Selection of Tn5::lacZ mutants isogenic to wild type Azospirillum brasilense strains capable of growing at sub-optimal temperature

  • Rajeev Kaushik
  • A.K. Saxena
  • K.V.B.R. Tilak


Azospirillum brasilense strains, CDJA and A40, capable of growing at sub-optimal temperature were tagged with stable chromogenic marker Tn5-lacZ. Mutants were screened for plant growth promoting activities at 20, 22, 25, 30 and 37 °C. Mutants MC48 and MA3 were found to fix nitrogen upto 85% and produced indole acetic acid (IAA) and siderophore in isogenic manner to their respective wild type strains, CDJA and A40, at sub-optimal temperatures. Co-inoculation of mutants with their respective parent (1:1 ratio) to the wheat revealed that colonization potential of the mutants was affected greatly. Tn5-lacZ tagged mutants MC48 and MA3 were found isogenic to their respective wild type Azospirillum strain, with regards to plant growth promoting activities and root colonization ability.

Azospirillum root colonization sub-optimal temperature Tn5-lacZ 


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Copyright information

© Kluwer Academic Publishers 2000

Authors and Affiliations

  • Rajeev Kaushik
    • 1
  • A.K. Saxena
    • 2
  • K.V.B.R. Tilak
    • 2
  1. 1.Division of Environmental SciencesIndian Agricultural Research InstituteNew DelhiIndia
  2. 2.Division of MicrobiologyIndian Agricultural Research InstituteNew DelhiIndia

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