中文摘要：

以Lemna aequinoctialis LC33,Landoltia punctata LC06和Spirodela polyrhiza LC15作为供试材料,在不同环境条件（温度、光照、营养）下对其进行单独和混合培养,研究生长条件和物种多样性对可溶性糖含量和生物量的影响。结果表明,低温（20℃）、强光照（10 000 lx）、低营养（N为0 mg/L,P为0 mg/L）的条件更有利于浮萍可溶性糖的积累。此外,适当的混养有助于浮萍可溶性糖的积累,如由3种浮萍组成的混养体系在低温条件下可溶性糖含量较高;由两种或3种浮萍组成的混养体系在强光照条件下可溶性糖含量较高;由两种浮萍组成的混养体系在低营养条件下可溶性糖含量较高。由此可见,生长条件和物种多样性与可溶性糖含量密切相关,适当的混合培养可以提高整个体系的生物质产量。

英文摘要：

To explore the effects of growth conditions and duckweed species diversity on duckweed growth and soluble sugar productivity, three strains（Lemna aequinoctialis LC33, Landoltia punctata LC06 and Spirodela polyrhiza LC15） were employed to culture either in polyculture or in monocultures under different conditions（temperature, light intensity, nutrient concentration）.Results showed that the duckweed accumulated more soluble content and biomass under the low temperature（20 ℃）, high light intensity（10 000 lx） and lower nutrient concentration（0 mg N/L, 0mg P/L）. Overall, several duckweed polyculture had higher soluble sugar content than those in monoculture. Specifically, the soluble sugar content of the poluculture composed of three strains was the highest when the temperature was low; the soluble sugar content of the polycultures composed of two or three strains was higher than those in monoculture when the light intensity was high; the polyculture composed of two strains accumulated more soluble content under the low nutrient concentration. Therefore, the growth conditions and species diversity had a great influence on soluble sugar content of duckweed. The appropriate polyculture is helpful for improving the biomass production of the whole duckweed cultivation system.