Role of bacterial bioagent, Pasteuria penetrans in the management of root knot nematode, Meloidogyne incognita by altering the lifecycle

Abstract

Pasteuria penetrans is a bacterial hyper parasite of nematodes. The influence of P. penetrans infestation on life cycle of root knot nematode was studied in tomato. One day after inoculation, 40.0 per cent of P. penetrans encumbered J2 and 63.7 per cent of healthy J2 had penetrated into the roots of tomato (t>0.05) showing that J2 parasitized by the hyper-parasite were less infective than the healthy one. Infection of M. incognita by P. penetrans resulted in slight delay in the completion of life cycle. The duration of all post-parasitic stages of the parasitizing nematodes took longer time for development and the adult stage was reached in 30 days as against 24 days for non-parasitized nematodes. Sex ratio was affected by P. penetrans infection. Number of males produced were high from healthy J2 when compared to the P. penetrans- infected. P. penetrans-infected females were milky white in colour and males were filled with spores. As a result of lower parasitization by nematodes, fewer galls were formed when plants were inoculated with P. penetrans-encumbered J2. The number of galls under inoculation with P. penetrans-infected J2 were 18.3/plant as against 35.0/plant when inoculated with healthy juveniles (t>0.05). Influence of P. penetrans on delaying nematode lifecycle and various developmental stages are discussed in this research paper.