Identification and characterization of Photorhabdus luminescensisolates from eastern dry zone of Karnataka.

*Dr. Sonia Bohra; Dr. M. K. Shivaprakash

Volume : VI, Issue : V, May - 2016

Identification and characterization of Photorhabdus luminescensisolates from eastern dry zone of Karnataka.

Dr. Sonia Bohra, Dr. M. K. Shivaprakash

Abstract :

<p>&nbsp;Photorhabdus luminescens is a nematode symbiotic, gram negative, bioluminescent bacterium, belonging to the family of Enterobacteriaceae. Recent studies reveal the importance of this bacterium as an alternative source of insecticides. Isolation and identification of native nematode&ndash;bacterial association in the field are necessary for successful control of endemic pests in a particular location. Twenty bacterial isolates from entamopathogenic nematodes were isolated by insect bait method using fifth instar larvae of Galleria mellonella. Bacterial isolates were identified and confirmed using standard synaptic keys. Further it was amplified by 16S rDNA primer. Percentage infection of G. mellonella larvae by entomopathogenic nematodes in soil across different locations was found twenty percent. Molecular diversity of these isolates was characterized by RAPD marker analysis. Primer screening was carried out using 10 primers, out of which 6 primers were detected for RAPD analysis. A total of 179 bands were scored, out of which 134 bands are polymorphic. The cluster analysis revealed that all the bacterial isolates clustered at a linkage distance of about 2 units on the dendrogram. Dendrogram shows the isolates as three major clusters. The percent polymorphism observed in the isolates was 74.87 which suggest that the symbiotic bacterial population exhibit genetic diversity.</p>