Development of Bacterial Parasite, Pasteuria penetrans of Root-Knot nematode, Meloidogyne javanica in rabi Season and Poly-House Conditions in North India

In a screen-house experiment to study the development of Pasteuria penetrans during rabi season under north Indian conditions, it was observed that the life cycle of host nematode Meloidogyne javanica was prolonged; although eggs were formed in the genital tracts of females but no egg masses were formed till the end of March. The sporogenesis phase of P. penetrans did not occur in any of the five sets inoculated on different dates. P. penetrans development was restricted to vegetative phase only (microcolonies and thallus stages). The nematode development continued albeit slowly; while that of bacterium failed to synchronize with that of nematode. In another experiment the development of P. penetrans was studied under open-field and polyhouse (ordinary and hi-tech) conditions in winter season. Poly-houses (both ordinary and hi-tech) enabled raising the maximum temperature by 10-12 °C during day time, but there were negligible differences in the minimum temperatures. M. javanica completed its life cycle (females with egg sacs) in 60 days in hi-tech, 70 days in ordinary poly-house and 80 days in open-field conditions. P. penetrans development could not keep pace with that of nematode and it stopped at thallus stage. No mature endospores were found. P. penetrans failed to curtail the reproduction of M. javanica even in hi-tech poly-house, although infection did take place.