Ex vitro survival and early growth of Alpinia purpurata plantlets inoculated with Azotobacter and Azospirillum .

The survival rate, shoot and root dry mass, shout number, plant growth, stem height and diameter, number of leaves and root length were measured in micropropagated plantlets of Alpinia purpurata (Red ginger) inoculated with Azospirillum sp. 11B and Azotobacter sp. Pachaz 008 at 10(7), 10(8) and 10(9) cells cm(-3) using a complete randomized experimental design. Inoculation ofA. purpurata plantlets with the Azospirillum sp. 11B or Azotobacter sp. PACHAZ 008 strains induced larger stem diameter, root dry mass, number of shoots and increased their survival rate from 77 to 100% compared to plantlets without inoculation, while other plant characteristics were not affected.