Characterization of Rhizobium sp (SAR-5) isolated from root nodule of Acacia mangium L.

The use of efficient strain of Rhizobium is of prime importance for optimum N2 harvest through legumes. The present investigation on microsymbiont associated with root nodulation of Acacia mangium L., an important forest species having wider adaptability. Certain biochemical and molecular techniques were used to characterize the microsymbiont. The 16S rRNA sequence was submitted to NCBI (National Center for Biotechnology Information) with an assigned accession number as MH 661260 (SAR-5). The dendrogram revealed that the strain MH 661260 (SAR-5) was Rhizobium alamii, exhibiting maximum similarity with Rhizobium mesosinicum strain: NR 043548. The maximum indole acetic acid (89.00 μg/mL) was produced by metabolizing glucose followed by fructose (70.4 μg/mL), mannitol (55.8 μg/mL), lactose (51.4 μg/mL), sucrose (46.2 μg/mL), starch (39.6 μg/mL), galactose (30.6 μg/mL) and maltose (26.4 μg/mL) and the least (16.5 μg/mL) was recorded in control. The plateau stage of growth was attained after 36 h of inoculation, but the exopolysaccharides (EPS) production was the highest (112 μg/mL) at 48 h after inoculation, thereafter reduced in yeast extract mineral medium. The most preferable carbon, nitrogen, and vitamin for EPS production were maltose, L-asparagine, and L-ascorbic acid, respectively and the least preferable were sucrose, KNO3, and riboflavin, respectively. The isolate (SAR-5) could survive in the pH range of 6 to 8 and the salinity level up to 3% NaCl in laboratory conditions

Characterization of Rhizobium sp (SAR-5) isolated from root nodule of Acacia mangium L.

327-333The use of efficient strain of Rhizobium is of prime importance for optimum N2 harvest through legumes. The present investigation on microsymbiont associated with root nodulation of Acacia mangium L., an important forest species having wider adaptability. Certain biochemical and molecular techniques were used to characterize the microsymbiont. The 16S rRNA sequence was submitted to NCBI (National Center for Biotechnology Information) with an assigned accession number as MH 661260 (SAR-5). The dendrogram revealed that the strain MH 661260 (SAR-5) was Rhizobium alamii, exhibiting maximum similarity with Rhizobium mesosinicum strain: NR 043548. The maximum indole acetic acid (89.00 μg/mL) was produced by metabolizing glucose followed by fructose (70.4 μg/mL), mannitol (55.8 μg/mL), lactose (51.4 μg/mL), sucrose (46.2 μg/mL), starch (39.6 μg/mL), galactose (30.6 μg/mL) and maltose (26.4 μg/mL) and the least (16.5 μg/mL) was recorded in control. The plateau stage of growth was attained after 36 h of inoculation, but the exopolysaccharides (EPS) production was the highest (112 μg/mL) at 48 h after inoculation, thereafter reduced in yeast extract mineral medium. The most preferable carbon, nitrogen, and vitamin for EPS production were maltose, L-asparagine, and L-ascorbic acid, respectively and the least preferable were sucrose, KNO3, and riboflavin, respectively. The isolate (SAR-5) could survive in the pH range of 6 to 8 and the salinity level up to 3% NaCl in laboratory conditions

Exploring the Role of Mycorrhizal and Rhizobium Inoculation with Organic and Inorganic Fertilizers on the Nutrient Uptake and Growth of <i>Acacia mangium</i> Saplings in Acidic Soil

Strong and healthy saplings are a prerequisite to establish a successful forest. Therefore, an attempt has been made to develop the best package for nutrient supplementation to raise healthy Acacia mangium saplings, especially in acidic soil. The seeds were sown in pots, receiving different combinations of Arbuscularmycorrhizal (AM), Rhizobium inoculation with application of lime, and mustard oil cake (MOC). The highest spore count and infection percentage (3220 kg−1 soil and 69) were recorded in the AM + MOC + R treated pot, whereas the lowest (2553 kg−1 soil and 37) were recorded in the AM + L treated pot. Nitrogen concentration and uptake in the sapling were higher in the Rhizobium-inoculated treatments than the uninoculated ones. The sulfur concentration and uptake were higher in the MOC-supplemented treatment. Similarly, the P, K, Ca, and Mg concentrations and uptakes were higher in the limed treatments than the unlimed ones. The micronutrient concentration and uptake were higher in the unlimed treatments compared to the lime practice. The concentration of N in Rhizobium-treated pots, P and K in lime-treated pots, and S in MOC-treated pots were increased, whereas the soil pH decreased in all treatments except in the integrated package (AM + MOC + R + L) after 120 days. The Ca and Mg were reduced in all treatments, whereas micronutrients were reduced in all packages except the control. Under different nutrient management practices, plant height and stem girth continuously increased by 9.5 to 12 cm and 3 to 4 times, respectively. The production of robust saplings required integrated application of lime, MOC, AM, and Rhizobium in an acid soil that facilitated better root growth with availability of adequate nutrients for saplings

Exploring the Role of Mycorrhizal and Rhizobium Inoculation with Organic and Inorganic Fertilizers on the Nutrient Uptake and Growth of Acacia mangium Saplings in Acidic Soil

Strong and healthy saplings are a prerequisite to establish a successful forest. Therefore, an attempt has been made to develop the best package for nutrient supplementation to raise healthy Acacia mangium saplings, especially in acidic soil. The seeds were sown in pots, receiving different combinations of Arbuscularmycorrhizal (AM), Rhizobium inoculation with application of lime, and mustard oil cake (MOC). The highest spore count and infection percentage (3220 kg&minus;1 soil and 69) were recorded in the AM + MOC + R treated pot, whereas the lowest (2553 kg&minus;1 soil and 37) were recorded in the AM + L treated pot. Nitrogen concentration and uptake in the sapling were higher in the Rhizobium-inoculated treatments than the uninoculated ones. The sulfur concentration and uptake were higher in the MOC-supplemented treatment. Similarly, the P, K, Ca, and Mg concentrations and uptakes were higher in the limed treatments than the unlimed ones. The micronutrient concentration and uptake were higher in the unlimed treatments compared to the lime practice. The concentration of N in Rhizobium-treated pots, P and K in lime-treated pots, and S in MOC-treated pots were increased, whereas the soil pH decreased in all treatments except in the integrated package (AM + MOC + R + L) after 120 days. The Ca and Mg were reduced in all treatments, whereas micronutrients were reduced in all packages except the control. Under different nutrient management practices, plant height and stem girth continuously increased by 9.5 to 12 cm and 3 to 4 times, respectively. The production of robust saplings required integrated application of lime, MOC, AM, and Rhizobium in an acid soil that facilitated better root growth with availability of adequate nutrients for saplings