褐飞虱五龄若虫翅芽长度与成虫翅型关系的研究

褐飞虱饲养于不同水稻品种、不同生育期以及不同种群密度条件下,5龄若虫翅芽长度与成虫翅型具有稳定的相关性：翅芽长于1．10mm羽化后为长翅型雌虫,介于0．96～1．09mm之间为长翅型雄虫或短翅型雌虫,小于0．95mm为短翅型雄虫。根据5龄若虫翅芽长度结合外生殖器特征,编制了成虫翅型检索表。由此,可在5龄若虫期预测成虫的翅型和种群盛衰的趋势。     

稻飞虱翅型纯系后代个体的翅型分化对光周期变化不敏感

【目的】为了明确光周期和遗传因子在稻飞虱翅型分化中的作用, 研究了3种稻飞虱（褐飞虱Nilaparvata lugens、白背飞虱Sogatella furcifera和灰飞虱Laodelphax striatellus）翅型纯系或近纯系在不同光照时数下的翅型分化比率。【方法】以经过5~45代连续翅型筛选后的褐飞虱、白背飞虱和灰飞虱的长翅型和短翅型纯系或近纯系为材料, 在室内分别测定了其在长光照（16和20 h）、短光照(4~12 h)和正常光照(14 h) 3类光周期条件下饲养后, 雌、雄成虫中长翅和短翅个体出现的比率及存活率。【结果】白背飞虱和灰飞虱的长翅型纯系M♂×M♀或短翅型纯系B♂×B♀在不同光周期下的翅型比率均无显著差异（P>0.05）。褐飞虱短翅型近纯系B♂×B♀的雌虫短翅率和成虫总短翅率在不同光周期下也无显著差异（P>0.05）, 但雄虫短翅率在正常光照14 h和短光照4 h下显著高于长光照20 h下的（P<0.05）。当褐飞虱短翅型达到纯系后, 其后代翅型在6~16 h光照条件下无显著差异。褐飞虱长翅型近纯系M♂×M♀的后代虽有短翅个体出现, 但是雌虫和雄虫的各自短翅率在不同光周期下无显著差异（P>0.05), 仅总体短翅率在12 h光照条件下的显著高于16 h下的（P<0.05）。褐飞虱长、短翅型杂交筛选品系M♂×B♀的雌虫短翅率随光照时数的延长而升高; 灰飞虱杂交筛选品系M♂×B♀的短翅雄虫随光照时数的缩短而增多（P<0.05）, 但当筛选代次达到45代时, 这种趋势不再显著。3种稻飞虱长翅型和短翅型纯系或近纯系若虫的存活率会稍低于长、短翅型杂交后代的存活率, 但长、短翅型品系的存活率在6~16 h光照条件下差异不显著(P>0.05)。【结论】稻飞虱翅型分化对光周期的反应受飞虱本身遗传背景的影响, 翅型纯系后代个体的翅型分化对光周期变化不敏感。     

三种稻飞虱翅型分化的遗传分析

为了明确褐飞虱Nilaparvata lugens、 白背飞虱Sogatella furcifera和灰飞虱Laodelphax striatellus 3种稻飞虱翅型分化的遗传规律与差异, 采用翅型筛选与杂交遗传的实验方法, 研究了3种飞虱在秧苗期水稻上的翅型选择响应与杂交遗传规律。结果表明： 3种稻飞虱的翅型具有较强的选择响应, 并且长翅型纯系在白背飞虱中最易筛选得到, 灰飞虱的次之, 而褐飞虱的最难。3种稻飞虱的长翅(M)雄虫与短翅(B)雌虫配对(M♂×B♀)筛选3~5代后, 95%~100%的雄虫和雌虫分别稳定为长翅型和短翅型。筛选和杂交实验结果表明, 褐飞虱的翅型决定基本符合常染色体上的一对等位基因调控的从性性状遗传规律, 雄虫中长翅为显性, 而雌虫中短翅为显性。翅型的表型还受除基因型外的其他条件的影响, 利用长翅雄虫与长翅雌虫后代中出现的极少数的短翅雄虫与短翅雌虫进行配对, 其后代中各翅型出现的比率与长翅雌虫和长翅雄虫配对的无显著差异; 同样, 在短翅雄虫与短翅雌虫配对的后代中也有相同的结果。白背飞虱和灰飞虱在该筛选条件下很少有短翅雄虫出现, 两者翅型的遗传调控较为相似, 可用由两对等位基因控制的性状来解释筛选和杂交实验的结果, 其中一对等位基因位于性染色体上, 调控雄性的翅型, 且长翅为显性; 另一对位于常染色体上, 调控雌性的翅型, 且短翅为显性。据此认为, 3种飞虱翅型决定基因的显隐性在不同性别间的差异, 以及翅表型与基因型的不一致性, 是稻飞虱种群在不同条件下均可灵活调控翅型的重要遗传机制。     

