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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #333164

Research Project: Host Plant Resistance and Other Management Strategies for Nematodes in Cotton and Peanut

Location: Crop Protection and Management Research

Title: Genotyping single spore isolates of a Pasteuria penetrans population occurring in Florida using SNP-based markers

Author
item Joseph, Soumi - University Of Florida
item Schmidt, Libby - Syngenta Crop Protection
item Timper, Patricia - Patty
item Mekete, Tesfa - University Of Florida

Submitted to: Journal of Applied Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/30/2016
Publication Date: 12/14/2016
Citation: Joseph, S., Schmidt, L.M., Danquah, W.B., Timper, P., Mekete, T. 2016. Genotyping of single spore isolates of a Pasteuria penetrans population occurring in Florida using SNP-based markers. Journal of Applied Microbiology. 122:389-401.

Interpretive Summary: The aim of this study was to examine genotypic variation and virulence characteristics of a population of bacterial parasite of root-knot nematode (RKN), Pasteuria penetrans, isolated from Florida. Six single spore lines (ssp), 16ssp, 17ssp, 18ssp, 25ssp, 26ssp, and 30ssp were generated by infecting individual nematodes with single spores from a field population of P. penetrans isolated from the peanut root-knot nematode. Genetic variability between the ssp lines was determined in six protein-coding genes and the 16S rRNA gene. Variation in the 16S rRNA gene among the ssp lines was observed while no variation was observed in the protein-coding genes. The lines 16ssp and 30ssp showed the highest rates of spore attachment on different species and populations of RKN while the line 18ssp had the lowest attachment rate. The polymorphism in 16S rRNA gene is taxonomically useful in biotype differentiation of P. penetrans and each biotype within a population show varying levels of adhesion and infection phenotype to different populations and species of RKN. This study gives detail on the heterogeneity existing within a population of P. penetrans and also shows that in vitro mass production of generalist spore genotypes might achieve broad RKN control

Technical Abstract: The aim of this study was to examine genotypic variation and virulence characteristics of a population of bacterial parasite of root-knot nematode (RKN), Pasteuria penetrans, isolated from Florida. Six single spore lines (ssp), 16ssp, 17ssp, 18ssp, 25ssp, 26ssp, and 30ssp were generated by infecting individual nematodes with single spores from a field population of P. penetrans isolated from Meloidogyne arenaria. Genetic variability between the ssp lines was determined based on sequence polymorphisms in six protein-coding genes and the 16S rRNA gene. An average of one SNP for every 69 bp was observed in the 16S rRNA partial sequence while protein-coding sequences did not show any variation among the ssp lines. The lines 16ssp and 30ssp showed the highest rates of spore attachment on different species and populations of RKN while the line 18ssp had the lowest attachment rate. The polymorphism in 16S rRNA gene is taxonomically useful in biotype differentiation of P. penetrans and each biotype within a population show varying levels of adhesion and infection phenotype to different populations and species of RKN. This study gives detail on the heterogeneity existing within a population of P. penetrans and also shows that in vitro mass production of generalist spore genotypes might achieve broad RKN control.