EFFECT OF THE PSEUDOMONAS AERUGINOSA ON POTATO CYST NEMATODE GLOBODERA PALLIDA

Abstract

The purpose of this study was to evaluate the efficiency of Pseudomonas aeruginosa strain Dokkala (OK383444) isolate against cyst nematode Globodera pallida strain Dokkala (MZ959187) as a biocontrol agent on potato cyst nematode. The test was first conducted in vitro with bacterial suspensions at 10⁵, 10⁶, 10⁷ and 10⁸ CFU/mL against 100 eggs, 100 second-stage juveniles (J2), and 10 cysts of G. pallida and then in vivo on potato variety Desiree infested by cyst nematode in the greenhouse. Four plant growing parameters were evaluated in the treated potato plants by P. aeruginosa in the presence of G. pallida; plant height (cm), tuber weight (kg), wet and dry weight (kg) of the aerial part, and root length (cm). The application of P. aeruginosa in vitro reduced the rate of eggs of G. pallida by 42% and juveniles by 56%. However, the percentages of colonized females with bacteria were not significant (8% and 16% after 96 and 240 h, respectively), whereas normal J2 controls hatched at 100% after 48 h. Furthermore, the in vivo treatment showed an enhancement of 650 g in tuber weight and 19.2 cm in plant length compared to untreated G. Pallida infested plants and 33.34% colonized cysts. This research clearly indicates the ability of P. aeruginosa to reduce the density of potato cyst nematodes and has the potential for the biological control of G. pallida.