褐飞虱翊型分化遗传规律的研究

以褐飞虱Nilaparvata lugens (Stal)长翅型(macroptery,简称M)、短翅型(brachyptery,简称B)的遗传纯系为实验材料,进行亲本、稻株生育期、虫口密度三因子交互实验。结果表明：(1)在环境条件(指稻株生育期、虫口密度等)一致时,B♀×B♂、B♀×M♂、M♀×B♂、M♀×M♂四种亲本组合的F1代短翅型成虫百分率分别为：98%、92%、64%、29%,各亲本组合间差异极显著;(2)亲本相同时,将F1代褐飞虱初孵若虫多头词养(多于l0头/株)在黄熟期稻株上,其长翅型雌、雄成虫百分数均高于灌浆期稻株上;(3)单头饲养实验中发现,不论亲本组合、稻株生育期如何,雌虫绝大多数分化为短翅型,而雄虫则几乎全为长翅型。这表明褐飞虱的翅型分化遗传由一个受多种因子影响的调控体系决定,且调控作用与性别有关。     

褐飞虱的交配行为及与保幼激素滴度的关系

受5龄末期和羽化初期较高保幼激素滴度的影响,褐飞虱Nilaparvata lugens(Stal)短翅型成虫性成熟比长翅型成虫早40～50h。5日龄前短翅型雌成虫的交配成功率较高,雄成虫的交配竞争能力较强;1、2日龄的长翅型雌成虫不交配,5日龄后长翅型成虫的交配能力渐渐超过短翅型成虫。实验种群的交配持续时间为(70.38±41.77)s;交配成功率为51.63%;雌、雄虫均可重复交配。一日中0～4h和10～14h交配成功率较高。     

高温对稻褐飞虱发育与生殖的影响

通过高温处理及交配产卵实验,探讨了高温对稻褐飞虱Nilaparvata lugens (Stal)发育与生殖的影响。研究了不同高温条件对褐飞虱若虫发育历期、产卵量、产卵前期、寿命等生物学特性的影响。34℃以上高温导致褐飞虱若虫发育历期延长。高温处理4龄若虫使羽化后的雌成虫产卵量减少。高温处理不同日龄雌成虫也致使其产卵量减少,其中以1日龄短翅型、3日龄长翅型的产卵量影响最大。高温处理后褐飞虱寿命缩短。高温恒温处理,对短翅型雌成虫的产卵前期影响不大,但能延长长翅型雌成虫的产卵前期;而高温变温处理致使短、长翅型雌成虫的产卵前期均延长。高温变温对褐飞虱生殖的影响程度大于高温恒温。高温处理组雌、雄成虫与对照组相应的成虫交配试验表明,高温对雌性的影响大于雄性。实验初步确定34℃为对褐飞虱发育与生殖产生影响的临界温度。     

