Bioassessment of Phylogenetic Relatedness and Plant Growth Enhancement of Endophytic Bacterial Isolates from Cowpea (Vigna unguiculata) Plant Tissues

Abstract

Cowpea is of great importance to people in most tropical countries of the world. It is the preeminent indigenous African legume and a frontline option for meeting the nutritional protein demands of people and livestock. The use of an eco-friendly alternative to synthetic fertilizers and agro-pesticides has, in recent times, become an attractive research theme. Therefore, bioprospecting for effective endophytic bacteria isolates as potential bioinoculants for enhancing cowpea productivity makes this research a priority. In this study, cowpea tissues were used to isolate and characterize endophytic bacterial strains through morpho-genotypic techniques and then assessed for their in vitro growth promotion, as well as their in planta growth potential in chamber experiments. In all, 33 endophytic bacterial strains were authenticated by sequencing the 16S rRNA and through further bioinformatics analysis. Also, plant-growth promoting (PGP) genes and seed germination percentage improvements were confirmed in the endophytic bacteria isolates. The research findings highlight that the bacterial strains are molecularly diverse and some of the authenticated endophytic bacteria isolates are potential bioinoculants that can be applied in further studies to improve the agronomic productivity of cowpea plant.