Abstract
Azospirillum brasilense Cd cell concentration of 105-107 colony-forming units (cfu)/L applied 24 h before Rhizobium (106 cfu/mL), increased nodule formation in the non root hair zone, more than twofold, in pouch-grown Medicago polymorpha and Macroptilium atropurpureum seedlings, compared with Rhizobium alone. The increase in nodule formation in pouch-grown Trifolium alexandrinum following preinoculation with Azospirillum was 20%. The percentage of nodulated seedlings rose from 0 to 25% when Medicago polymorpha was preinoculated with Azospirillum followed by the application of 10 cfu/mL Rhizobium meliloti, a level which by itself was not sufficient to initiate nodule formation. Acetylene reduction activity in Medicago polymorpha and Macroptilium atropurpureum seedlings after inoculation with Azospirillum-Rhizobium was markedly increased. A possible reason for the increased susceptibility to Rhizobium infection may be that Azospirillum stimulates the formation of a larger number of epidermal cells that differentiate into infectable root hairs.
Original language | English |
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Pages (from-to) | 510-514 |
Number of pages | 5 |
Journal | Canadian Journal of Microbiology |
Volume | 33 |
Issue number | 6 |
DOIs | |
State | Published - 1987 |