Screening of Pochonia chlamydosporia brazilian isolates as biocontrol agents of Meloidogyne javanica

Abstract

Pochonia species can occur in many Meloidogyne-infested soils throughout the world. The objective of this work was to isolate Pochonia species from different Meloidogyne-infested soil locations in Brazil and to screen for potential isolates effective in controlling Meloidogyne javanica under glasshouse conditions. A total of 29 isolates were identified as Pochonia chlamydosporia. Among them, 65.52% were identified as P. chlamydosporia var. chlamydosporia and 34.48% as P. chlamydosporia var. catenulata. For the glasshouse experiments, fungal chlamydospores were incorporated into the soil (5000 g soil^−1) and one tomato seedling was transplanted in 300 mL pot. After one week, each plant was inoculated with 1000 eggs of M. javanica. The isolates 1, 2, 3, 4, 9, 10, 21, 24, 28 (from Brazil) and 64 (from Spain) were the most efficient in reducing the number of eggs of the nematode. These isolates were re-evaluated in another glasshouse experiment, this time the number of eggs was increased (3000), inoculating both eggs and chlamydospores at the same time. After one week of inoculation, a tomato seedling was transplanted in each pot. In this experiment, isolates 64 and 10 were the most efficient in reducing the number of eggs by 72% and 60%, respectively.