EFFECT OF CERTAIN ENVIRONMENTAL-FACTORS ON ZYGOSPORE GERMINATION OF SPIROGYRA-HYALINA

The present study focusses on the effects of pH, temperature, intensit y of white, red and far-red light on zygospore germination in the fila mentous green alga Spirogyra hyalina. Maximum germination of zygospore s occurred at pH 8.0 and 25 degrees C. Germination of zygospores was f avored by white light at an intensity of 3-4 klx. Red light resulted i n higher germination when applied at the beginning or in the middle of the dark period, while far-red light decreased zygospore germination. Red light in the middle of the dark period was found to be most effec tive for germination. These observations suggest a possible presence o f the phytochrome system in the test alga contributing to its morphoge netic response.