Endophytic and rhizospheric bacteria from Opuntia ficus-indica mill and their ability to promote plant growth in cowpea, Vigna unguiculata (L.) Walp

Abstract

Studies on the biodiversity of plants associated microorganisms play an important role in food production. Ficus-tree, Opuntia ficus-indica Mill, are cultivated in many nations worldwide intercropping with other cultures, like cowpea, Vigna unguiculata (L.) Walp. The objectives of this study were to isolate and determine the diversity of bacterial endophytes and rhizobacteria in cacti and their ability to solubilize phosphate, the nif presence, their ability to produce indole-acetic acid (IAA) and verify their efficacy to promote plant growth in cowpea plants. Bacteria were isolated from rhizospheric soils, from surface-sterilized stems and roots of plants collected in Brazil, in nitrogen-free medium, and identified through fatty acid analysis. Gram-negative bacteria comprised 63% of endophytic bacteria and 80% of rhizobacteria. Only 13% showed amplification of nifH gene. From the 68 bacterial strains, associated with cacti, 18% produced IAA, and the best results were observed in Agrobacterium radiobacter, Klebsiella trevisanii, Enterobacter agglomerans and Paracoccus denitrificans. Phosphate solubilization was observed in 6% of strains. None of the strains inoculated in cowpea plants promoted stem and foliar growth. Four percent of strains showed ability to increase the root dry matter compared to the control group (inoculated with a pool of indigenous semi-arid Rhizobium).

Root Nodule Preparation as a Low-Cost Inoculant for Cowpea

“…This shows how responses can change according to conditions such as plant age and, especially, when the treatments and cultivars are evaluated under field crop conditions. There is the action of the community of soil microorganisms that interact among themselves, promoting plant growth and increasing soil fertility through phosphate solubilization and also biological nitrogen fixation (Costa & Melo, 2012;Ryan et al, 2008). In addition, in both locations, there was a history of cowpea cultivation, reinforcing the idea of a well-established, N-fixing microbial community.…”

Harnessing bacterial strain from rhizosphere to develop indigenous PGPR consortium for enhancing lobia (Vigna unguiculata) production

“…da Braulio [ 14 ] isolated dizotrophic bacterial strains INPA 03–11B, UFLA 03–84, UFRB FA34C2-2 and did seed inoculation with Vigna unguiculata (L.) for enhancing plant tolerance, productivity and nutrient content (Nitrogen and Phosphorus). Costa and Melo [ 15 ], reported that the cowpea ( Vigna unguiculata ) inoculation with bacterial strains , Klebsiella trevisanii, Enterobacter agglomerans, Agrobacterium radiobacter, and Paracoccus denitrificans associated with Opuntia ficus-indica having nif H gene significantly increases plant growth and more nodulation in secondary roots due to more surface area for easily colonization of Rhizobium spp. and Bradyrhizobium spp.…”