Colonization of pepper roots by a plant growth promoting Pseudomonas fluorescens strain

The effect of a Pseudomonas fluorescens strain (Aur 6) isolated from Lupinus hispanicus on pepper seedlings (Capsicum annum cv. Roxy) was studied. This strain had already shown its capacity as a plant growth promoting bacteria (PGPB) on seedlings of Lupinus albus, Pinus pinea and Quercus ilex. Strain Aur 6 significantly enhanced all biometric parameters measured: fresh weight, height, neck root diameter and slender index (height/neck root diameter). The PGPB effects could be related to auxin and siderophore production, as strain Aur 6 produced substances of both classes in pure culture. For a further monitoring of Aur 6 in the rhizosphere, strain-specific monoclonal antibodies were developed. Using the strain-specific it could be proofed that Aur 6 is an effective and persistent colonizer of pepper roots, but it is not able to behave as an endophyte.