Isolation, in vitro characterization and predaceous activity of an indian isolate of the fungus, Arthrobotrys oligospora on the root-knot nematode, Meloidogyne incognita

Abstract

An investigation was undertaken to isolate predaceous fungi from the soil and faecal matter of goat, sheep and cattle in the open grazing fields around Bangalore, Karnataka, India. An isolate of Arthrobotrys oligospora, PDBC AO1, was selected and the effects of temperature and pH on its development and its predaceous activity on Meloidogyne incognita were assessed under laboratory conditions. The fungus exhibited septate two-celled ovate-oblong conidiospores, trapping hyphae, and radiating and sparse mycelium. The optimum temperatures for its growth, sporulation, conidiospore germination and conidiospore production ranged between 25 and 35 °C, while pH optima ranged between 6.0 and 7.5. The optimum temperature for conidiospore germination was 25-30 °C. The isolate trapped 86% of second stage juveniles of the nematode and a maximum of 62% nematode juvenile mortality in 96 hours at 28 °C was recorded.