Isozymal taxonomy of ten chlamydomonas strains isolated from Damietta county, Egypt

ABSTRACT

Ten strains of Chlamydomonas were isolated as unialgal, then axenic cultures, starting from algal samples collected from different sites and habitats of Damietta county. Biochemical taxonomy in the form of polyacrylamide gel electrophoresis of isozymal systems for malate dehydrogenase, glutamate dehydrogenase, alkaline phosphatase, acid phosphatase and alpha- esterase was employed in an attempt to improve the current taxonomic status of such microalgae depending mainly on morphological criteria. Data had been clustered in the form of similarity matrices and dendrograms. The eleecttrophoretic isozymal analysis of the ten Chlamydomonas species and strains showed the possibility of building up species groupings. Each grouping with an isozymal similarity which is good enough to tie its members together. These species groupings are suggested as follows a] C.sphagnophfla I and C.isphagnophila II. b] Casymmetrica, C.gloeogama and C.terricola c] C.sphagnophila III, C.debaryana and C.bicocca. Each of C.fimbryata and Ci.globosa didn't show isozymal similarity enough to fit to any of the above mentioned species groupings, and would rather stand as real independent genuine species by themselves. Although C.sphagnophila I and C.sphagnophila II showed strong isozymal relationships, they proved not to be identical and hence are suggested to be considered as two different varieties of the species sphagnophila. C.sphagnophila III, though it looks morphologically identical with C.sphagnofila I and C.sphagnophila II, its isozymal patterns showed to be dissimilar enough with them, so that it is better to split it as another different species rather than keeping it as a strain of the sphagnophila species. The present work shows the significance of biochemical tools to improve the taxonomy of microalgae and -necessity of using as many isozymal systems as possible and the risk of relying on one or two systems only