植物-植食性昆虫-天敌三营养层次的相互作用及其研究方法

根据国内外的最新研究成果 ,从他感化合物和植物的营养物质、有毒物质、形态特征、密度、多样性以及分布等化学和物理因子两方面阐述了植物、植食性昆虫及其天敌三营养层次间直接和间接的相互关系 ,揭示了植物在三者关系中的核心作用 ,并就目前在该领域中的一些常用的研究方法作了介绍 .

植物的诱导抗虫性

Changes in ontogeny, morphological character, physiological state, nutritional quality and secondary chemicals of plant could be induced by prior damage. The induced changes might have general negative effects on the behavior, development, survival and fecundity of successively occurred phytophagous insects because a change will redUce plant nutritional value, stimulate plant to produce poisonous chemicals or release synomone attractive to their natural enemies. Induced plant resistance could be an on-off response, be turned on in a relative short time when plants are damaged to above a certain threshold and causes plant show an individual and population effect on phytophagous insects due to its transmission within a plant and between plants. Induced plant resistance is variable among plant species, varieties, individuals and developmental stages and could be influenced by plant density, damage position and level, soil fertility and water content. Two aspects in thisarea, the mechanism of plant causing induced resistance and its relative importance on controlling phytophagous insects, should be studied further for convincing conclusions in the future.

植物与植食性昆虫的分子互作:基础与应用

植物与植食性昆虫之间存在着复杂的分子互作。首先,植食性昆虫会利用自身的嗅觉和味觉化学感觉系统,通过对植物挥发性和非挥发性信息化合物的编码与解析,结合对植物颜色、形状等物理信息的感觉与编码,定位及确定寄主植物。其次,植物可以通过位于细胞膜的受体识别植食性昆虫相关模式分子和损伤相关模式分子,启动由早期信号事件和植物激素信号途径介导的防御反应,并由此而影响植食性昆虫的种群适合度。最后,为抵御寄主植物的防御反应,植食性昆虫会通过复杂多样的反防御策略适应或抑制寄主植物的防御反应。本文对如上所述的植物与植食性昆虫分子互作研究进展及由此而开发的一些害虫防控新技术进行了综述。

昆虫化学生态学研究进展及未来展望

昆虫化学生态学是化学生态学的重要组成部分,在理论和应用上都有重要意义,是植物保护的重要理论基础。国际昆虫化学生态学经历了4个发展阶段,随着分子生物学和生物技术的应用,化学生态学已经进入分子时代。我国昆虫化学生态学在昆虫化学感受机理、昆虫信息素的鉴定和利用、植物信息化学物质对昆虫行为的调控机理和利用、植物与昆虫互作化合物的开发利用等理论和应用研究方面取得了很大成就,但从系统性、深入性和延续性来说,与国际水平尚有一定差距。本文在综述国内外昆虫化学生态学进展的基础上,提出了我国昆虫化学生态学研究的几个发展方向及措施。

化学信息素在植物—植食性昆虫(螨类)—天敌相互关系中的作用

植物、植食性昆虫 (螨类、天敌间通过各种物理因素和化学因素相互作用。近年来 ,随着化学生态学的发展 ,人们发现化学信息素在三者间的相互关系中起着非常重要的作用。本文对不同来源 (植物、植食性昆虫 (螨类 ) )

Evaluation of bias on the assessment of diet breadth of herbivorous insects using molecular methods

The interactions between herbivores and their host plants play a key role in ecological processes. Understanding the width and nature of these interactions is funda- mental to ecology and conservation. Recent research on DNA-based inference of trophic associations suggests that the host range of phytophagous insects in the tropics may be wider than previously thought based on traditional observation. However, the reliability of molecular inference of ecological associations, still strongly dependent on PCR and thus exposed to the risk of contamination with environmental DNA, is under debate. Here, we explored alternative procedures to reduce the chance of amplification of external, nondiet DNA, including surface decontamination and analysis of mid/hind guts, comparing the results with those obtained using the standard protocol. We studied 261 specimens in eight species of Neotropical Chrysomelidae that yielded 316 psbA-trnH intergenic spacer sequences （cpDNA marker of putative diets） from unique and multiple-band PCR results. The taxonomic identity of these sequences was inferred using the automated pipeline BAGpipe, yielding results consistent with 31 plant families. Regardless of the proto- col used, a wide taxonomic spectrum of food was inferred for all chrysomelid species. Canonical Correspondence Analysis using these data revealed significant differences at- tributed mainly to species （expectedly, since they represent different ecologies）, but also to treatment （untreated vs. cleaned/gut samples） and PCR results （single vs. multiple bands）. Molecular identification of diets is not straightforward and, regardless of the species＇ niche breadth, combining approaches that reduce external contamination and studying multiple individuals per species may help increasing confidence in results.

sRNA移动在植物与植食性昆虫互作中的作用

植食性昆虫与植物间存在多种互作,涉及到基因表达、代谢组学变化和植物激素串扰等多个方面。小RNA(small RNA,sRNA)作为一种植食性昆虫与植物间的调节因子可在基因转录或转录后起作用,主要表现为控制染色体的剪接和翻译,诱导信使RNA(messenger RNA,mRNA)抑制和指导靶转录本降解等。因此,sRNA介导的基因调控是植食性昆虫与植物互作研究中的重要内容。其中,外源sRNA在植食性昆虫和植物细胞间、细胞外以及生物体间的信号分子作用备受关注,且基于sRNA的生物防治技术研究也逐渐被应用于实践。该文主要对s RNA在植食性昆虫和植物间的迁移方式及sRNA在植食性昆虫和植物生长发育过程中产生的影响进行综述,探讨sRNA对植物-寄生体-植食性昆虫体系的影响,并对sRNA在农业重大虫害生物防治领域的应用前景进行展望,以期开发绿色高效的生物防治药剂,减少化学农药用量,创造更高的经济价值和环保价值。

植物与植食性昆虫化学互作研究进展

植物与植食性昆虫之间存在着复杂的化学相互作用。一方面,当遭受植食性昆虫为害时,植物能识别植食性昆虫相关分子模式,触发早期信号事件和激素信号转导途径,并由此引起转录组与代谢组重组、直接和间接防御化合物含量升高,最后提高对植食性昆虫的抗性。另一方面,植食性昆虫也能识别植物的防御反应,并能通过分泌效应子、选贮、解毒以及降低敏感性等反防御措施抑制或适应植物的化学防御。深入剖析植物与植食性昆虫的化学互作,不仅可在理论上丰富对昆虫与植物互作关系的理解,而且可在实践上为作物害虫防控新技术的开发提供重要的理论与技术指导。