Karyological studies on the genus Oedogonium Link (Oedogoniales, Chlorophyceae)

Abstract

Abstract Karyological investigations were made on five monoecious, five dioecious macrandrous, four dioecious nannandrous and two unidentified taxa of Oedogonium Link. Chromosome numbers in the various taxa range from n=9 to n=46. A survey of the chromosome numbers in Oedogonium Link suggests that aneuploidy has played a more efficient role than euploidy in the speciation of this genus. Furthermore, clear differences in the karyotypes of the taxa with common chromosome numbers indicate a positive role of chromosomal rearrangements in speciation of the genus Oedogonium. Although positive correlation between cell width, nuclear volume and the chromosome number could be made in most of the taxa studied, observations made with a few others displayed deviations. No definite correlation between chromosome number and chromosome size could be drawn, nor could chromosome number be correlated with the number of N.O. chromosomes. Occurrence of identical chromosome numbers and morphology in the male and female strain...