Growth requirements of Frankia strains isolated from Casuarina equisetifolia, and the influence of the isolates on the growth of the host plant.

Abstract

was isolated from the root nodules of L. seedlings, grown in a growth chamber, after inoculation with soil originating from an old east Kenyan casuarina forest. Optimum pH for the growth of the two isolates ranged from 6.4 to 6.9. The optimum temperature for their growth was 32°C. The growth of these cultures ceased at NaCl concentration above 2%. The influence of the isolates on the growth of the host plant was determined in a growth chamber experiment in which an American strain (HFPCc13) was used as a reference. The biomass of the inoculated seedlings was 2.4–4.1 fold those of the non-inoculated control seedlings at the end of the 7-month experiment.FrankiaCasuarina equisetifoliaFrankia