Study On Flower Bud Differentiation Of Brassica Japonica Sieb

The dynamic variation of flower bud differentiation and the dissect features of a new health protection vegetable-Brassica japonica Sieb, as well as the influence of different photoperiod, different concentration of gibberellin on the flower bud differentiation were studied using paraffin continuous sliding and entity dissect in order to provide some theory bases for collect seed etc. The main results were the following.The flower bud differentiation can be divided to two stages from the observation.The first stage was the inflorescence differentiation. It began after the transformation of main stem growing cone from vegetative growth to reproductive growth. The inflorescence consisted of main branch and 1-3 lateral branch.The second stage was the floral organ differentiation. It could be subdivided to four periods: calyx differentiation, petal differentiation, stamen differentiation and pistil differentiation. The sequence of floral organ differentiation was sepal primordium-* petal promordium- stamen primordium-pistil primordium, then septal, petal, stamen and pistil were formed, consequently bisexual flower formed.The differentiation of whole plant inflorescence was: the first lateral branch-the second lateral branch-main stem. However, to a single flower, the bud differentiation was which meant the differentiation began from the outer to the center of the bud.Different photoperiod had different effects on the flower bud differentiation of Brassica japonica Sieb. The results from SSR were: the period of flower bud differentiation of Brassica japonica Sieb for 24h light differed remarkable significantly from the other treatments, little difference was observed between the interruption of less than 10min at night from CK, and the other treatments differed remarkable significantly from CK. The earlier flower bud differentiation led to the lower height, less expansion and fewer leaves.The results from gibberellin treatment were: different concentration of gibberellin stimulated the flower bud differentiation. The times of flower bud differentiation after gibberellin treatment were earlier significantly than CK, and the earliest was the 5 times treated by 300 mg/l gibberellin. Treated differently are roughly the same compared with the result treated by photoperiod, that is, the earlier flower bud differentiation was found to lead to the lower height, less expansion and fewer leaves.