A. Karthikeyan;Natchimuthu Balasubramaniam Sivapriy

Institute of Forest Genetics and Tree Breeding, Coimbatore, Indi;Institute of Forest Genetics and Tree Breeding, Coimbatore, India

Mangroves;Bruguiera sexangula;Beneficial microbes;Nursery;Propagules;PLANT-GROWTH;SOLUBILIZING BACTERIA;MANGROVE RHIZOSPHERE;AZOSPIRILLUM;BIOFERTILIZERS;PROMOTION;CHINA;SOI

Bruguiera sexangula (Lour) Poir., a threatened mangrove tree, was inoculated with beneficial microbes in a nursery to assess any improvements in growth and biomass. From soil samples from the rhizosphere of B. sexangula in a mangrove forest in Panangadu of Kerala India, nitrogen-fixing bacteria Azotobacter chroococcum and Azospirillum brasilense were isolated. The phosphate-solubilising bacterium Bacillus megaterium and potassium-mobilizing bacteria Frateruria aurantia were also isolated and cultured on suitable media. Later, ripe propagules of B. sexangula were collected from matured trees and raised in sterilized soil bags (13 x 25 cm) containing sterilized soil and sand (2:1 ratio). The cultured beneficial microbes were propagated and used to inoculate the ripe propagules of B. sexangula and maintained in the nursery for 6 months. After 6 months, growth and biomass of the inoculated propagules were greater than for the uninoculated control propagules. Shoot length, number of leaves, stem girth and root length were also significantly greater than in the controls. This study showed that the mangrove-specific beneficial microbes influenced the growth of B. sexangula in the nursery and will help in the establishment of B. sexangula in degraded mangrove forests.