几种白粉病菌的显微形态学分析

运用微分干涉显微镜分别观察了南瓜、凤仙花、黄瓜及番茄叶片上白粉病菌的显微形态,对侵染这几类植物的白粉病菌的分生孢子的形状、大小、分生孢子梗的形状以及孢子梗上着生分生孢子的数目等进行了比较,结果表明,它们的分生孢子的大小、分生孢子梗的形状及孢子梗上着生分生孢子的数目都有所不同,进而证明这些白粉病菌不是同一个物种。     

植物挥发物介导的种内与种间关系研究进展

植物通过释放的挥发性有机化合物(Volatile organic compounds,VOCs)介导其与周围环境中同种和不同种生物的相互作用,从吸引传粉、种子传播媒介,到保护自己免受植食性动物、病原菌和寄生生物的侵害等。植物挥发物尤其是虫害诱导挥发物是近30年来化学生态学和植物保护领域的研究热点。本文综述了近年来植物挥发物介导的种内与种间关系的研究进展,主要概括了植物挥发物的基本特征,植物挥发物在调控植物种内及种间、植物与昆虫、植物–害虫–天敌三营养级关系、以及植物与微生物互作中的生态学功能,并对其在农业生产中的应用和前景进行分析,总结这一领域尚未解决和亟需深入研究的问题,为植物挥发物应用于有害生物的控制提供理论依据。     

哥德恩蚜小蜂对6种不同植物及其挥发物的选择行为

【目的】揭示哥德恩蚜小蜂(EncarsiaguadeloupaeViggiani)对螺旋粉虱(Alerodicusdispersus Russell)不同寄主植物及其挥发物的选择行为,为人工扩繁哥德恩蚜小蜂的最适寄主植物选择提供参考。【方法】采用寄生选择试验和Y型嗅觉仪观测哥德恩蚜小蜂对6种螺旋粉虱寄主植物(番石榴、一品红、木薯、番木瓜、番茄、辣椒)的趋性差异。【结果】哥德恩蚜小蜂对6种不同供试植物上螺旋粉虱的寄生率从高到低依次为:番石榴>一品红>辣椒>番木瓜>木薯>番茄;Y型嗅觉仪测定结果表明,哥德恩蚜小蜂对一品红的趋性最强,其次为番石榴,对木薯、番茄趋性较弱。【结论】一品红和番石榴均是哥德恩蚜小蜂选择率较高的植物,理论上可将其作为寄主植物繁殖饲养哥德恩蚜小蜂。     

Attraction of bruchid beetles Callosobruchus chinensis (L.) (Coleoptera: Bruchidae) to host plant volatiles

Host-plant volatiles play an important role as cues for herbivores in search of resources, mates and oviposition sites in complex environments. Plant volatile-based attractants can be developed for pest monitoring and control. Previously, we indicated that mated female adults of Callosobruchus chinensis showed choice preference behavior toward 2-hexenal and benzaldehyde. Our objective here was to investigate the synergistic effect of host-derived attractive volatiles in attracting C. chinensis under laboratory and field conditions in Shanxi Province, China. We hypothesized that the ratio and concentration of volatiles derived from Vigna radiata play critical roles for C. chinensis in locating this host. Therefore, we collected and identified the volatiles of mungbean by using headspace collection and GC-MS. The effectiveness of different ratios and concentrations of two compounds (2-hexenal and benzaldehyde) that elicit C. chinensis searching behavior were examined in Y-tube olfactometer assays. The combination of 300 μg μL⁻¹ 2-hexenal and 180 μg μL⁻¹ benzaldehyde loadings exhibited a synergistic effect on attracting C. chinensis (82.35%). Compared to control traps, the adults were significantly attracted to traps baited with blends, and more attraction to females than males was found for blend traps in the field experiments. Our results suggest that blends of this specific concentration and ratio of benzaldehyde and 2-hexenal can be used in traps as attractants for C. chinensis monitoring and control in the field.     

