| Abstrakt: |
Zoospore release and germling growth of endophytic Ulvella ramosa were examined under various temperatures (10, 15, 20, 25°C) × irradiances (20, 60, 100 μm° l photons m-2 s-1). Additional growth experiments were performed at different salinities (15, 25, 35, 45 psu) and daylengths (8, 12, 16 h). Growth of host Gracilaria vermiculophylla (Ohmi) Papenfuss was estimated under combinations of temperatures (15, 20, 25, 30°C) and irradiances (20, 60, 100 μmol photons m-2 s-1). Endophyte effects on the host growth were tested in the two temperatures (20, 30°C) and irradiances (60, 100 μmol photons m-2 s-1). Zoospore release was maximal at 20°C and 20 μmol photons m-2 s-1, and germlings grew best under 20°C and 60 μmol photons m-2 s-1. No salinity effect on the growth of endophytes was found but endophyte growth was maximal under the daylength of 12 h. G. vermiculophylla grew better at higher irradiances but no growth differences were found between temperatures of 15-30°C. The growth of host species was significantly inhibited by endophytes under 20°C and 60 μmol photons m-2 s-1, but host G. vermiculophylla grew well in the endophyte inactive culture conditions of 30°C and 100 μmol photons m-2 s-1. In conclusion, endophyte effects on the production of host G. vermiculophylla could be minimized by controlling cultivation depth and harvest period to inhibit endophyte activity. [ABSTRACT FROM AUTHOR] |
