Toxicity of CuSo4 for growth and oogonium formation in Oedogonium hatei

Abstract

The effect of CuSO4 on the germination and growth of swarmers and subsequent induction of oogonia was studied in Oedogonium hatei Kam. (Oedogoniales, Chlorophyceae). A 0.05 mg/L concentration of the metal compound showed a stimulatory effect on the growth of the alga in comparison to control. Growth was inhibited at above 0.1 mg/L concentrations. The percentage of oogonia formed and the mature oogonia developed linearly decreased with increase in concentrations of CuSO4 employed. Two mg/L CuSO4 proved to be highly toxic to the growth and/or multiplication of zoospores and further development of sexual structures in this alga. The germination of zoospores and the growth of germlings were so markedly affected that induction of oogonia remained- completely inhibited at 2 mg/L CuSO4. A 3 mg/L concentration of CuSO4 proved to be completely lethal to asexual swarmers and no survival of zoospores was encountered in any case. © 1993 Folia Microbiologica.