Temporal dynamics and variation in the alfalfa root nodule and rhizosphere microbial communities of coastal sand and lawn soil

Abstract

Medicago sativa L. (alfalfa), a leguminous crop, is vital globally for forage, crop rotation, and soil fertility. Though, the microbiome of alfalfa grown in uncultivated land has not been studied yet. Here, we employed the high-throughput 16S rRNA and nifH gene amplicon sequencing to unravel the rhizosphere microbiome and nodules endosymbionts of alfalfa grown in poor lawn and coastal sandy soils. The root nodule of alfalfa of coastal sands and poor lawn soil, Sinorhizobia/Ensifer accounted for 80.599% and 67.727% of the total microbiome, respectively. The class Actinobacteria (except Frankiales) and order Rhizobiales, Sphingomonadales, Burkholderiales, Pseudomonas, and Cytophagia were found significantly enriched. Culturable studies displayed the dominance of Bacillus followed by Arthrobacter, Microbacterium, and Streptomyces. Hydroponics studies revealed the efficiency of cultured isolates for nodulation and plant growth attributes. Overall studies decipher the soil indigenous microbiome associated with root nodule and rhizosphere of Alfalfa grown in uncultivated coastal and sandy land.