Landbauforschung (Dec 2020)

Co-inoculation with rhizobia and mycorrhizal fungi increases yield and crude protein content of cowpea (Vigna unguiculata (L.) Walp.) under drought stress

  • Pereira, Sandra,
  • Singh, Shweta,
  • Oliveira, Rui S,
  • Ferreira, Luis,
  • Rosa, Eduardo,
  • Marques, Guilhermina

DOI
https://doi.org/10.3220/LBF1607613362000
Journal volume & issue
Vol. 70, no. 2
pp. 56 – 65

Abstract

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Recent trends in sustainable agricultural production seek improved bioinoculants that can improve crop adaptation and production and reduce external inputs of pesticides and synthetic fertilisers, particularly under abiotic and biotic stress conditions. Drought is one of the critical and more frequent conditions that can drastically reduce plant bio-mass and yield. In this sense, the use of bioinoculants is a biological strategy to mitigate climate change and reduce the water needs of plants. Leguminous plants are very important in improving sustainable cropping systems because they can form effective symbiotic associations with both nitrogen-fixing bacteria and arbuscular mycorrhizal fungi. These microorganisms can act as an alternative source of nitrogen and can increase phosphorus utilisation from soils and fertilisers. Cowpea is a multipurpose crop that has caused a great interest due to its resistance to abiotic stress. This pot experiment in a greenhouse with non-sterilised soil aimed to test the effect of three previously selected rhizobial bacteria (Rhizobium sp. (B1), Bradyrhizobium elkanii (B2) and Bradyrhizo bium sp. (B3)) and arbuscular mycorrhizal fungi (Claroideoglomus claroideum BEG210) on the yield and crude protein content of cowpea under drought conditions and also to compare the competitiveness of the inoculated bacteria with native rhizobial bacteria naturally present in the soil. The combined inoculation with each bacteria and arbuscular mycorrhizal fungi Claroideoglomus claroideumBEG210 was shown to increase the crude protein content of cowpea seeds in plants under drought stress (25 % of field capacity) by 13 %, 17 %, and 30 %, respectively. This study shows that these microorganisms are potentially resistant to drought and can be used as a biotechnological tool for sustainable agriculture under drought conditions.

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