Increased resistance of drought by Trichoderma harzianum fungal treatment correlates with increased secondary metabolites and proline content

Plant secondary metabolites play vital role in plant stress response. In this study we investigated whether root colonization of tomato(Solanum lycopersicum) infected by Trichoderma harzianum leads to alterations in the biosynthesis of secondary plant metabolites including phytohormones and osmolyte proline under drought stress. Exposure of tomato to drought caused a drastic decline in plant growth and physiological parameters. Tomato inoculated with T. harzianum showed increased root and shoot growth and chlorophyll pigments as compared to uninoculated controls as well as drought stressed plants. Proline and total soluble protein content was increased in plants inoculated with T. harzianum under both normal as well as drought conditions. An obvious increase in phenol and flavonoid content was observed due to T. harzianum. In addition, T. harzianum inoculated plants maintained higher levels of growth regulators indole acetic acid, indole butyric acid, and gibberellic acid under drought stress. Improved secondary metabolites which play an important role in plant stress tolerance by T. harzianum may have coordinately worked for bringing the growth regulation by protecting membranes from reactive oxygen species(ROS) and enhance plant growth through accessing more nutrients by root system.     

光肩星天牛成虫对原寄主枝条挥发物趋向的测定

光肩星天牛是一种食性很广的蛀干害虫。利用Y型嗅觉仪测定了从漳河柳、箭杆杨、合作杨和新疆杨4种不同抗性等级树种上羽化的光肩星天牛成虫对这4种寄主树种和嗜好树种复叶槭枝条气味的嗅觉反应。在以空气为对照试验中,源自4种不同寄主树种上的光肩星天牛成虫对其原寄主树种枝条挥发性气味均有明显的正趋性反应（P0.05）。但从合作杨、漳河柳和箭杆杨上羽化的光肩星天牛成虫对新疆杨枝条挥发性气味表现出不同程度的忌避作用;复叶槭枝条挥发性气味对源自4种寄主树上的光肩星天牛均具有不同程度的引诱作用,并且对源自箭杆杨、合作杨和新疆杨上的雌性成虫的引诱作用达到了差异显著的程度（P0.05）。在以复叶槭气味为对照试验中,4种不同寄主上羽化的光肩星天牛对原寄主气味和复叶槭气味的趋向差异不大。这表明在没有嗜好寄主气味的前提下光肩星天牛可以识别原来寄主气味,但是如果有嗜好树种气味存在,光肩星天牛就不趋向原来寄主树种的气味。      

寄生植物菟丝子防治入侵种紫茎泽兰研究初探

利用寄生植物菟丝子防治外来杂草紫茎泽兰,研究菟丝子寄生紫茎泽兰与对照紫茎泽兰的株高和叶片数的变化。结果表明：菟丝子寄生紫茎泽兰后对其株高有一定的影响,但对叶片影响不大,说明菟丝子能在一定程度上控制紫茎泽兰的生长。     

虫害诱导植物挥发物的释放机制及应用

虫害诱导的植物挥发物(HIVs)是植物受到害虫为害时产生和释放的,并且是植物进行通讯和保护自身的挥发性物质.HIVs能调节植物、植食性昆虫和天敌之间的关系,对昆虫的行为调控有非常重要的作用,近年来已引起人们的广泛关注.从HIVs的释放机制和应用两方面进行综述,有助于开发和利用HIVs保护植物,降低植食性害虫的危害水平,实施保护植物的新策略.     

挥发性化合物介导的植物-植食性昆虫-天敌三级营养级互作机制及应用

农业生态系统中植物-植食性昆虫-天敌三级营养级间存在复杂的互作关系,挥发性化合物在三级营养级互作中发挥着重要作用。植食性昆虫能够以植物挥发物为化学线索精准地识别和定位寄主,而虫害诱导的挥发物作为关键的化学信息物质对于调控三级营养级关系起到不可或缺的作用,一直是该领域研究的重点和热点问题。另外,植物为传粉昆虫提供花粉或者花蜜,传粉昆虫可以通过识别花中挥发物寻找食物来源,在帮助植物传粉的同时有利于自身的生长发育与繁殖。近40年来,随着传统化学生态学研究的不断深入,特别是化学分析手段和灵敏度的不断提高以及电生理研究技术的广泛渗入,新的研究理念、研究手段快速形成与发展。在三级营养级互作的过程中,昆虫化学感受基因参与了对挥发性化合物的识别。因此,对昆虫化学感受基因的挖掘与功能鉴定将有助于解析昆虫化学感受的分子机制,研发更高效的昆虫行为调控产品并科学合理地应用于农业害虫的绿色防控,对于农田生态环境的保护具有十分重要的意义。本文综述了挥发性化合物对植食性昆虫、天敌昆虫与传粉昆虫行为的影响,详述了挥发物介导的三级营养级之间的互作机制与研究现状,以及在害虫绿色防控中的应用,并对未来重点研究的问题进行了展望。     

