Physical Responses and Growth on Tissue Culture of Agarophytic Seaweed, Gracilaria fisheri (Xia and Abbott) Abbott, Zhang, and Xia (Gracilariales, Rhodophyta)

摘要

This study on Gracilaria fisheri tissue culture was aimed at optimizing the growth conditions for strain maintenance. Tissue culture experiments were conducted in four selected influential factors: salinity, fragment length, growing zone, and propagule density. Each experiment was subsequently completed with three replications, and the best result was used in the next study. The experiment on fragment length was conducted from 1 to 5 cm of subapical segments. The study on different salinity levels was completed in the range of 15-35 ppt. Different zones of tissues were selected as apical, subapical, and basal fragments for the next study. The study on different propagule densities was conducted from 1 to 8 g L-1. Each experiment was done for 40 days under 25 mu mol m(-2) s(-1) of light intensity and 12L:12D of photoperiod at a temperature of 25 +/- 2 degrees C. The result showed that optimal conditions for G. fisheri tissues existed at 2 cm of segment length under 20 ppt salinity and were part of the tissue from the apical zone and 1 g L-1 density. Under optimal conditions, the daily growth rate of G. fisheri tissues was 6.5% day(-1), and the final biomass was increased 12.4 times compared to the initial biomass. One finding of the study on physical performance of G. fisheri tissue was that only apical tissues grew with apicobasal polarity. The number and length of branches were seven branches per cm and 0.8 cm, respectively. Also, G. fisheri tissue that expressed as a stenohaline species was rather more affected by salinity than the other factors.