不同状态浒苔对东海原甲藻生长的影响

近年来富营养化等海洋污染现象日益加重,我国近海每年都会暴发浒苔绿潮和微藻赤潮现象。本文在实验室模拟条件下,研究了不同状态不同含量的浒苔(Ulva prolifera),即浒苔新鲜藻体、浒苔培养液和浒苔干粉末与东海原甲藻(Prorocentrum donghaiense)共培养时产生的竞争抑制作用。结果表明,浒苔新鲜藻体、浒苔培养液和浒苔干粉末在初始质量含量大于1 g/L的条件下都会对东海原甲藻产生抑制作用,浒苔干粉末的抑制强度远远超过浒苔培养滤液和浒苔新鲜藻体。在二者共培养时,出现了"低促高抑"的现象,即浒苔含量较低时会促进东海原甲藻的生长,而高含量的浒苔则抑制东海原甲藻的生长,且抑制作用随浒苔含量的升高而增大。浒苔对东海原甲藻的这种抑制作用,一方面可能来自于营养物质的竞争和消耗,另一方面可能来自于浒苔释放的化感物质对东海原甲藻产生的影响。利用浒苔对东海原甲藻的抑制作用,可为东海原甲藻赤潮的生物防治提供一种思路与方法。

Effects of Ulva prolifera in different states on the growth of Prorocentrum donghaiense

In recent years, green tide of Ulva prolifera and red tide of microalgae occurred frequently with increasing marine pollution such as eutrophication in Chinese coastal waters. In this paper, the competitive inhibitory effects of U. prolifera fresh algae, U. prolifera culture filtrate and U. prolifera dry powder in different contents on Prorocentrum donghaiense were studied under laboratory simulation conditions. U. prolifera fresh algae, U. prolifera culture filtrate and U. prolifera dry powder all had inhibitory effects on P. donghaiense under the condition that the initial mass content was greater than 1 g/L, and the inhibitory intensity of U. prolifera dry powder was much higher than U. prolifera culture filtrate and U. prolifera fresh algae. In the co-culture groups, the phenomenon of “low promotion and high inhibition” appeared. Low content of U. prolifera promoted the growth of P. donghaiense, and high content of U. prolifera inhibited the growth of P. donghaiense. In addition, the inhibitory effects increased with the increasing content of U. prolifera. This inhibitory effects of U. prolifera on P. donghaiense may come from the competition and consumption of nutrients. In addition, the effects may also come from the influence of allelopathic substances released by U. prolifera on P. donghaiense. The inhibitory effects of U. prolifera on P. donghaiense can provide ideas and methods for the biological control of red tide.