Rhizosphere microbial community of the nickel hyperaccumulator, Alyssum serpyllifolium subsp. lusitanicum

摘要

Rhizosphere microbial populations may enhance metal bioavailability, plant growth and resistance to metals. Physiological groups of soil microorganisms associated with three populations of the Ni hyperaccumulator, Alyssum serpyllifolium, and the non hy peraccurnulator, Dactylis glomerata, and their resistance to Ni, Co and Cr, were evaluated. Alyssum serpyllifolium harbours greater densities of heterotrophic bacteria, ammonifiers and amylolytics, and Ni- and Co- resistant bacteria. However, this was only observed in two of the three populations studied. Metal tolerance followed the order Ni>Co>Cr. In all three populations, Alyssum serpyllifolium enhanced densities of amylase-producing bacteria at the rhizosphere.