宁夏植物病原细菌、线虫及寄生性种子植物种类调查

记述了笔者1985年至今对宁夏植物病原细菌、线虫和寄生性种子植物种类的调查结果。共发现病原细菌6属17种,病原线虫4属6种,菟丝子4种,锁阳1种,列当2属6种。它们可引起近百种植物病害。文中附有病原物和寄主植物中名、拉丁学名及病害的分布和危害情况。对各类寄生性种子植物的两重性经济价值进行了讨论。     

桑白蚧的研究进展

桑白蚧Pseudaulacaspis pentagona(Targioni-Tozzetti) 是广泛分布于热带、亚热带和温带地区的一种寄主范围广、食性杂、繁殖力强的重要昆虫.目前发现其为害的寄主植物已达55个科,120个属.随着花卉和其它植物苗木的调运使得桑白蚧在世界各地广泛传播与蔓延,其危害已成为全球性的严重问题.近年来在我国南北方对果树、庭园花卉和经济林木等造成危害,尤其以桑、桃、李、杏等核果类果危害日趋严重.就桑白蚧的起源分布、发生危害、防治技术的应用等方面的研究进展进行综述.     

Defensive function of herbivore-induced plant volatile emissions in nature

Herbivore attack is known to increase the emission of volatiles, which attract predators to herbivore-damaged plants in the laboratory and agricultural systems. We quantified volatile emissions from Nicotiana attenuata plants growing in natural populations during attack by three species of leaf-feeding herbivores and mimicked the release of five commonly emitted volatiles individually. Three compounds (cis-3-hexen-1-ol, linalool, and cis-alpha-bergamotene) increased egg predation rates by a generalist predator; linalool and the complete blend decreased lepidopteran oviposition rates. As a consequence, a plant could reduce the number of herbivores by more than 90% by releasing volatiles. These results confirm that indirect defenses can operate in nature.     

5种外来入侵植物对小麦的化感作用

为洛阳地区麦田中恶性杂草的防除提供参考依据,采用培养皿滤纸法培育小麦幼苗,测定苦苣菜、续断菊、小马泡、曼陀罗和阿拉伯婆婆纳5种入侵植物对小麦种子发芽率、幼苗苗高及根长生长的化感作用。结果表明:随茎叶水浸提液浓度的增加,苦苣菜、续断菊、小马泡和阿拉伯婆婆纳4种入侵植物对小麦种子萌发的抑制作用逐渐增大,而曼陀罗浸提液浓度达0.2g/mL时才表现出明显的抑制作用;5种入侵植物茎叶水浸提液对小麦苗高具有低促高抑的化感作用,而根长除受苦苣菜的化感抑制作用外,同样受其他入侵植物低促高抑的化感作用,不同的是其抑制起始浓度总体小于苗高,而相同浓度处理下的抑制作用(RI绝对值)略大于苗高。综合效应平均值显示,5种入侵植物茎叶水浸提液对小麦的化感抑制作用依次为苦苣菜曼陀罗小马泡续断菊阿拉伯婆婆纳。     

植物挥发性化合物在小蠹虫寄主选择中的作用

植物挥发性化合物在小蠹类森林害虫对寄主树木的选择过程中发挥着重要的作用.本文综述了小蠹类森林害虫入侵危害过程中起关键作用的植物挥发性化合物的种类、生物活性和小蠹虫触角化学感受器的结构、功能等最新研究进展,并讨论了植物挥发性化合物在小蠹虫行为与可持续控制中的应用前景.     

