植物的抗螨机理

The resistant mechanisms of plants to mites

植食性螨类分布广泛,危害多种寄主植物。本文从3个方面介绍了植物的抗螨机理:植物形态如叶型、叶色主要影响螨类的取食产卵位点和营养物质的获取;植物组织结构如叶厚、蜡质、茸毛、气孔等决定螨能否顺利利用口针取食到植物的汁液,而虫菌穴则作用于捕食螨和植食性螨的相互关系,从而达到保护植物的目的;植物理化性质如叶鲜重、生长速度、生育期反映了植物受害后的恢复能力,植物营养成分如水分、氮、可溶性糖、淀粉、叶绿素、氨基酸等的含量会直接影响螨的取食、生长发育和繁殖等,而植物的次生代谢物质,如酚类化合物、单宁、香豆素、类黄酮、生物碱等,则发挥着更加重要的抗螨作用。文章讨论了转Bt基因植物对植食性螨及其天敌的影响,短期内其对植食性螨没有显著的影响,但是螨在Bt植物上有逐渐加深危害的趋势。

Phytophagous mites are widely distributed and cause damage to various host plants.Three aspects of plant resistance mechanisms are discussed：1.Plant morphology,such as leaf shape and leaf color,mainly affects the feeding and oviposition sites of mites and obtainable nutrients.2.Tissue structures,such as leaf thickness,waxiness,leaf trichomes and stomata,may influence the ease of stylet penetrations and leaf domatia play an important role in the relationship between predatory mites and phytophagous mites.3.Physical and chemical properties,such as leaf weight,growth rate and development stages,reflect recovery of plants from damage.The availability of water,carbon and nitrogen used for the production of soluble sugars,starch and amino acids,directly affects the feeding,growth and reproduction of mites.More critical and more influential are plant secondary metabolites,such as phenolic compounds,tannins,coumarins,flavonoids and alkaloids,amongst others.In addition,the effects of Bt-modified plants on phytophagous mites and natural enemies are discussed;the addition of the transgene does not have an obvious impact on phytophagous mites in short term,but mites on Bt-modified plants display a gradual increase in adverse demographic trends.