23 Kas 2024 Cumartesi
PCR-RFLP pattern analysis of entomopathogenic nematodes isolated from agro-ecosystem for implicating their genetic diversity
Abstract :Entomopathogenic nematodes (EPNs) (Rhabditida: Steinernematidae and Heterorhabditidae) were isolated from cultivated lands in Karur region of Tamil Nadu, India. The ITS (internal transcribed spacer) rDNA sequence similarity of isolated EPNs revealed that the nematode strains Steinernema siamkayai, S. pakistanense and Heterorhabditis indica were more prevalent in cultivated eco-systems of that region. PCR-RFLP patterns obtained from 10 different restriction enzymes have shown that these strains were phylogenetically are more or less closely related within species, but they are genetically diverse from location to location in that region. Among 25 nematode strains, 19 strains were phylogenetically related to S. siamkayai (strain CM2) isolated from Belgium. Three strains of Steinernema sp. were related to S. pakistanense strain isolated from USA and remaining three Heterorhabdus sp. similar to H. indica strain cohen 21 from USA. Thus, intra-specific relationships among strains of these nematodes would emphasis that geographic distribution and environmental conditions may be associated to bring such genetic variations and divergence in the genomes of the nematodes
Steinernema, Heterorhabdus, Cultivated lands, ITS region, PCR-RFLP, Genetic variation