Assessment of nematicidal activity of Beauveria bassiana (Bals.-Criv.) vuill on Pratylenchus thornei (Sher et Allen) (Tylenchida: Pratylenchidae)

Abstract

In this study, nematicidal activity of two different isolates (BY2 and BIM-001) of the Beauveria bassiana (Bals.-Criv.) Vuill was investigated on Pratylenchus thornei Sher et Allen) (Tylenchida: Pratylenchidae) using culture filtrates and spore suspensions. Three spore suspensions (1x106, 1x107, 1x 108 spore/ml) and four culture filtrate concentrations (1X, 10X, 20X, 50X) were tested in the study. Depending on the treatment; 2 ml of spore suspensions or culture filtrates in different concentrations of both isolates and 400 larvae+adults from P. thornei were transferred to 6 mm petri dishes. The dead nematodes were counted under a light microscope after 24 and 72 hour and their mortality rate (%) were calculated. The nematicidal effect of culture filtrates of B. bassiana BY2 and BIM-001 isolates on P. thornei was found to be higher than the spore suspension. It was determined that the 1X concentration of culture filtrate of B. bassiana BY2 reached 100% mortality rate on P. thornei after 24 hour. After 72 hours, 10X (99.0%) concentrations of BY2 isolate and 1X (100%) and 10X (93.2%) concentrations of BIM isolate showed similar nematicidal activity with the commercial nematicide Velum (97.6%). On the other hand, after 72 hour, P. thornei mortality rate was 75.5% and 64.1%, respectively, at a concentration of 108 spore/ml of B. bassiana BY2 and BIM-001 isolates. This study will contribute to the development of a new control method as an alternative to the use of crop rotation and resistant cultivars in the control of P.thornei.