Studies On Sex Related Genetic Markers Of Cannabis Sativa L.

Sex of high plant is determined by genetic factors.Besides,it is determined by the environment such as temperature,illumination and nutrition.Cannabis is a dioecious plant.Compared with that in female plant,fibre in male plant has higher quality.Besides,earlier maturing of male plant result in the inconvenience of mechanized harvesting.Therefore early and rapid identification of sex is desired in planting in order to select the expected sex to plant according to cultivated purpose and utilization orientation and make different gender grow separatively to save harvesting cost.Accordingly,the identification of Cannabis has been paid much attention.In this research, the differences between male and female cultivated varieties were studied by the analysis of morphology,cytology and molecular biology.This would be provide references for the early sex identification of Cannabis.This would also provide theoretical basis for further sex-determining mechanism study of Cannabis.The main results were showed as follows:1.The growth rates in male and female plants were almost the same at seeding growth stage,while the growth rates at rapid growth stage were apparently different,the male plant growed faster. Therefore the different growth rates in this stage between male and female plants can be used as a a reliable evidence in early sex identification. Length to width ratio of the seventh,eighth and ninth euphylla at seeding growth stage was apparently different.Accordingly,these can also be used as a reliable evidence in early sex identification.2.The only pairing of terminal end of chromosome was observed in pollen mother cells at diakinesis stage and one chromosome was larger than another.The results supported the existence of sex chromosome;One chromosome of bivalent at Metaphaseâ… was away from equatorial plate,which supported the existence of a pseudoautosomal region on sex chromosome.3.A male specific marker MADC348 was obtained in amplified restriction fragment polymorphism (AFLP).This marker provide reliable evidence in early sex identification at molecular level.It generated a 348bp male specific band,which was present in all male plant and absent in all female plant.As a result,this stable marker can be used as a reliable evidence in early sex identification.This marker provide theoretical basis in the discovering of sex control gene family and the study of location information of sex-related gene using fluorescence in situ hybridization (FISH).