小麦拟黄叶病症状和介体蚜虫传毒的初步研究

小麦拟黄叶病(WYLV)是黄淮流域近年小麦上发生的一种新病毒病。经传毒试验结果初步明确症状和传毒介体蚜虫种类。叶片初发病上半部退缘发白;后变为全叶退缘黄化,叶鞘顶端同时略变褐色。以多种介体蚜虫传播。以麦二叉蚜和禾谷缢蚜传毒力最强,麦长管蚜次之,而麦无网蚜和玉米叶蚜仅有时轻微传播。     

小麦中黄酮类化合物对麦长管蚜生长发育的影响

采用细SephadexLH-20葡聚糖凝胶柱从小麦叶片提取液中分离纯化得到两种黄酮类化合物，经核磁共振和紫外分光光度计吸收光谱等分析技术，鉴定出其结构为异荭草甙和异荭草甙-7-O-阿拉伯糖—葡萄糖苷。将不同浓度的两种黄酮类化合物加入麦长管蚜全纯人工饲料中饲养麦长管蚜，结果表明，分离得到的两种黄酮类化合物对麦长管蚜的生长、发育和繁殖均有明显的抑制作用。其中异荭草甙对该蚜有明显的抗生性，其抗性阈值浓度为0．02％左右。     

茉莉酸诱导小麦幼苗对麦蚜取食行为的影响

茉莉酸可诱导小麦品种郑州891的防御反应，使麦长管蚜Sitobion avenae(F.)和禾谷缢管蚜Rhopalosiphum padi(L.)的取食行为发生明显改变。尽管此两种蚜虫在正常的小麦相干株上取食的EPG各波型参数出现的次数及历时变化较大，但经茉莉酸诱导后，都再现了NP波次数和历时显著增加、E1与E2波历时明显缩短、首次出现E1波时间显著延长以及口针在细胞间穿刺频率明显升高等变化。这说明茉莉酸诱导后，郑州891的取食适合度降低，其机理与茉莉酸诱导产生挥发性的蚜虫取食拒避剂及诱导维管液营养成份的改变有关。试验还证实；麦长管蚜和禾谷缢管蚜的嗅觉和味觉感受器在其对寄主植物适合度的鉴别中共同起作用；植物适合度不能仅由1－2个EPG波形参数作为指示因子，要视具体情况全面分析，才能得出可靠的结论。     

麦田间作对麦长管蚜的生态调控作用

[目的]探讨麦田间作对麦长管蚜种群的生态调控作用。[方法]田间调查小麦单作田、小麦与绿豆、小麦与豌豆以8:2行距间作田麦长管蚜种群数量及其时间动态变化;室内利用"Y"型嗅觉仪测定麦长管蚜对小麦、小麦与绿豆、小麦与豌豆不同组合气味的选择性。[结果]麦田间作不能影响麦蚜种群随时间动态变化曲线,但能在一定程度上降低麦长管蚜无翅蚜和有翅蚜的数量。室内麦长管蚜无翅蚜和有翅蚜显著选择寄主植物的气味。当小麦与绿豆或小麦与豌豆组合时对麦长管蚜没有吸引作用。[结论]非寄主植物的气味对寄主植物气味起掩盖作用,干扰蚜虫的寄主定位,这可能是间作低于单作蚜量的原因之一。     

主要次生物质对麦蚜的抗性阈值及交互作用

用麦蚜全纯人工饲料加不同浓度次生物质的薄膜饲养技术,研究了8种次生物质对麦长管蚜(Sitobion avenae)及禾谷缢管蚜(Rhopalosiphum padi)生长、发育及若蚜增重等生命参数的影响和4种次生物质对麦长管蚜的复合作用。结果表明,除芸香苷外其余几种次生物质具不同程度的抗蚜性,统计分析得到不同次生物质抗蚜阈值。单宁与总酚对麦长管蚜有明显增效作用,单宁与门布存在一定的增效作用,总酚与丁布有一定的拮抗作用。单宁酸、总酚、香豆素和单宁酸、儿茶素、香豆素、门布分别是抗麦长管蚜和禾谷缢管蚜的次生物质。     

