Effect of the Temperature and Light Intensity on the Growth of Zoospore Germling of Kjellmaniella crassifolia Miyabe (Laminariales, Phaeophyceae) in Culture

Abstract

Zoospore germlings of Kjellmaniella cyassifolia Miyabe were cultured at various temperatures (5, 10, 15, 20, 25°C) and light intensities (10, 20, 40, 80μmol/m²/s) under a photoperiod of 14 L: 10 D (light: dark) in a modified Grund medium for 6 weeks. Effects of temperature (5, 10, 15, 20, 25°C) on maturation of the gametophytes and growth of sporophytes were observed at a light intensity of 20μmol/m²/s for 13 weeks. Rapid growth of gametophytes were observed at 20°C and 80μmol/m²/s. However, the gametophytes did not mature and produce sporophytes at 20°C regardless of light intensities. Sporophytes were produced from the female gametophytes after fertilization at 5-15°C . Rapid growth of sporophytes in a flask and an aquarium was observed at 5°C. Sporophytes did not grow at 20°C and 25°C. The highest temperature for survival of the gametophytes and sporophytes was similar to those of Laminaria species in Hokkaido.