Distribution of allozymic genetic variability in populations of two chromosomal races and their hybrid zone of Dichroplus pratensis (Melanoplinae, Acrididae)

CHIAPPERO, M.B.; PARISE, C.; MARTÍ, D.A.; BIDAU, C.J.; GARDENAL, C.N

JOURNAL OF EVOLUTIONARY BIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2004 vol. 17 p. 76 - 82

1010-061X

We examined, through allozyme electrophoresis, the genetic structure of populations of the acridid grasshopper Dichroplus pratensis from two chromosomal races (Northern and Southern) and their hybrid zone in Argentina. No fixed alleles for any particular race were found, although geneticdifferentiation among parental races was significant (Fst=0.044, 95% CI: 0.004?0.068). Hybrid populations are genetically more similar to the Southern race (Fst=0.008, 95% CI:0.005?0.018) than to Northern ones (Fst=0.018, 95% CI: 0.002?0.030). Differential viability or fertility of hybrids, or asymmetry in mating preferences in favour of one particular cross would cause a higher proportion of matings between hybrid individuals and those from the Southern race. This would explain the high genetic similarity between those groups, in spite of their geographical vicinity with northern race populations.