扫描电镜下的小麦叶毛性状与麦长管蚜生物学参数相关性分析

为明确小麦叶毛物理性状（密度和长度）与小麦抗蚜性的关系,在人工气候室内对麦长管蚜Sitobion avenae（F.）在11个小麦品种（材料）上的发育历期、成虫与幼虫的体重差、相对日均体重增长率、若蚜死亡率等生物学参数进行了测定,采用聚类分析法评价了其对麦长管蚜的抗性,利用扫描电镜技术研究了叶毛的超显微结构,并对叶毛密度和长度与蚜虫生物学参数间的相关性进行了分析。结果表明：亲本98-10-35、Amigo及杂交后代O31、L87最不适于麦长管蚜的生长,抗性最好;O63、A253、A33抗性次之;L71、1376、H23抗性较弱,H19对麦长管蚜的适应性最好,抗性最差。扫描电镜结果表明叶毛长度和发育历期呈极显著正相关,叶毛密度和相对日均体重增长率呈极显著负相关,说明叶毛长度和密度与小麦品种（材料）的抗蚜性显著相关。表明小麦物理性状是小麦抗蚜性的重要组成部分,可以作为抗虫育种的目标之一;抗感杂交小麦后代可遗传亲本的抗感特性。     

一种由麦二叉蚜、禾缢管蚜非专化性传毒的小麦黄矮病毒株系鉴定

 通过对河南省灵宝县采集的小麦黄矮病病株标样进行4种蚜虫传毒比较、薄膜饲毒、不同温度饲毒和接种试验、麦二叉蚜成、若蚜传毒比较及酶联免疫吸附试验等.证明这种标样的病毒只能由麦二叉蚜、禾缢管蚜非专化性传播,而麦长管蚜,玉米蚜不能传播.定为小麦黄矮病毒麦二叉蚜禾缢管蚜非专化性株系.     

小麦黄矮病优势介体麦二叉蚜传毒力测定

我国北方麦区发生流行的小麦黄矮病,借麦二叉蚜、麦长管蚜、麦无网蚜,禾谷缢蚜和玉米缢蚜持久性传播,其中麦二叉蚜为优势介体蚜虫种群,因此对麦二叉蚜、不同虫态及其龄期传播小麦黄矮病的能力进行了测定。     

一种由麦二叉蚜和麦长管蚜传播的小麦黄矮病毒株系的鉴定

 通过对采自我国内蒙古丰镇县13个春小麦病株标样进行4种蚜虫连续传毒比较,不同温度饲毒和接种试验,薄膜饲毒,2种蚜虫成若蚜传毒比较和血清学酶标试验等,明确我国内蒙古丰镇县小麦黄矮病毒株系为由麦二叉蚜和麦长管蚜有效传播的麦二叉蚜麦长管蚜株系(GAV)。对于这个株系,禾缢管蚜与玉米蚜是不能传播的。这种株系在我国冬麦区春麦区都有分布。     

蚜虫传播非持久性病毒的取食行为调控机制

蚜虫能够传播上百种植物病毒,是最重要的农业介体昆虫之一。蚜虫在刺探和取食植物过程中,唾液组分会连同附着在口针中的病毒粒子一同被分泌进入植物内,在调节植物诱导抗性、病毒侵染扩散、介体昆虫行为等过程中均有重要作用。本文围绕蚜虫传播病毒和获取病毒2个关键过程,总结分析了蚜虫独特的刺吸取食行为与传毒效率和获毒效率之间的联系;针对取食活动中关键的唾液蛋白在调控植物免疫抗性、帮助病毒侵染过程中的功能,阐述了蚜虫高效传播非持久病毒的分子基础;针对蚜虫的获毒过程,综述了病毒侵染植物间接调控蚜虫趋向和行为的作用方式。这些研究的开展将为解释蚜虫和病毒协同侵染的分子机制以及有效开展基于蚜虫取食行为调控的病虫害防控新技术提供思路。     

