Cross-Nodulation and Symbiosis Efficiency of Rhizobia Isolated from Nodules of Cyamopsis tetragonoloba on Vigna unguiculata and Glycine max

• Published in: Russian journal of plant physiology 2023-12, Vol.70 (8), Article 182
• Main Authors: Belimov, A. A., Sazanova, A. L., Ulianich, P. S., Yuzikhin, O. S., Guro, P. V., Shaposhnikov, A. I., Sokolova, D. V., Safronova, V. I.
• Format: Article
• Language: English
• Subjects: Acetylene; Acetylene reduction; Biomass; Biomedical and Life Sciences; Bradyrhizobium; Cowpeas; Cyamopsis tetragonoloba; Food industry; Food plants; Genera; Industrial crops; Inoculation; Legumes; Life Sciences; Nitrogen; Nitrogen fixation; Nitrogenation; Nodulation; Nodules; Plant growth; Plant Physiology; Plant Sciences; Plant species; Research Papers; Roots; Soybeans; Strains (organisms); Symbiosis; Vigna unguiculata
• ISSN: 1021-4437; 1608-3407
• DOI: 10.1134/S1021443723601878

Guar ( Cyamopsis tetragonoloba (L.) Taub.) is an important legume plant used as food and industrial crop. Guar forms nitrogen-fixing symbiosis with nodule bacteria (rhizobia) supplying the plant with this important nutrient element. The ability to form symbiosis with rhizobia of various taxonomic groups of genera Bradyrhizobium and Ensifer is a common trait of guar with cowpea and soybean. Pot experiments were performed to compare nodulation and response of guar, cowpea and soybean to inoculation with nine strains isolated from guar nodules and belonging to the above-mentioned genera. Strains assigned to species Bradyrhizobium archetypum and Bradyrhizobium valentinum were isolated from nodules of guar for the first time. Nodule number and biomass on the inoculated guar roots significantly varied depending on the strain from 15 to 40 nodules per plant and from 20 to 54 mg dry weight (DW)/plant, respectively. Eight strains formed nitrogen-fixing symbiosis with cowpea. Nodule number and biomass on the cowpea roots varied depending on the strain from 19 to 67 nodules per plant and from 3 to 61 mg DW/plant, respectively. Significant differences among strains were also observed in acetylene reduction activity and positive effects of inoculation on shoot biomass and nitrogen content in shoots of plant species. However, symbiosis with soybean was inefficient, since only few small white nodules were observed and no effects were found on plant growth. Correlations between the symbiotic parameters in guar and cowpea dependent on the rhizobia strain were found and discussed in view of mechanisms underlying formation and functioning of nitrogen-fixing symbiosis. Several studied strains offer promise as inoculants for guar and cowpea and recommended for further field trials.