Competitiveness and rhizosphere colonization of Bradyrhizobium sp. strains on chickpea
Factors affecting competition among strains of Bradyrhizobium sp for nodulation of chickpea (Cicer arietinum L.) were investigated in the greenhouse. Nodule occupancy by two strains varied when tbe strains were co-inoculated either in Leonard jars on in soil pots, or when inoculum ratios of the strains were changed. In another experiment, early rizosphere dominance in root tips or total rizosphere did not reflect nodule occupancy, as all the nodules were formed by the soil-born strain, which represented less than 1% of the early rizosphere population. In a time-course inoculation experiment with 2-day-old chickpea seedlings, a delay in adding the secondary inoculum by 4 h increased the nodule occupancy of the primary strain from 16 to 94%. The results indicate that actual rates of strains are important only when the strains are inoculated together under the same conditions, but when different inoculation methods were used, rhizosphere numbers did not define nodule occupancy by the strains.
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| Format: | Digital revista |
| Language: | por |
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Pesquisa Agropecuaria Brasileira
2014
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| Online Access: | https://seer.sct.embrapa.br/index.php/pab/article/view/13471 |
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| Summary: | Factors affecting competition among strains of Bradyrhizobium sp for nodulation of chickpea (Cicer arietinum L.) were investigated in the greenhouse. Nodule occupancy by two strains varied when tbe strains were co-inoculated either in Leonard jars on in soil pots, or when inoculum ratios of the strains were changed. In another experiment, early rizosphere dominance in root tips or total rizosphere did not reflect nodule occupancy, as all the nodules were formed by the soil-born strain, which represented less than 1% of the early rizosphere population. In a time-course inoculation experiment with 2-day-old chickpea seedlings, a delay in adding the secondary inoculum by 4 h increased the nodule occupancy of the primary strain from 16 to 94%. The results indicate that actual rates of strains are important only when the strains are inoculated together under the same conditions, but when different inoculation methods were used, rhizosphere numbers did not define nodule occupancy by the strains. |
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