Study Of Karyotype And Banding On Chromosome Of The Dohrniphora Cornuta (Bigot)(Diptera:Phoridae)

Dohrniphora cornuta is widely disributed in various regions of the world. It is an important pest in the field of agriculture and public health. It has been found in corpse and used for forensic identification of insects. So far, the study on Dohrniphora cornuta was focus on morphological taxonomy and habits etc, while there were few reports on its chromosome research.In this study, the Dohrniphora cornuta was raise on simple feeding and its life history was observed and recorded. The mitotic chromosome preparations were made from cerebral ganglion in early pupal and the meiotic chromosome preparations were made from gonad in pupal with air dry method and stained with Giemsa or AgNO3. The karyotype, mitosis, meiosis and B chromosome was observed and analyzed. The main results were as follows:(1)The gonad was growing in early pupa, at the same time we could get mitotic chromosomes from cerebral ganglion. So we could make a distinguish between male and female from gonad before making chromosome preparation. In this way, the problem of chromosomes ambisextrous was solved.(2)The Dohrniphora cornuta have diploid chromosome numbers2n=8with three pairs of metacentric chromosomes and one pair of telocentric chromosome. The sex chromosome in Dohrniphora cornuta was particular short which only one-six of its euchromosome.(3)There was Somatic synapsis in mitosis of Dohrniphora cornuta. Its homologous chromosomes appear in pairs From prophase to metaphase.(4)In anaphase, the appearance of euchromosome looked like the shape of "V", but the sex chromosome looked like the short bar. This behavior proved that its euchromosome was metacentric and its sex chromosome was telocentric, therefore its karyotype formula was2n=8=6m+2T. (5)There were five stages in prophase of the first meiotic division and their continue time were different. The time of the stage longer one were more easier observed and the time length of different stages were various in different species. In Dohrniphora cornuta, it showed that zygotene, pachytene and diplotene appeared easily than leptotene and diakinesis.(6)There was no B chromosome in mitosis chromosome in cerebral ganglion and the meiosis chromosome in gonad no matter stained with Giemsa or AgNO3. All results showed that the nucleolus and sex chromosome stained deeper and stood out.