不同溶剂提取芦竹化感物质对铜绿微囊藻生长的影响

Growth of Microcystis aeruginosa Affected by Allelochemicals of Arundo donax Linn. Extracted with Different Solvents

研究并比较了3种极性不同的有机溶剂(甲醇、乙酸乙酯、正己烷)提取的芦竹(Arundo donaxLinn.)化感物质对铜绿微囊藻生长的影响.通过跟踪观察藻细胞形态,测定藻细胞密度和细胞大小,发现3种溶剂提取物对铜绿微囊藻均有抑制作用.抑藻作用出现早晚次序:甲醇提取物<乙酸乙酯提取物<正己烷提取物.随作用时间的延长,投加低浓度甲醇提取物藻细胞生长恢复明显,高浓度抑藻效果较乙酸乙酯提取物及正己烷提取物弱.高浓度乙酸乙酯提取物、正己烷提取物在分别作用2 d、4d后,抑藻效果均接近100%.各溶剂提取物的半效应质量浓度(EC50,6 d)分别为甲醇提取物0.17 g.L-1,乙酸乙酯提取物0.05g.L-1,正己烷提取物0.08 g.L-1.研究同时发现,投加甲醇提取物藻细胞空洞化,投加乙酸乙酯提取物藻细胞空洞化、破碎以及部分抱团,投加正己烷提取物藻细胞出现褶皱及聚团现象.各溶剂提取物均引起铜绿微囊藻细胞体积减小,其中乙酸乙酯提取物的效果最强.

To study the effects of allelochemicals of Arundo donax Linn. on the growth of Microcystis aeruginosa, the allelochemicals were extracted with three solvents （ methanol, ethyl acetate and hexane ）, respectively. Based on the observation of algal morphology and the measurement of algal density and cell size, the results showed the allelochemicals extracted with all the three solvents had inhibition on M. aeruginosa. The appearance time of allelochemical inhibition increased as follows, allelochemicals extracted with methanol 〈 ethyl acetate 〈 hexane. As treatment time extended, M. aeruginosa regrew at low doses of allelochemicals extracted with methanol. Their inhibitory effects at high doses were lower than those extracted with ethyl acetate and hexane. After 2 d and 4 d of treatment, the inhibition ratios of allelochemicals extracted with ethyl acetate and hexane reached almost 100% , respectively. The 50% effective concentrations（EC50.6d ） of allelochemicals extracted with methanol, ethyl acetate and hexane were 0.17 g·L^-1, 0.05 g·L^-1 and 0.08 g·L^-1, respectively. The allelochemicals extracted with methanol caused cavities in cells, those with ethyl acetate caused cells into cavities, pieces and conglomeration, and those with hexane caused goffers on cells initially with conglomeration later. The allelochemicals extracted with all the three solvents decreased the cell size of M. aeruginosa, among which those extracted with ethyl acetate had the strongest action.