4种寄主植物的繁蚜－繁蜂能力和子代烟蚜茧蜂的寄生潜力比较

为比较不同寄主植物繁蚜,继而繁育烟蚜茧蜂Aphidius gifuensis的潜力,促进烟蚜茧蜂扩繁,从烟田采集供试烟蚜与烟蚜茧蜂,比较了烟草、萝卜、油菜和小白菜共4种常用寄主植物的繁蚜-繁蜂能力和繁育的子代烟蚜茧蜂的寄生潜力。结果显示:(1)烟草和萝卜的单株繁蚜速率较快、繁蚜量大,表明两者的繁蚜能力强于小白菜和油菜;(2)4种寄主植物上的僵蚜羽化率没有显著差异,烟蚜茧蜂对烟草和萝卜繁育烟蚜的寄生率显著高于小白菜和油菜,表明在烟草和萝卜上繁蜂能力强于油菜和小白菜;(3)烟草上繁育的子代蜂寿命及其后足胫节长度均显著大于在其他3种寄主植物上繁育的寄生蜂的相应参数,表明烟草上繁育的子代烟蚜茧蜂的营养状态优于在其他3种寄主植物上得到的烟蚜茧蜂。总体而言,烟草的繁蚜-繁蜂能力和子代烟蚜茧蜂的寄生潜力均强于其他3种寄主植物,更适用于烟蚜茧蜂扩繁;萝卜上繁育的子代烟蚜茧蜂的寄生潜力不及烟草,但明显优于小白菜和油菜,可作为一种烟蚜茧蜂繁育的替代寄主植物,用于提纯、复壮烟蚜和烟蚜茧蜂。     

寄主植物对棉蚜乙酰胆碱酯酶的影响

通过生物测定和生化分析研究了5种不同寄主植物上的棉蚜种群对灭多威的敏感性，乙酰胆碱酯酶（AChE)活性及灭多威对AChE的抑制作用，结果发现，取食石榴和花椒的棉蚜AChE活性最高，是冬青上棉蚜（最低）的2．00倍和3．33倍，说明寄主植物可以影响棉蚜AChE的活性，灭多威对不同寄主植物上的棉蚜个体的AChE进行抑制后，发现棉花和冬青上的棉蚜种群中AChE对灭多威不敏感的棉蚜个体多于花椒，木槿和石榴上的棉蚜种群，这与棉花及冬青上的棉蚜对灭多威耐药性较其它三种强的趋势近似，表明AChE敏感度的降低是棉蚜对灭多威产生抗药性的原因之一。     

The effects of <Emphasis Type="Italic">Gibberella zeae</Emphasis>, <Emphasis Type="Italic">Barley Yellow Dwarf Virus</Emphasis>, and co-infection on <Emphasis Type="Italic">Rhopalosiphum padi</Emphasis> olfactory preference and performance

Insect-borne viruses promote several changes in plant phenotype, which can modify plant-vector interactions in favor of virus survival and dissemination. Although co-infections commonly occur in the field, little is known about their effects on interactions with the vector. The ecological interactions between Barley Yellow Dwarf Virus (BYDV) and its aphid vector, Rhopalosiphum padi, have been investigated extensively, but the vector’s behavior in more complex scenarios has yet to be examined. We assessed olfactory response and performance of R. padi to wheat singly and doubly infected by the pathogenic fungus Giberella zeae and BYDV. Non-viruliferous aphids preferred odors of BYDV-infected wheat over healthy wheat, as previously reported in the literature, and they were still preferentially attracted to BYDV-infected plant during co-infection. However, around 35% more non-viruliferous aphids chose healthy wheat over G. zeae-infected wheat. Viruliferous aphids did not show any preference to the treatments. BYDV-infected wheat was a superior host than healthy wheat for the aphids whose population increased in 25%. We observed a synergistic effect of the co-infected wheat, which was the best host for aphids, and promoted an elevation of 42% on population growth. Our results indicate that co-infection might be beneficial for virus spread as does not interfere with aphid olfactory preference and provides greater colony growth than in singly infected plants.     

我国主要农作物蚜虫生物防治的研究进展、应用与展望

蚜虫是农业生产上的重大害虫,不仅通过取食韧皮部直接为害植物,还会传播很多植物病毒病,严重影响农作物产量和品质。目前防治蚜虫仍以化学农药为主,然而生物防治作为绿色环保、可持续的防治策略在这几十年中也得到了长足发展。该文对我国近60年关于主要农作物蚜虫生物防治的研究进展进行概述,包括主要农作物蚜虫的天敌资源（主要寄生性天敌196种,主要捕食性天敌16种,主要病原微生物6种）、蚜虫主要天敌生物学和生态学研究、人工扩繁及应用技术及植物抗蚜机制和抗蚜种质资源挖掘,并对目前蚜虫生物防治中存在的问题及未来的研究方向进行展望,以期为蚜虫生物防治技术的发展和推广应用提供参考。     

Glutenin and gliadin contents of flour derived from wheat infested with different aphid species

