1Environmental and Analytical Laboratories, Faculty of Science, E H Graham Centre for Agricultural Innovation (Industry & Investment NSW and Charles Sturt University), Charles Sturt University, Wagga Wagga, NSW- 2678, Australia
Research Centre of Hydrobiology, Key Laboratory of Aquatic Eutrophication and Control of Harmful Algal Blooms of Guangdong Higher Education Institutes, Jinan University, Guangzhou510632, Guangdong, China
*Correspondence author: E-Mail: tssduan@jnu.edu.cn
**E-Mail: szhw1985@yahoo.com.cn
Online published on 7 November, 2012.
We assessed the algaicidal potential of mangrove plant Bruguiera gymnorrhiza on microalgae Phaeocystis globosa and Heterosigma akashiwo as target species. The aqueous leaf extracts of B. gymnorrhiza significantly inhibited the microalgae growth. The inhibitory effects of B. gymnorrhiza on microalgae were algae species dependent. Peak inhibitory rates (IR) in microalgae P. globosa and H. akashiwo were 97.4% and 90.1%, respectively. The sensitivity of both microalgal species to B. gymnorrhiza allelopathy were variable, P. globosa was more sensitive than H. akashiwo. Heat treatment did not change the algicidal potential of B. gymnorrhiza extracts (P> 0.05). Microscopic observation showed that the extracts severely damaged the cell membranes of microalgae and the microalgal cells were expanded and ruptured.
Allelopathic effects, Bruguiera gymnorrhiza, Heterosigma akashiwo, Inhibitory rate (IR), microalgae, Phaeocystis globosa
