PHYLOGENETIC CHARACTERIZATION OF INEFFECTIVE FRANKIA IN ALNUS-GLUTINOSA (L.) GAERTN. NODULES FROM WETLAND SOIL INOCULANTS

Ineffective Frankia endophytes were retrieved from various wet soils b y using Alnus glutinosa clones as trapping plants. No pure cultures co uld be isolated from these ineffective nodules. Therefore, the phyloge netic position of these endophytes was determined by sequence analysis of cloned PCR products of bacterial 16S rDNA, derived from nodules. T he results showed that all nodule endophytes belong to a hitherto unde scribed cluster of the Fuankia phylogenetic tree. The position of thes e uncultured ineffective Frankia nodule endophytes is different from t hat of the ineffective Fuankia isolates derived from A. glutinosa nodu les, even when originating from the same geographical location. This s uggests a bias in current isolation techniques.