Strains of Paenibacillus promoters of the specific nodulation in the symbiosis Bradyrhizobium-caupi - DOI: 10.4025/actasciagron.v29i3.277

Abstract

The effect of Paenibacillus and Bacillus (Plant Growth Promoting Rhizobacteria - PGPR) strains on the symbiosis of the caupi [Vigna unguiculataM (L.) Walp.] with Bradyrhizobium sp. was studied in vases of Leonard. The caupi cultivar used was IPA-205. The plants were irrigated with an N-Free nutrient solution. The inoculations with PGPR promoted a better growth of the root in relation to the co-inoculations, as the S21 strain of P. polymyxa which was superior (70%) to the control (not inoculated). The PGPR increased the specific nodulation in the co-inoculated plants, evidenced by the positive correlation with the specific nitrogen accumulated. Indirect and direct effects on the specific nodulation were shown by the significant decrease of root growth (40%) and non-significant increase in the number of nodules (46%) in the Loutit (L) strain of P. polymyxa and LBF-410 strain of P. macerans. The PGPR, which stimulated the nodulation, can promote a better fixation of ^N2 during the symbiosis between Bradyrhizobium and caupi.