Ajeet Kaur ¹

Affiliations
1 Botany Division, Forest Research Institute New Forest, Dehradun, IN

Abstract

Thirteen rhizobial isolates were obtained from the ischolar_main nodules of Albizia lebbek seedlings from different places and tested for nodulation, growth on different combinations of carbon and nitrogen sources, tolerance against heavy metals, salt and antibiotics. Five rhizobial isolates were selected to study nitrogen fixation potentional in A. lebbek seedlings during the active growth period (June to November) under glass house conditions. Both the isolates from Kiratpur Sahib (Punjab) viz., V(1) and V(2) were found highly resistant to heavy metals as well as salt. The mean generation time estimated for the isolate VI(1) was 3.38 h. Second order polynomial regression equations established between A₆₂₀ and cell count for the isolates II(2) and VI(1) showed high coefficient of determination. The maximum 620 nodular dry weight (0.782 g) was recorded in seedlings inoculated with isolate IV(1) followed by III(2) in September. Seedlings inoculated with isolate III(2) from Lalpani maintained overall high nitrogenase activity throughout the active growth period.

Keywords

Antibiotic Resistance, Salt Tolerance, Heavy Metals, Nodules, Nitrogenase Activity.

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Ajeet Kaur ¹, S. P. Chaukiyal ¹, P. C. Pandey ¹, T. C. Pokhriyal ¹

Affiliations
1 Forest Research Institute, Dehradun, IN

Abstract

Rhizobia were isolated from active nodules of Albizia lebbek and Dalbergia sissoo from different sources and confirmed against nodulation test. Several other physiological and biochemical tests were also performed. They were then multiplied in Yeast Extract Mannitol (YEM) broth and inoculated into their respective A. lebbek and D. sissoo seedlings. These were maintained under pot culture conditions in the glass house for few months to study the effect of inoculation treatments on nodulation, nitrogen fixation and biomass production. It was found that A. lebbek seedlings inoculated with rhizobial isolates of Lalpani gave the highest nodular biomass, specific and total nitrogenase activity. In case of D. sissoo, isolate from Asharori resulted in highest nitrogenase activity under pure culture conditions and maximum nodular number, nodular biomass, collar diameter and plant height as compared to other inoculation treatments. No relationship between nitrogenase activities of rhizobial isolates under pure culture and symbiotic conditions was observed. It may be concluded that both the isolates of Lalpani and that of Asharori may be utilized for the forestry programmes of planting A. lebbek and D. sissoo respectively.

Keywords

Albizia lebbek, Dalbergia sissoo, Seedlings, Nitrogenase, Biomass, Nodule, Rhizobium.

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