| The insects of family Phoridae are critical pests in agriculture and health fields. It is a cosmopolitan species.So far, the research on phorid flies focused mostly on its morphological taxonomy and life habit and so on, while the reports about chromosome are scanty.This research was provided experimental materials by raising Megaselia spiracularis Schmitzand Dohrniphora cornuta (Bigot) artificially.The air-dryed method was used to study the karyotype of Megaselia spiracularis and Dohrniphora cornuta and observe morphological and behavior of chromosomes in the meiosis. Traditional sheeting method and fixed sheeting method were used to study the salivary gland polytene chromosomes of phorid flies. It was a foundmental work for the further study of genetic control, drug-resistant mechanism and system evolution research. The main results are as follows:(1) The karyotype of the phorid fly, Megaselia spiracularis consisted of three chromosome pairs, two of which were metacentrics, one was telocentric. The karyotype formula is 2n=6=4m+2t, The 1st chromosome pair was slightly longer than the 2nd pair, about two times as the 3rd pair. The karyotype model chart was drawed.(2) The karyotype of the phorid fly, Dohrniphora cornuta consisted of four chromosome pairs, three of which were metacentrics, one was telocentric. The karyotype formula is 2n=8=6m+2t. The length of first three pairs chromosomes are different slightly, decreasing progressively in turn. The 4th chromosome pair is the shortest of all, its length is one-sixth times as the 1 st pair. The karyotype model chart was drawed.(3) Using Spermary and Ovary of Megaselia spiracularis and Dohrniphora cornuta as materials, the air-dryed method was used to study the morphological and behaviors of chromosomes in the meiosis, Grasping the main characteristics of chromosomes in every phases of meiosis process.(4)Through observation on the behaviors of chromosomes in the meiosis of Megaselia spiracularis and Dohrniphora cornuta, and the chromosome karyotype in metaphase and anaphase, B chromosomes were not detected. (5)This study researches the structure and growth tendency of phorid flies' salivary gland. Using traditional sheeting method and fixed sheeting method prepares and observes phorid flies'salivary gland chromosomes, discovering that fixed sheeting method is suitable for making phorid flies' salivary gland chromosomes. It can obtain good extension, clear salivary gland chromosome grain. Moreover, through comparing, the salivary gland chromosome grain of Megaselia spiracularis is more clearly, bands and puffs emerged in chromosome. However, the salivary gland chromosome of Dohrniphora cornuta and Diplonevra peregrina don't have band Phenomenon, it is special in the salivary gland chromosome of Diptera. |
