Distinction of gametophytes and tetrasporophytes by microfluorometry in Osmundea pinnatifida (Rhodophyta) from Canary Islands

Abstract

In Osmundea pinnatifida gametophytic and tetrasporophytic plants can be distinguished on the basis of the different DNA content of nuclei in cortical and outer medullary cells obtained from subapical parts of the thallus. No significant differences exist between the two life cycle phases in the DNA content of nuclei of epidermal cells and medullary cells with 10 or more nuclei. Mixed phase thalli producing spermatangia and tetrasporangia have DNA contents in cells with 2–9 nuclei that correspond to gametophytic plants. In central and basal parts of the thallus, cortical and medullary cells of gametophytic and mixed phase thalli attain nuclear DNA content values similar to those in the respective tetrasporophytic cells. 1C nuclei contain about 0.23 pg DNA.