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Identification of nif
genes of heterotrophic and endophytic diazotrophs associated
with rice (Oryza sativa L.,) by targeted DNA finger
printing
T. C. Kumari
Sugitha and K. Kumar*
Department of Agricultural Microbiology, Tamil Nadu
Agricultural University, 641 003 Coimbatore, India.
*Corresponding author. E-mail:
azollakumar@rediffmail.com. Tel: +91422-5511294.
Accepted
30 May, 2008 |
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Heterotrophic and endophytic diazotrophs were isolated from
rhizosphere soil, rhizoplane, roots and stems of different
rice varieties. A total of thirteen isolates obtained were
subjected to acetylene reduction assay (ARA) and eight
isolates recorded significant amount of nitrogenase activity
in a range of 31.65 to 91.95 nmoles of ethylene mg-1
cells h-1. Targeted PCR fingerprinting
using nif H primers generated specific DNA band of
approximately 750 bp, confirming the presence of nif
genes in these isolates. Two isolates of heterotrophic
diazotrophs, HDM 7 and HDT 1, generated multiple bands
ranging from 500 – 1000 bp.
Key
words:
Acetylene reduction assay, endophytes, heterotrophs, nif
gene, targeted PCR fingerprinting. |
