SPORE GERMINATION OF FRANKIA STRAINS ISOLATED FROM COLLETIA-HYSTRIX AND RETANILLA-EPHEDRA (RHAMNACEAE)

Two Frankia strains, ChI1 from Colletin hystrix and ReI6 from Retanill a ephedra, were assayed to determine the germinability of their spores and the stages of the life cycle in different media. In BAP medium, b oth strains showed approximately 18% spore germination. However, in BA P medium lacking micronutrients and FeEDTA, strain ChI1 spores exhibit ed approximately 53% germination and strain ReI6 spores about 42%. The survey also showed that the spores were not heat-resistant, the ReIG spores being more sensitive than ChI1 spores. Both strains exhibited a small increase in their percentage of germination with a 15-pulse ult rasonic treatment.