Antagonistic effects of natural Pseudomonas putida biotypes on Polymyxa betae Keskin, the vector of Beet necrotic yellow vein virus in sugar beet

Abstract

This in vivo study investigated the ability of fluorescent Pseudomonas spp. to suppress Polymyxa betae, a vector of Beet necrotic yellow vein virus causing rhizomania in sugar beet fields. For this purpose, the Pseudomonas putida biotype A (PpA) and biotype B (PpB) were isolated from sugar beet growing areas in Samsun, Turkey and with indicated suppression of P. betae were used against P. betae as a biocontrol agent. Firstly, PpA and PpB were applied to the roots of sugar beet seedlings of rhizomania-susceptible (cv. Arosa) and partially resistant (cv. Leila) cultivars. Statistical differences were not significant among PpA, PpB, Leila and Arosa culti-vars within rhizomania infested soil treatments, and there were also no significant differences among PpB and control groups (P> 0.05). In contrast, the partially resistant cultivar Leila with rhizomania free soil, PpB and negative control were significantly different from the other treatments (P> 0.05). Furthermore, numbers and diameters of the resting spores were significantly reduced by PpA and PpB treatments. In the treatments with PpA and PpB, a positive effect was observed on sugar beet weight and growth.