近零磁场对褐飞虱翅型分化、趋光性及飞行能力的影响

【目的】地磁场(geomagnetic field,GMF)不是恒定不变的,而是随时间和空间时刻变化的。目前,动物对磁场变化的响应研究主要集中于迁徙性动物地磁定向导航中的磁感受方面,而迁徙性动物迁出地和迁入地之间地磁场强度差异对动物生理和行为潜在的磁场效应尚不明确。【方法】迁飞性昆虫褐飞虱Nilaparvata lugens试虫采自江苏省农业科学院试验田。本文采用亥姆霍兹线圈室内模拟近零磁场(near-zero magnetic field,NZMF)和GMF,调查了褐飞虱成虫在NZMF和GMF下的翅型分化、趋光性和飞行能力。【结果】结果表明,与GMF相比,NZMF显著提高了褐飞虱雄成虫短翅型比例(6. 4%)(P <0. 05),但对雌成虫长翅型比例影响不显著(P> 0. 05);对于长翅雌成虫,NZMF显著提高了其2日龄成虫的上灯比例(55%)(P <0. 05),但显著降低了其4日龄成虫的上灯比例(22%)(P <0. 05),对趋光性的影响总体呈现出随着龄期先增强后减弱的效应。NZMF对长翅雄成虫趋光性的影响也呈现出相同的效应,但对各日龄成虫的影响不显著(P> 0. 05); NZMF显著缩短了2日龄长翅雄成虫的飞行时间(46%)(P <0. 05),并显著提高了长翅雌成虫(65%)和长翅雄成虫(101%)的飞行速度(P <0. 05)。此外,GMF对照组的褐飞虱长翅雄成虫飞行速度显著低于长翅雌成虫(96%),而NZMF处理组中二者无显著差异。【结论】结果说明,近零磁场可提高褐飞虱成虫短翅比例,对长翅成虫趋光性的影响呈现出基于龄期增长先增强后减弱的效应,并在未影响长翅成虫飞行距离的情况下,改变了其飞行策略,即提高飞行速度,同时缩短飞行时间。     

褐飞虱体内保幼激素滴度变化及其与翅型分化的关系

用高压液相色谱及放射化学法,分别测定了褐飞虱Nilaparvata lugens 1～5龄若虫体内的保幼激素滴度与保幼激素酯酶活性变化,并用保幼激素类似物(ZR-515)进行体表点滴加以验证。结果表明,褐飞虱雌、雄4龄若虫期及雄虫的5龄若虫初期,短、长翅型间体内保幼激素滴度差异明显,可以认为该阶段是其翅型分化的关键时期。     

“秕谷草-伪褐飞虱-中华淡翅盲蝽”载体植物系统的可行性

为明确用于防治稻飞虱的“秕谷草-伪褐飞虱-中华淡翅盲蝽”载体植物系统的可行性,本文开展了靶标作物水稻、载体植物秕谷草和靶标害虫褐飞虱、替代猎物伪褐飞虱组合对中华淡翅盲蝽成虫形态、种群增长参数、产卵选择性和取食选择性的影响研究.结果表明: 中华淡翅盲蝽水稻种群(取食褐飞虱卵)的雌雄成虫个体均显著大于秕谷草种群(取食伪褐飞虱卵).取食褐飞虱卵的中华淡翅盲蝽种群增长参数单雌产卵量、净增长率、内禀增长率、周限增长率明显高于取食伪褐飞虱卵的种群,但取食伪褐飞虱卵也有较高的种群增长能力,足以扩繁种群.对于靶标作物水稻和载体植物秕谷草,无论是水稻种群还是秕谷草种群均偏好在水稻上产卵.同时,2个种群的雌虫、雄虫和若虫对褐飞虱卵和伪褐飞虱卵捕食量没有显著性差异.在上述研究基础上,讨论了在田间建立“秕谷草-伪褐飞虱-中华淡翅盲蝽”载体植物系统的可行性.     

