Biological potential of Ascophyllum nodosum extract on rhizobial diversity in nodules of mothbean Vigna aconitifolia Jacq. via Amplified Ribosomal DNA Restriction Analysis

Abstract

Aim: The aim of this study was to use Ascophyllum nodosum for potentially increasing the growth and rhizobial diversity in nodulating rhizobia in Vigna aconitifolia. Methodology: Different concentrations of Ascophyllum nodosum extracts (0.01%, 0.02%, 0.05%, 0.10% and 0.50%) were applied via foliar spray and on roots of Vigna aconitifolia. Growth characteristics and Amplified Ribosomal DNA Restriction Analysis were conducted to detect the morphological and molecular changes in rhizobial diversity. The restriction profiles thus obtained were used to study the rhizobial communities via Cluster analysis and Dendrogram using NTSYS-PC program and UPGMA constructed. Results: Roots treated with 0.05% Ascophyllum nodosum extract showed best growth of plants. This concentration not only proved best for the aggregation of nodules but also for obtaining enormous rhizobial diversity. Interpretation: Ascophyllum nodosum is a modern, cheap, non-toxic natural biofertilizer and Amplified Ribosomal DNA Restriction Analysis represents a favorable alternative to culture dependent method for assessing rhizobial diversity in nodulating bacteria.