植物化感物质对种子萌发的影响及其生态学意义

化感现象作为植物之间的一种相互作用方式,在农林业生产中广泛存在。合理利用植物之间的化感作用,对于生产实践具有重要的指导意义。研究表明,化感物质可促进或抑制不同物种种子的萌发过程,这对于植物的生长发育、植物群落的组成与分布以及生态系统的平衡有着重要影响。本文从化感物质对种子萌发的影响与其生态学意义两个方面进行了综述。一方面,在阐述化感作用影响种子萌发的基础上,进一步总结了化感物质抑制植物种子萌发的生理生化机制。包括:化感物质通过抑制胚根和胚轴的伸长,破坏亚细胞结构,干扰植物激素及活性氧的合成与代谢,造成细胞损伤,从而阻碍种子萌发;抑制种子中储存物质的代谢,阻碍种子萌发过程中的物质以及能量转换,导致种子萌发受阻等。另一方面,本文从化感作用在抑制农田杂草及影响生态系统稳定性两个方面,阐述了化感物质调控种子萌发的生态学意义。讨论了农作物的化感抑草作用,农林业生产中的化感自毒作用以及化感作用造成的生物入侵等,以期为农林业生产提供借鉴。最后,根据目前研究进展,对本领域未来研究方向进行了展望和讨论。

Effect of plant allelochemicals on seed germination and its ecological significance

As a form of plant interaction, allelopathy plays a critical role in agriculture and forestry production, including biological invasion, continuous cropping obstacle and weed suppression. Consequently, it is important to guide production if we take advantage of plant allelopathy in crop production. Seed germination is a key stage of a plant and the regulatory mechanism of this physiological process by allelopathy has been paid more and more attention. Numerous studies demonstrated that allelochemicals could promote or inhibit seed germination of different plant species, which had an important influence on the plant growth and development, the composition and distribution of plant communities and the balance within the ecosystem. In this review, the effect of allelochemicals on seed germination and its ecological significance were summarized. On the one hand, the physiological and biochemical mechanisms underlying the inhibition effect of allelochemicals on seed germination were summarized. For example, allelochemicals restrained seed germination through inhibition of radicle and hypocotyl elongation. Allelochemicals also hindered seed germination by damaging subcellular structures, disturbed the synthesis and metabolism of both phytohormones and reactive oxygen species (ROS). Furthermore, allelochemicals delayed seed germination by mediating metabolism of protein, oil and starch, which provide energy during seed germination. On the other hand, we discussed the ecological significance of allelochemicals to seed germination from two perspectives, weeds control of farmland and ecosystem stabilization. Here, we summarized the effects of allelochemicals on weed suppression in natural settings, autotoxicity in agriculture and forestry, and biological invasion caused by allelopathy. Finally, based on current research progresses, future research directions in the field of allelopathy and autotoxicity were proposed and discussed.