转基因抗虫水稻MSA和MSB对非靶标害虫褐飞虱和白背飞虱的影响

本文报道了转SCK+cry1Ac双基因抗虫水稻MSA和MSB对非靶标害虫褐飞虱Nilaparvata lugens 和白背飞虱Sogatella fucifera生物学及田间发生动态的影响。与亲本明恢86相比,MSA对两种飞虱若虫发育历期、初羽化成虫鲜重、羽化率、短翅率、成虫产卵量、卵受精率、单雌子代数及发育进度等生物学指标均无明显影响,而MSB虽然对多数指标影响不明显,但可以引起白背飞虱初羽化雌虫鲜重与短翅率显著下降,还引起褐飞虱初羽化雄虫鲜重明显减轻。在近距离（株间距约 8 cm）寄主选择实验中,褐飞虱对MSA和MSB无明显选择性,而白背飞虱若虫和成虫均明显趋向两种转基因水稻。田间小区实验表明MSB上的稻飞虱（主要为白背飞虱）密度一般低于亲本明恢86,但差异不显著,提示转基因水稻MSB引发非靶标害虫稻飞虱灾变的风险较小。     

不同地理种群褐飞虱的抗逆性

研究了不同地理种群褐飞虱对水稻抗性品种、若虫高密度、高温、饥饿和杀虫剂等逆境条件的抗性。结果表明,广西和云南种群褐飞虱对抗虫品种的适应性比浙江种群强而广,浙江种群只能适应抗虫品种ＩＲ２６而广西和云南种群则还能适应抗性更高的ＡＳＤ７和Ｒａｔｈｕ Ｈｅｅｎａｔｉ。广西和云南种群较能适应高密度环境,而浙江种群的适应性较差,其雌虫短翅率与若虫密度呈显著负相关。虽然广西和云南种群对高温的忍受性比浙江种群的强     

褐稻虱饲料稻株中数种氨基酸的营养效应

本研究初步证实饲料稻株中甘氨酸、赖氨酸和酪氨酸含量的高低,同褐稻虱(Nilaparvata lugens Stal)的发育进度、存活率、短翅型出现率和单雌产卵量关系极为密切,它们是褐稻虱赖以正常生长发育和繁殖的重要氨基酸。     

褐稻虱取食试验及防治探讨

本文用茚三酮法, 以褐稻虱Nilaparvata lugens(stal)排泄的蜜露面积来测定其相对取食量.试验表明:取食量随虫期增大, 逐日取食分布各虫期呈现明显的峰期(图3);发育历期与累积取食量成幂函数关系: N(t)=0.0531t^2.298式中N(t)=累积取食量, t=发育历期(天);褐稻虱各虫期取食率的变化;若以一龄若虫为1计算, 一一四龄若虫取食量比分别为1:1.66:2.10:3.16:10.26, 成虫为73.19;羽化后8天, 短翅型雌虫日均取食量比长翅型雄虫大6.33倍;按褐稻虱的取食行为, 化学防治适期以世代成虫初见期为宜.     

褐飞虱致害性变异过程及其体内酶的变化

在室内连续用具不同抗虫基因的水稻品种TNl、IR26、Mudg。和ASD7、单管饲养褐飞虱(Nilaparvata lugens)种群,研究它对抗虫水稻品种的适应过程及其体内酶的变化规律。 结果表明：褐飞虱在抗虫品种上取食2代的若虫存活率、若虫历期和短翅成虫体重均明显比取食感虫品种TNl的低,第3代以后与取食TNl者基本相同。第2代是褐飞虱适应抗虫品种的关键期。天冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)和丁-谷氨酰基转移 酶(GGT)的活性在关键的第2代最低,而超氧物歧化酶(SOD)和过氧化氢酶(CAT)的含量增加。褐飞虱在适应抗虫品种以后体内天冬氨酸氨基转移酶活性明显提高。     

