DETECTION OF COLONIZATION BY PSEUDOMONAS PSIA12 OF INOCULATED ROOTS OF LUPINUS-ALBUS AND PISUM-SATIVUM IN GREENHOUSE EXPERIMENTS WITH IMMUNOLOGICAL TECHNIQUES

The plant-growth-promoting, non-diazothrophic strain Pseudomonas PsIA1 2, isolated from wheat rhizosphere, was used as inoculum for the legum es Lupinus albus and Pisum sativum. Root colonization of 8 week-old pl ants, under non-sterile greenhouse conditions, was assessed in both le gumes by a strain-specific polyclonal antiserum and a sensitive chemol uminescence immunoassay. Although the autochtone bacterial colonizatio n of the rhizoplane as well as of the root interior was similar in bot h plants, the roots of Lupinus albus were colonized by Pseudomonas PsI A12 more intensively than the roots of Pisum sativum. In the roots of Lupinus albus, the introduced strain contributed 50%, in pea roots onl y about 1% to the total bacterial population. Using the immunogold lab elling technique, microcolonies of the introduced strain were detected in the rhizoplane and in the inner root tissue of Lupinus albus.