期、世代历期、成蚜寿命和产蚜期等均随温度的升高而缩短,而30℃高温抑制了其发育、存活和繁殖。2种蚜虫的平均世代历期（T）随温度的升高而缩短,桃蚜和马铃薯长管蚜分别从10℃的30.08 d和35.35 d缩短至25℃的14.28 d和12.95 d。桃蚜的净增殖率（R₀）在15℃时最高（86.00）,其次为20℃（73.75）,再次为25℃（62.49）,最低为10℃（51.00）;马铃薯长管蚜的R0在15℃最高（58.97）,其次为10℃（51.98）,再次为20℃（48.94）,最低为25℃（12.36）。桃蚜的内禀增长率（r_m）随温度的升高而增大,从最小10℃的0.1307增大到25℃的0.2896;马铃薯长管蚜的r_m在20℃时最大（0.2182）,其次为25℃（0.1942）,再次为15℃（0.1485）,最小为10℃（0.1118）。在相同的温度下,桃蚜的发育速率、净增殖率和内禀增长率均高于马铃薯长管蚜。【结论】温度对2种马铃薯蚜虫的生长发育、存活、繁殖及种群增长有显著的影响,桃蚜在马铃薯上的种群增长能力强于马铃薯长管蚜。这一结果为马铃薯蚜虫预测模型的建立奠定了必要的基础,并解释了桃蚜在马铃薯上发生数量多于马铃薯长管蚜的原因。     

Systemic Infection of Tobacco by Pepper Veinal Mottle Potyvirus (PVMV) Depends on the Presence of Potato Virus Y (PVY)

In single inoculations, both PVY and PVMV replicated in inoculated leaves of Nicotiana tabacum cv. ‘Xanthi nc’ plants, but only PVY infected the tobacco plants systemically, whereas PVMV caused localized infection. A mixed infection by the PVY-To72 and PVMV-type strains was experimentally realized in ‘Xanthi nc’ plants. In the presence of PVY, PVMV migrated systemically into the upper leaves of the tobacco plant, as was proved by back inoculation. It would appear that in tobacco, PVY acts as a “helper” virus, providing PVMV with the necessary component factor for migration. In extracts from the co–infected leaves. Immune Electron Microscopy (IEM) revealed phenotypic mixed particles which contained a mixture of coat proteins of PVY and PVMV. The role of the structural and functional interactions between the two viruses, which enable PVMV to migrate systemically in tobacco plants, is discussed.