共生菌在褐飞虱致害性变化中的作用

研究了不同虫源和致害性褐飞虱Nilaparvata lugens种群体内共生菌数量动态及其对褐飞虱在抗虫品种上的取食选择、生长发育、繁殖以及氨基酸转移酶活性的影响。结果表明,褐飞虱田间种群的致害性与其体内共生菌数量有关。广西南宁种群雌成虫体内的共生菌数量显著地高于浙江杭州和龙游两个虫源的雌成虫体内共生菌数量,而已纯化的3个不同致害性生物型体内的共生菌数量无显著差异。取食抗性品种能显著减少生物型Ⅰ雌成虫体内的共生菌数量。缺乏共生菌时,生物型Ⅰ、Ⅱ若虫对水稻品种TN1和ASD7的选择性增大,而对Mudgo的取食选择性下降。尽管缺共生菌的3个生物型在已适应的和不适应的感虫和抗虫品种上的若虫存活率和雌成虫产卵量均下降,若虫历期明显延长,但在已适应品种上的变化程度明显小于在不适应的抗虫品种上的变化程度。共生菌还明显影响成虫体内丙氨酸氨基转移酶和天门冬氨酸氨基转移酶的活性。这些结果证明体内共生菌的数量和质量在褐飞虱对水稻致害性的变化中发挥了重要作用。     

稻田氮肥施用量对黑肩绿盲蝽捕食功能的影响

在实验室条件下研究了黑肩绿盲蝽Cyrtorhinuslividipennis Reuter在不同含氮量稻株上对褐飞虱Nilaparvata lugens Stal卵和低龄若虫的捕食能力、对褐飞虱卵的捕食功能反应以及褐飞虱蜜露和水稻伤流液对其捕食 能力的影响。结果表明,黑肩绿盲蝽对褐飞虱卵和若虫的捕食量均与寄主植物的含氮量呈显著 负相关。黑肩绿盲蝽在相同氮肥施用量的稻株上连续饲养2代后对褐飞虱卵的捕食能力没有改变 。黑肩绿盲蝽对褐飞虱卵的功能反应呈Holling Ⅱ型方程,其参数瞬时发现率(a)和处置时间(T_h)只与寄主含氮量有关,而与黑肩绿盲蝽种群和褐飞虱卵的来源无关。 在高氮量稻株上黑肩绿盲蝽种群对褐飞虱卵的瞬时发现率(a)下降导致了功能反应的减弱, 而在相同含氮量稻株上黑肩绿盲蝽种群之间的捕食功能没有明显差异。黑肩绿盲蝽成虫取食水 稻伤流液和褐飞虱蜜露时寿命明显延长,取食高氮稻株的褐飞虱分泌的蜜露对延长黑肩绿盲蝽 雌成虫寿命的作用最大。但是,在高氮稻株上褐飞虱蜜露显著降低黑肩绿盲蝽的捕食能力。这 些结果表明黑肩绿盲蝽对褐飞虱自然控制作用的下降是稻田过量施用氮肥后褐飞虱种群增加的 主要原因之一。     

Effects of elevated CO2 and transgenic Bt rice on yeast‐like endosymbiote and its host brown planthopper

The effects of elevated CO₂ (750 vs. 375μl/l) on population abundances and metabolism enzyme of AChE and protective enzymes of SOD, POD and CAT in brown planthoppers (BPH) Nilaparvata lugens, and on size and abundances of yeast‐like endosymbiotes (YLES) were studied as BPH fed Bacillus thuringiensis (Bt) rice expressing pure Cry1Ab after successively two generations in open‐top chambers. The results indicated that: (1) Brachypterous and macropterous subpopulations and total population increased with elevated CO₂. Significant increases were found as BPH fed non‐transgenic rice while only significant increase as macropterous‐BPH fed Bt rice. (2) The responses of brachypterous and macropterous‐BPH to Bt rice were different. Brachypterous‐subpopulation significantly decreased (13.6%) while macropterous ones significantly increased (43.8%) as fed Bt rice relative to non‐transgenic rice at elevated CO₂. (3) Elevated CO₂ only significantly inhibited AChE activity as brachypterous‐BPH fed non‐transgenic rice. Significant increases in POD and SOD, and significant decrease in CAT were found as brachypterous‐BPH fed Bt rice, while significant increases in CAT and significant decrease in POD were also observed as fed non‐transgenic rice in elevated CO₂ relative to ambient CO₂. (4) Bt rice significantly inhibited POD and SOD activity at ambient CO₂, while only significantly enhanced SOD activity at elevated CO₂. (5) Elevated CO₂ significantly decreased YLES per mg/head of brachypterous‐BPH females while only significantly decreased YLES per mg/head as brachypterous‐BPH males fed Bt rice. And there were significant differences in YLES width or length between females and males. Elevated CO₂ can markedly affect the symbiosis relationship between YLES and BPH through the bottom‐up forcing on BPH physiological metabolism. And the damage inflicted by BPH on rice, irrespective of the presence of insecticidal genes, is predicted to be higher at elevated CO₂. Furthermore, transgenic Bt rice can also exacerbate emigrating‐macropterous‐BPH occurring especially at elevated CO₂.     

