抄録
The phylogeny of karyotypes was investigated in lower plants i. e., flagellata, algae and fungi. The most primitive plants, bacteria and Cyanophyceae have no nuclei in strict sense and no chromosomes. The nuclei of Protozoa such as Vorticella and Stentor suggest the origin of chromosomes (Fig. 2). The most primitive nucleus seems to have two chromosomes in haploid number. A large number of fungi has lower chromosome number and especially Ascomycetes and Basidiomycetes have two chromosomes in haploid number, while on the other hand, most algae have high chromosome number, especially Charophyta has many chromosomes, namely, from twelve to ca. 50 chromosomes in haploid number (of. Tab. 1). The most primitive type of Rhodophyceae, Bangia fusco-purpurea and Porphyra umbilicalis have also two chromosomes in haploid number and the other algae have higher chromosome number.
There are three modes of metabolism, namely heterotrophic one assimilating organic substance and autotrophic metabolism of which one assimilates inorganic substance by means of photosynthesis and the other assimilates by chemosynthesis. Osborn and Komarov supported that the chemo-autotrophic metabolism was most primitive, while Oparin suggests the most primitive organism assimilates organic substance which is abundantly produced in such environment, and inorganic substance such as oxygen and carbon dioxide seems to occur more rarely than in present. If this opinion is true, the heterotrophic organism such as fungi may be more primitive than autotrophic one such as algae in the mode of metabolism. Such primitive condition is also observed in karyotype phylogeny (Tab. 1). In short, the parallelism between the mode of metabolism and karyotype phylogeny was clearly demonstrated in fungi and algae.