Aphid feeding in cereals results in both quantitative and qualitative yield losses; moreover aphid-transmitted viruses are responsible for other quantitative and qualitative damage so that direct or indirect effects of aphid infection are always of interest. At the beginning of stem elongation, wheat plants were caged regardless of the presence or absence of indigenous cereal aphids. Half of the caged plants were artificially infected with Diuraphis noxia. The number of D noxia and Rhopalosiphum padi individuals on plants destined for flour preparation was approximately 150 aphids per tiller at peak population. The number of Sitobion avenae individuals was ca 25 aphids per tiller. Bread-making quality of wheat flour is determined primarily by the protein content, the gluten proteins (gliadins, glutenins) being the prime factors. The absolute amounts and/or the relative proportion of gliadins and glutenins are very important in dough making and in determining baking quality. Flour from grains originating from plants infected naturally with cereal aphids indigenous to Hungary, and flour infected artificially with D noxia, were analysed for glutenin and gliadin content using size exclusion HPLC. It was found that aphid infection had a significant effect on the gliadin/glutenin ratio, which was significantly lower in wheat flour prepared from aphid-infected plants than in that from uninfected control. The most significant decrease in gliadin/glutenin ratio was caused by D noxia infection, followed by R padi and then S avenae. As the gliadin/glutenin ratio was significantly lower in flour made from aphid-infected wheat seeds, it can be supposed that aphid feeding results in decreased bread making quality of wheat flour.     

Transmission of barley yellow dwarf virus by cereal aphids collected from different habitats on cereal farms

Cereal aphids were collected from cereal crops, from Poa annua within cereal fields, from Lolium perenne pastures and from wild grasses in hedge bottoms and around farm buildings. The frequency of barley yellow dwarf virus (BYDV) transmission was assessed by aphid transmission tests. There were differences in transmission rates between aphid species, between host species and between years. The transmission rates of Rhopalosiphum padi from the different host species were broadly similar whereas for Sitobion avenae, P. annua within cereal fields was significantly better than the other host species. Wild grasses other than P. annua were relatively poor sources of virus. A large percentage of aphids frequently transmitted more than one strain, suggesting that host plants are often infected with more than one BYDV strain.     

Host plant preference of Diuraphis noxia (Kurdj.) (Hom., Aphididae)

Host plant preference of the Russian wheat aphid Diuraphis noxia (Kurdj.) was studied on 11 cultivars of 9 plant species: winter barley, spring barley, winter wheat, spring wheat, rye, oat, Triticale, canary grass, red millet yellow millet and maize. Seeds of the host plants were sown in a circle near the edge of pots. The host plant choice was evaluated 24 hours after releasing 55 Diuraphis noxia female adults in the middle of each pot. The suitability of different hosts for aphid development was evaluated 2, 7 and 14 days after infestation based on the mean number of Russian wheat aphid individuals per plant. Red millet, yellow millet and maize were chosen by significantly fewer aphids than grain crops. Winter and spring barley were chosen as hosts most frequently, and the progeny production was also the highest on these plants. The growth rate of D. noxia was significantly affected by the host plants and the date of assessment and their interaction.     

Transmissibility of Cucumber mosaic virus by Aphis gossypii Correlates with Viral Accumulation and Is Affected by the Presence of Its Satellite RNA

ABSTRACT Satellite RNAs (satRNAs) are associated with Cucumber mosaic virus (CMV) in tomato, most often causing severe epidemics of necrotic plants, and not associated with specific host symptoms. Laboratory studies on virus transmission by the aphid vector Aphis gossypii were performed to better understand the dynamics of field populations of CMV. The presence of satRNAs correlated with lower concentrations of virus in infected plants and with a decrease in the efficiency of transmission from satRNA-infected plants. Both the concentration of virus in CMV-infected tomato and the efficiency of transmission varied more extensively with nonnecrogenic satRNAs than with necrogenic satRNAs. A negative effect of satRNAs on virus accumulation can account, in part, for a decrease in the field transmission and recovery of CMV + satRNAs. Aphids behaved differently and probed less readily on plants infected with CMV + necrogenic satRNAs compared with plants containing non-necrogenic satRNAs. Aphid-mediated satRNA-free CMV infections were observed in test plants when aphids were fed on source plants containing CMV + nonnecrogenic satRNA; no comparable satRNA-free test plants occurred when aphids were fed on source plants containing necrogenic satRNAs. These results indicate that factors associated with transmission can be a determinant in the evolution of natural populations of CMV and its satRNA.