Significance of Calcium in the Fruiting of Chaetornium Species, Particularly Chaetomium globosurn

SUMMARY: Calcium is required by Chaetomium globosum for the normal formation of perithecia, but is not essential for vegetative growth. Calcium is at least partly replaceable by strontium or barium. Most of the other species of Chaetomium tested responded to calcium, either in fruiting or growth, or both. Suitable doses of calcium reproduce in a large measure the previously observed effect of jute extract on the fruiting of Chaetomium species. The presence of calcium in jute extract was established. It has been observed previously that growth and perithecial formation of Chaetomium globosum are markedly stimulated by a hot-water extract of jute fibre (Buston & Basu, 1948), and that the ash of this extract also has a some-what similar effect on this and other species of Chaetomium (Basu & Bose, 1950). The specific nature of the factors responsible was not established. Further investigation, embodied in the present paper, shows that calcium, which is present in jute extract, stimulates the fruiting of C. globosum. Light has also been thrown on the effect of some other trace metals on this fungus