Abstract: The inhibitory effect of allelochemicals released by submerged macrophytes on ph ytoplankton is considered as one of the mechanisms that contribute to the stabil ization of clear-water status in shallow lakes. This paper reviewed t he research progress in the allelopathy of submerged macrophytes on algae from t he aspects of the occurrence frequency and coverage of allelopathically active s ubmerged macrophytes in lakes, and the kinds and allelopathical effects of the a llelochemicals released from the macrophytes. The previous researches indicated that allelopathically active submerged macrophyte species such as Myriophyllum , Ceratophyllum, and Elodea were efficient to control phytoplankton, espec ially when their biomass was high enough, and the dominant algae were sensitive species. The allelochemicals such as hydroxybenzene released by the submerged ma crophytes could inhibit the growth of algae. Different phytoplankton species exh ibited different sensitivity against allelochemicals, e.g., cyanobacteria and di atom were more sensitive than green algae, while epiphytic species were less sen sitive than phytoplankton. Environmental factors such as light, temperature, and nutrients could significantly affect the allelopathical effect of submerged mac rophytes. The research of the allelopathy of submerged macrophytes is still at i ts beginning, and further researches are needed on the effects of environmental factors on the allelopathy, extraction and identification of allelochemicals, se lective algal control mechanisms, and metabolism of the allelochmicals.

Key words: Pinus densiflora var. zhangwuensis, Pinus sylvestris var. mongolica, salt-alkali stress, physiological indices.