Genetic structure of <i>Tribolium castaneum</i> populations in mills

  • A. A. Semeao Department of Entomology, Kansas State University, Manhattan KS 66506. Email: aasemeao@ksu.edu
  • J. F. Campbell USDA ARS Center for Grain and Animal Health Research, 1515 College Ave, Manhattan KS 66502.
  • R. W. Beeman USDA ARS Center for Grain and Animal Health Research, 1515 College Ave, Manhattan KS 66502
  • R. J. Whitworth Department of Entomology, Kansas State University, Manhattan KS 66506
  • P. E. Sloderbeck KSU-Southwest Research and Extension Center, 4500 E. Mary St., Garden City KS 67846
  • M. D. Lorenzen Department of Entomology, North Carolina State University, Raleigh NC 27695

Abstract

We investigated the genetic diversity and differentiation among nine populations of Tribolium castaneum using eight polymorphic loci, including microsatellites and other insertion-deletion polymorphisms (=”indels”). Samples were collected in food processing/storage facilities located in Kansas, Nebraska, California, Louisiana, Florida and Puerto Rico. Standard population genetic analysis was applied, and an assignment test was used to assign individuals to their genetic population. All loci were polymorphic across populations, with the number of alleles per locus-population combination varying from three to fourteen. Among 72 locus-by-population combinations, 31 deviated significantly from Hardy-Weinberg equilibrium, which was associated with a deficiency in heterozygosity. Tribolium castaneum populations show some level of genetic structuring. Genetic differentiation between populations, using FST estimates, was significant, with FST varying from 0.018 to 0.149. AMOVA indicated that 8.32% of the variation in allele frequency resulted from comparisons among populations. Genetic distance was not significantly correlated with geographic distance. Correct assignment to the genetic population was possible in only 56% of all individuals. Together, these results revealed that geographically distinct populations of T. castaneum had low to moderate levels of genetic differentiation that was not correlated with geographic distance, and the genotypic profile of the individuals did not provide enough information for fingerprinting them with their source population. Keywords: Tribolium castaneum, Population genetics, Genetic structure, FST, Genetic fingerprinting
Veröffentlicht
2010-09-02