根分泌的化感物质及其对土壤生物产生的影响

ALLELOCHEMICALS FROM ROOT EXUDATES AND THEIR EFFECTS ON SOIL BIOTA

植物根系分泌物包含多种功能次生物质,其中化感物质是具有重要生理生化功能的一类物质,这些化感物质释放到根际,能够对土壤生物产生影响。现已发现,根系是化感物质进入环境的重要通道。因此,研究根分泌的化感物质具有重要的理论和实践意义。总结了根分泌化感物质的种类及其化感效应,论述了化感物质在土壤中的迁移、转化及影响因素,分析了生物和非生物因素与根系分泌化感物质之间的关系。此外,根系分泌化感物质的研究手段对于所取得的研究结果至关重要,其中根分泌物收集系统(CRETS)是收集根分泌化感物质的常用而且可行的方法之一。对于根分泌化感物质的分离鉴定技术有多种,可根据需要选择适宜的分离方法。还重点列举了一些作物根分泌的化感物质对土壤生物产生的直接和间接影响,阐明了根分泌的化感物质在土壤中所起的重要化感作用。根分泌物化感作用的研究已成为土壤生态学领域的热点与前沿课题,自然条件下原位收集鉴定植物根系分泌物中的化感物质等诸多问题是该领域今后的研究重点。

Allelochemicals are the predominant constituents identified from root exudates, which have physiological and biochemical functions and take effect on soil biota. Root system is the important passage for allelochemicals release into environment, and hence, researches on the allelochemicals excreted from it are of academic and practical significance. This paper summarized the varieties of allelochemicals from crop root exudates and their allelopathic effects, highlighted their transportation, transformation and affecting factors, and analyzed their relationships with biotic and abiotic factors. This review also described the methodologies in studying allelochemicals from root exudates. There are many chemical methods used for the separation and identification of allelochemicals. One of the common used techniques for collecting root exudates in large amount is CRETS (continual root exudates trapping system). From the standpoint of soil ecology, the direct effects of allelochemicals from crop root exudates on soil biota (bacteria, fungi, nematode etc.) were specifically discussed, and the key function of allelochemicals from root exudates in soil was presented. As allelochemicals from plant root exudates are becoming a hotspot in the field of soil ecology, such problems as the nondestructive techniques for collecting in-situ and the identification of allelochemicals from plant root exudates should be emphasized in the future.