|Development and life-cycle studies in Porphyra yezoensis (Bangiales, Rhodophyta) under axenic conditions|
Yamazaki, A.; Nakanishi, K.; Saga, N. (1999). Development and life-cycle studies in Porphyra yezoensis (Bangiales, Rhodophyta) under axenic conditions. Bull. Inst. Oceanic Res. & Develop., Tokai Univ. 20: 77-84
In: Bulletin of Institute of Oceanic Research and Development. Tokai University. Tokai University. Institute of Oceanic Research and Development: Shimizu. ISSN 0289-680X, more
|Authors|| || Top |
- Yamazaki, A.
- Nakanishi, K.
- Saga, N.
To better understand development phenomena in macro-algal tissue culture, we examined the morphogenesis of Porphyra yezoensis cultured aseptically in defined synthetic media. Generally, the filamentous sporphytic thalli of P. yezoensis were densely tufted with uniseriate filaments. Foliaceous gametophytic thalli were flat with multiple cell rows. In this study, axenic filamentous thalli retained their normal characteristics of morphogensis; there were no clear difference between morphogenetic traits in unialagal and axenic conditions. However, conchospores, which might have developed into the foliose form under unialgal conditions, germinated into callus-like masses under axenic conditions. Most of the gametophytes gradually lost their typical morphogenesis after the first longitudinal cell-division. Some of the callus-like masses developed rhizoid-like structures in several places or along the entire mass. These callus-like masses occasionally released monospores through asexual reproduction or carpospores through fertilization. Released monospores germinated into gametophytes which lose their morphology. However, released carpospores germinated into normal filamentous thalli again. Therefore, we concluded that P. yezoensis loses its typical morphogenesis only during the gametophytic phase in axenic cultures.