蕨类植物的化感作用及其对生物多样性的影响

植物化感作用是植物通过向环境中释放化学物质从而对同种植株和繁殖体或与其他植物之间产生的直接或间接、有益或有害的作用，它影响植物分布、群落形成与演化、作物间作等，与生物多样性保护以及农林和园艺生产实践关系密切，在国际上受到越来越多的关注。但国内这方面的研究起步相对较晚，研究范围有限，对蕨类植物化感作用的报道更少。本文系统介绍了蕨类植物化感作用的研究进展，包括蕨类植物种内的化感作用(即自毒效应)、常见的蕨类植物种间的化感作用(即孢子体对配子体的化感作用和配子体对配子体的化感作用)及蕨类植物对种子植物的化感作用(蕨类植物可通过化感作用与种子植物争夺更多的资源和生长空间)。还介绍了种子植物对蕨类植物的化感作用(主要表现为抑制作用)以及蕨类植物化感作用与动物侵食、微生物侵染的关系，研究发现昆虫侵食能增强或减弱蕨类植物的化感作用，微生物的活动可能增强某些蕨类植物的化感作用。本文从上述不同角度说明蕨类植物化感作用对生物多样性的影响，希望有助于促进我国学者对该领域的深入研究。

Fern allelopathy and its impact on biodiversity

Allelopathy is a phenomenon of direct or indirect, beneficial or adverse effects of a plant on its own or another plant through the release of chemicals into the environment. It affects plant distribution, community formation, and intercrop evolution. It has a consanguineous relationship with biodiversity conservation, agriculture, forestry, and horticulture and is now arousing further international interest. In China, research on plant allelopathy began relatively late and thus has been limited, particularly studies of fern allelopathy. We introduce recent advances in fern allelopathy, including studies of autotoxicity of ferns, and of allelopathic interactions occuring in two ways: (1) sporophytes acting on gametophytes and (2) gametophytes acting on gametophytes. Fern autotoxicity is a type of intraspecific allelopathy, whereby a fern species inhibits the growth of its own kind through the release of toxic chemicals into the environment. Sporophytes acting on gametophytes and gametophytes acting on gametophytes are common phenomena of interspecific fern allelopathy. In addition, allelopathic effects between ferns and seed plants are discussed. Some ferns can compete with seed plants by fern allelopathy to obtain more resources and space, while some seed plants can inhibit the growth of ferns by allelopathy. Fern allelopathy also has relationships with consumption by animals and microbial infection. Insect herbivory can amplify or dampen the effects of fern allelopathy. Activity of microbes may amplify the allelopathic effects of some ferns. Impacts of fern allelopathy on biodiversity are discussed from the different perspectives described above.