Preliminary Studies On Sex Differentiation And Blossoming Habit Of Dioscorea Zingiberensis

Vegetative reproduction plants of Dioscorea zingiberensis are used as experimental material in this research . The sex type of Dioscorea zingiberensis and change of sex in vegetative reproduction process are investigated. External hormone are used on the regulative experiment to adult plant's sex performance, and the habits of blossoming are carefully observed. The main conclusions are following.1. Dioscorea zingiberensis have six kind of sexe types, namely male plant, female plant, monoecism in different stem, female and male in the same stem with different branch, female and male in the same branch with different inflorescence and female and male in the same inflorescence with different flower. The latter four kind of types may be called as monoecism.2.The flower of Dioscorea zingiberensis has the typical characteristic of monocotyledon, the basic number of flower is 3. The female flower keeps the trace which the stamen degenerates, when the male flower blossoms the powder disperses.3. The 1st time blossoming peak of Dioscorea zingiberensis female plant appears during the 4th days after the plant begin to blossom, the male plant achieve the 1 st time blossoming peak during the 7-8th day after the plant begin to blossom; The male plant have generally 2 time blossoming peaks in the blossoming process, but only 70% female plants have 2 time blossoming peaks.In the majority populations, the male plant bagin to blossom early for 3-4 days compared to femalein in average.4.After the different Dioscorea zingiberensis populations are introduced to Changsha, they are different in the blossoming habit, moreover the climatic condition's difference of original growth places is bigger, the difference of blossoming habits is bigger too, mainly manifested in the beginning time of blossoming . Because every population's stage of full bloom is long , therefore every population's flowering season can meet mutually. The blossoming intensity of Dioscorea zingiberensis has positive correlation with the temperature, and have negative correlation with the relative air humidity.5.The sex of majority of all plant can maintain stably, the sex stability of different plant lines in the vegetative reproduction process has variance, the sex stability of the minority lines are very strong which are raw material in female line and male line breeding.6. Plant external hormone 6-BA and IAA may induce the female flower from the Dioscorea zingiberensis male plant; GA3 depresses the reproductive growth of Dioscorea zingiberensis .