Comparative Studies on The karyotypes of Three Species of Nematodes in The genus Neoaplect ana

This paper presents comparative studies of the karyotypes of three species of Neoaplectana nematodes.The karyotypes of the gonadal cells and the ombryonic cells of N.glaseri(NC513,85011),N,carpocapsae (DD-136) and N.bibionis were studied.Slides were made by the squash techniquc with orcein staining.The results obtained from this study indicate that three species of ncmatodes show a 2N condition of nine chromosomes for the males,ten for the females,but they are different in karyotypes from one species to another.(The karyotype formulae):N.glaseri (NC513,85011)2n=4m+6t(♀)2n=4m+5t(♂);N.carpocapsae (DD-136)2n=8m+2t(♀)2n=7m+2t(♂);N.bibionis 2n=6m+4t(♀)2n=5m+4t(♂).In the last part of this paper,we compared and analyzed the karyotypes of three species and discussed the evolutionary relationship of their karyotypes.