UBC Theses and Dissertations
Cyto-morphological study of Prasiola meridionalis Akintobi, Samuel Oyewole
A culture study of the morphology, cytology and life cycle of Prasiola meridionalis was conducted. The alga was grown successfully in Provasoli's culture medium (1958) at a temperature of 5°C, and alternate periods of eight hours of light and sixteen hours of darkness. In culture, gametes are liberated only when mature reproductive or fruiting thalli are first illuminated for two hours with fluorescent light and then kept in the dark for several hours at temperatures of 3°- 5°C. The results of the study have indicated that the life cycle presents a dimorphic alternation of generations. The gametophytic tissue and gametes represent the haploid generation, and the sporophytic tissue and zygote the diploid generation. Meiosis is intermediate in the life cycle, occurring in the adult sporophytic cells. Sixteen chromosomes were observed in the diploid cells, zygote, aplanospores and somatic cells. Sexual reproduction is oogamous. The bi-flagellate micro-gamete is smaller than the macro-gamete which has no flagella. Asexual reproduction is accomplished by germination of aplanospores. Thalli which develop from germination of aplanospores and from zygotes appear the same morphologically.