GERMINATION, STORAGE AND VIABILITY TESTING OF SEEDS OF ZOSTERA-CAPRICORNI ASCHERS FROM A TROPICAL BAY IN AUSTRALIA

The effects on the germination of Zostera capricorni Aschers. of sever al factors, including salinity, temperature and incising the seed coat were investigated and analysed using analysis of variance. We also in vestigated methods for estimating the viability of Z. capricorni seeds , and their storage life. Soaking the seeds in 0.5% tetrazolium at 25 degrees C for 18-24 h gave the most consistent staining pattern for te sting the viability of Z. capricorni seeds. This method can now be use d to ensure that seeds are viable before they are used in further stud ies of the germination and growth of seedlings or in rehabilitation pr ojects. Low salinities (1-10 parts per thousand) and incising the seed coat promoted rapid and almost complete germination of Z. capricorni, indicating the seeds do not have a primary dormancy. Temperature did not affect seeds in the lower salinities (1, 5 and 10 parts per thousa nd). However, at higher salinities (20, 30 and 40 parts per thousand) seeds only germinated at low temperatures (15 degrees C). In Moreton B ay, salinities are rarely as low as 1-10 parts per thousand; consequen tly Z. capricorni is most likely to germinate in winter, when temperat ure decreases. Paradoxically most Z. capricorni seeds are found in spr ing and summer, with very few present in winter. The most successful s torage of Z. capricorni seeds was at 5-10 degrees C in aerated water. Under these conditions 58+/-10% (SE) of these seeds were still viable after 50 days.