Phenotypic characterization and symbiotic effectiveness test of chickpea (Cicer arietinum L.) rhizobia isolated from Dejen and Aneded Districts, East Gojjam Zone, Amahara Region, Ethiopia

Abstract

Chickpea (Cicer arietinum L.) is an important leguminous crop grown in different parts of Ethiopia.It is a nutritionally valued and N 2 -fixing legume which forms a symbiotic association with Mesorhizobium. This study was conducted to characterize and evaluate symbiotic efficacy of chickpea rhizobia isolated from soil samples collected from the study area. Seventeen chickpea rhizobia were isolated by soil host plant trap method and characterized for edaphic stress tolerance. Five of the isolates were grown at high temperature of 45°C and salt concentration of 6%, whereas seven were grown at acidic pH of 4, and four were grown at basic pH of 9. All isolates were not resistant to kanamycin, while fair resistance to erythromycin and streptomycin and modest resistance to ampicillin and azithromycin were observed. Furthermore, most of the isolates showed a variation in nodulation with higher (22 NN/p) and lowest (9 NN/p) scores. Shoot dry weight (SDW) of the plant ranged from 1.18 to 1.84 g/p and isolates showed effective (67%) to highly effective (100%) N 2 -fixing performance. From these, four isolates showed multiple edaphic stress resistance and are recognized as promising candidate for chickpea production in stressed soil; however, further study in the filed is required.

Nodulation and Growth Promotion of Chickpea by Mesorhizobium Isolates from Diverse Sources

“…Interestingly, these findings were also supported by strong significant positive correlations of NFW with SDW and average heights. Variations in shoot dry weights and symbiotic effectiveness with regard to chickpea genotypes were also observed in Tunisia and Ethiopia [67,77]. On the other hand, there were no significant interaction effects between the two factors 'strains' and 'chickpea genotype' observed in this study, which is consistent with other reports conducted in the field [77] or pot experiments [76].…”

“…The shoots were dried in an air-circulating oven at 60 • C for 72 h after which shoot dry weight (SDW) was recorded. We then estimated relative symbiotic effectiveness (RSE) [67] using the formula…”

Plant Growth Promoting and Abiotic Stress Tolerant Chickpea (Cicer arietinum L.) Rhizobial Isolates from Some Areas of South Wollo Zone, Ethiopia

“…e difference between the maximum and minimum nodule number, nodule dry weight, and shoot dry weight of this study was 85, 86, and 15, respectively, whereas the study conducted by Refs. [21,22,40] reported very less results than the current findings indicating the effectiveness of the study of rhizobial isolates.…”

“…In this study, 34 (71%) of the isolates induced nodules and were authenticated as root-nodulating Rhizobium species, which is low as compared to the findings of Refs. [21,22,40], who reported 100% authenticated rhizobial chickpea isolates. Regarding nodule number, the maximum and minimum nodule number was recorded from plants inoculated with isolates Wu-36 and Wu-25 with nodule number of 85 and 1 p/plant, respectively, which is close to the result of Ref.…”

“…e potential of the rhizobial isolates to grow and tolerate several temperature ranges such as 5,10,15,20,25,35,40,45, and 50 °C was evaluated [1]. A loop full of rhizobial isolates grown on YEMA media were streaked and incubated by adjusting at the specific temperature for 3-4 days.…”