Genome‐wide analysis of Nilaparvata lugens nymphal responses to high‐density and low‐quality rice hosts

The brown planthopper (BPH) Nilaparvata lugens is an economically important pest on rice plants. In this study, the higher population density and yellow‐ripe stage of rice plants were used to construct adverse survival conditions (ASC) against BPH nymphs. Simultaneously, the low population density and tillering stage of rice plants were used to establish a suitable survival condition (SSC) as a control. Solexa/Illumina sequencing was used to identify genes of BPH nymphs responding to ASC. Significantly longer duration development of BPH nymphs and significantly lower brachypterous ratio of BPH adults were observed by ASC compared with SSC. A total of 2 544 differentially expressed genes (DEGs) were obtained and analyzed by BLASTx, Gene Ontology and KEGG Orthology. Gene ontology analysis revealed that the DEGs were mainly involved in categories of cell, cell part, cellular process, binding, catalytic, organelle and metabolic processes. 1 138 DEGs having enzyme commission numbers were assigned to different metabolic pathways. The largest clusters were neurodegenerative diseases (137, 12.0%), followed by carbohydrate metabolism (113, 9.9%), amino acid metabolism (94, 8.3%), nucleotide metabolism (76, 6.7%), energy metabolism (64, 5.6%), translation (60, 5.3%), lipid metabolism (58, 5.1%), and folding, sorting and degradation (52, 4.6%). Expressing profile of 11 DEGs during eight nymphal developmental stages of BPH were analyzed by quantitative real‐time polymerase chain reaction. The 11 genes exhibited differential expression between ASC and SSC during at least one developmental stage. The DEGs identified in this study provide molecular proof of how BPH reconfigures its gene expression profile to adapt to overcrowding and low‐quality hosts.     

THE VIRULENCE CHANGE AND DAMAGE CHARACTERISTICS OF VARIOUS GEOGRAPHIC POPULATIONS OF BROWN PLANTHOPPER*

Abstract The virulence change and damage characteristics of brown planthopper (BPH), Nilaparvata lugens Stal, populations collected from Guangxi, Yunnan and Zhejiang Provinces were studied by using various resistant rice varieties. The results indicated that the Zhejiang population could successfully infest varieties IR26 and Mudgo, showing the characters of BPH biotype 2 after 1989. The Guangxi population, however, could adapt the resistant varieties IR26, Mudgo and ASD7 after 1991. In 1997, the nymphal survival indices of Guangxi and Yunnan populations on Rathu Heenati (Bph3) were up to 70. 9 and 66. 7 respectively. This may imply that the BPH populations in Guangxi and Yunnan have shifted into a new biotype. In free-choice test, there was obvious difference in the feeding preference of nymphs and adults of Zhejiang population, the adult preferred to feeding on resistant variety IR26 and the nymphs chose the hosts randomly. Under 26 C and L12: D12, the nymphal duration of Zhejiang population was the longest in the three tested populations. For Guangxi population, the nymphal duration on ASD7 was significantly longer than on TN1, although it could infest resistant variety ASD7. The nymphal survival rate of Zhejiang population fed on IR26 was higher than those fed on TN1 and ASD7. On varieties IR26 and ASD7, an obviously higher nymphal survival rate was observed in Yunnan population as compared to those of Zhejiang and Guangxi populations. These results indicate that difference in virulence and damage characteristics could be found in different geographical populations of BPH.