NMF菌群腐熟牛粪对植物病害及土壤微生物的影响

采用盆栽试验研究了NMF菌群腐熟牛粪对植物病害以及土壤微生物的影响。结果表明,NMF菌群腐熟牛粪能明显降低小麦纹枯病和番茄灰霉病的发病率,对水稻恶苗病的抑制效果不明显。另外,腐熟牛粪可以促进土壤中细菌和放线菌的生长,抑制土壤中真菌的生长。     

滴灌对温室新几内亚凤仙生长的影响

本文利用正交试验方法,研究了滴灌灌水量和灌水周期对温室新几内亚凤仙生长的影响,初步得出了温室中新几内亚凤仙生长的最佳灌水量和灌水周期．试验表明,灌水量和灌水周期以及它们的交互作用对新几内亚凤仙生长的影响主次和程度,因新几内亚凤仙生长阶段的不同而不同,因此灌水量和灌水周期应根据生长阶段和生产实际情况的不同分别确定．     

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.     

Over-expression of GhDWF4 gene improved tomato fruit quality and accelerated fruit ripening

Brassinosteroids(BRs), a class of steroidal phytohormones are essential for many biological processes in plant. However, little is known about their roles in fruit development. Tomato is a highly valuable vegetable and has been adopted as the model species for studying fruit growth, development, and ripening. To understand the role of endogenous BRs in the development of tomato fruit, the expression patterns of three homologues of DWF4 gene were investigated and the transgenic tomato plants were generated in which the Gh DWF4 gene from upland cotton(Gossypium hirsutum L.) was ectopically expressed. The contents of main quality components were analyzed in fruits of transgenic tomato line and non-transgenic line(control plant, CP) when the fruit was mature. Sl CYP90B3 that possesses high homology with Gh DWF4 preferentially expressed in mature fruit. Significantly higher contents of soluble sugar, soluble proteins, and vitamin C were obtained in fruit of transgenic tomato lines compared with those in the CP. Furthermore, overexpressing Gh DWF4 promoted fruit growth and ripening. The weight per fruit was increased by about 23% in transgenic lines. In addition, overexpressing Gh DWF4 promoted the germination of transgenic tomato seeds and hypocotyl elongation of seedlings. These results indicated that overexpressing Gh DWF4 gene in tomato could increase the contents of many nutrients in fruit and accelerate fruit ripening. It is suggested that increased endogenous BRs in fruit affect the growth and development of tomato fruit and therefore improved the nutrient quality of tomato.     

我国北方11省（区）、直辖市小麦白粉病菌寄主范围研究

 对采自我国北方11个省（区）、直辖市的65个市、县，小麦近缘野生植物8属42种393份，用小麦白粉病菌11个小种的混合菌种进行接种，除21份免疫外，均接种成功。用接种成功的7属40种共286份小麦近缘植物产生的白粉病菌，分别对小麦回接，亦全部回接成功。用6个小麦白粉病菌小种，对7属15种共29份小麦近缘植物进行分小种接种，发现它们与在小麦上一样有很强的寄生专化现象。在1～6叶期，84.4%的小麦近缘植物对小麦白粉病菌的感病性随生育期的推移而下降，其中47.4%病情降为0,37.0%部分病情下降，15.6%病情变化不大。     

植物矮化基因相关研究进展

植物株型的矮化调控是遗传育种的一项热门研究。国内外学者对植物矮化机理、矮化基因、矮化遗传育种等均进行了较深入的研究,水稻、玉米、小麦等粮食作物和黄瓜、番茄、南瓜等园艺作物均已形成了较完善的矮化研究体系。矮化植株株型紧凑、冠幅小,能够有效提高抗倒伏能力,在生产实践中具有管理便利的优点,因此矮化育种是植物育种的发展趋势。激素调控是目前运用较为广泛的矮化调控手段,植物激素通过影响细胞的分裂和伸长来改变节间长度和数目,从而调节高度,达到矮化植株的效果,常用激素有赤霉素、油菜素内酯、生长素、乙烯等,这些激素促进或抑制植物的生长发育,与矮化突变体的形成有关,且各种激素信号通路之间存在相互作用。综述了禾本科、茄科、葫芦科等植物矮化基因的研究现状,激素调控下矮化突变体的形成,矮化基因的克隆及功能研究进展,探讨了植物矮生性状分子机理和分子遗传学研究进展,为后续研究植物矮化基因提供理论基础。