Effects of Indigenous and Commercial Rhizobia on Growth and Nodulation of Soybean (Glycine max L) under Greenhouse Condition

Abstract

Background: Soybean (Glycine max L.) is the most vital grain legume crop rich in protein and oil. The inoculation of rhizobia with soybean plays a very important role in increasing soil fertility via its contribution to biological nitrogen fixation. Objective: This study focuses on the evaluation of indigenous and commercial rhizobia on soybean nodulation and growth parameters. Methodology: Soil samples were collected from five districts for nodule trapping. The rhizobia were isolated using ‘plant induction following the standard procedures. The greenhouse experiments were arranged in a completed randomized design with three replications and two control units. The data were collected for plant height, nodule number, nodule dry weight, shoot dry weight, root length; root dry weight, total nitrogen and nitrogen-content. Results: The entire isolates were found gram-negative, without absorbing congo-red and did not grow on peptone glucose agar media. Slow grower isolates turned bromothymol blue with yeast extract mannitol agar medium into a moderately deep blue color but fast grower changed to yellow color. All isolates were tested on the sand induced nodule and were significantly superior to the negative control in terms of plant height, shoot dry weight, and nodule dry weight. The shoot dry weight of soybean rhizobial isolates on the sterilized sand experiment was ranging from 1.6 to 2.2g per plant and it was a highly significant correlation to the nodule number, nodule dry weight and root dry weight. Conclusion: The indigenous isolates were highly competent to all commercial rhizobia. This study encourages further evaluation of the field and molecular characteristics.

Unlocking the Potential of Inoculation with Bradyrhizobium for Enhanced Growth and Symbiotic Responses in Soybean Varieties under Controlled Conditions

“…Inoculation increased the root dry weight of the varieties with specificity to the strains. Similarly, 26 and 100 % increase in root dry weight due to inoculation was reported by Miljaković et al [16] and Desta et al [18], respectively. In the Boshe and Jalale varieties 75% (6 strains out of 8 inoculated strains), 50% (4 strains out of 8 inoculated strains) improved the root dry weight compared to the negative control, while in Gishama, Hawassa-04, and Awassa-95, 37.5, 25, and 12.5% of inoculant strains improved the root dry weight, respectively.…”

“…Inoculation of soybean with Rhizobia also significantly improved root dry weight [17]. An increase in root dry weight due to inoculation was reported by Miljaković et al [16] and Desta et al [18].…”

“…Correspondingly, Ahmad et al [38] found that the application of KNO3 under waterlogged conditions improved maize growth characteristics. Desta et al [18] also found the highest shoot dry weight from the N-treated plants compared to the rhizobia-inoculated soybean crop.…”

“…Miljaković et al [16] reported 15 % increase in plant height in soybean crop due to Bradyrhizobia inoculation. Desta et al [18] also found a 75 to 150% increase in soybean plant height due to inoculation. In contrast, Roriz et al [31] found that indigenous soybean isolates excelled over introduced strains in promoting plant growth and enhancing iron uptake.…”

“…Other studies by Argaw [12] and Księ żak and Bojarszczuk [32] support these findings, showing the significant impact of inoculation, and genotype x inoculation interaction on nodulation performances of soybean genotypes under both field and greenhouse conditions. Similarly, Desta et al [18] emphasized the significant importance of rhizobial inoculation to enhance the number and dry weight of soybean nodules. Inoculation of Jalale with strains SB-113 and SD-53, and Awassa-95 with strain SD-53 demonstrated the highest nodulation performance (Table 4).…”