Collection and Germination of Sporocarps of Azolla caroliniana

Azolla caroliniana Willd. with matured mega- and microsporocarps were harvested from the field, sun dried and sieved to form balls of megasporocarps and massulae. The separated sporocarps were tested for germination in different media in Petri dishes under laboratory/greenhouse conditions. Only the swollen, green megasporocarps germinated. Nutrient medium was superior to a soil solution. The observed percentage germination was better on a solid surface than in a liquid medium. Germination did not occur with dark incubated sporocarps. The addition of phosphorus stimulated sporocarp germination and at a concentration of 30 ppm, an 86% increase in germination was noted against the control. Percentage germination varied widely with pH, and optimum germination was recorded at a neutral pH. The effect of nitrogen sources on sporocarp germination indicated that 70 ppm of nitrate, 7.5 ppm of ammonium, 15 ppm of nitrite and 15 ppm of urea increased germination by 51, 66, 44 and 63%, respectively; further increases in concentration inhibited germination. Treatment with 100 ppm of either kinetin or gibberellic acid, or a mixture of both, enhanced germination by 67, 55 and 84%, respectively.