关键词: 中国鹅掌揪, 混合芽, 系统演化

Abstract: The ontogeny of the mixed bud and floral organogensis were studied for Liriodendron chinense (Hemsl.) Sarg. By using optical microscopy and scanning electron microscopy. It was found that the mixed bud would take three years from its occurrence to anthesis. The transformation from vegetative initiation to flower initiation took place in June of the next year. The pattern of floral organogenesis was similar to that of helical phyllotaxis in the orders of floral envelope, stamens and pistils accompanied with the periodical apex growth. Occurrence of floral organs in one plant was unsynchronous, lasting for 1 to 3 months. The meristem of flower initiation was divided into five zones, which were perianth, central-mother cell, transition, rib meristem, and peripheral zone. The mixed bud initiation differed with vegetative initiation in the precocity of axillary and differentiation structure. The ratio of mixed bud to vegetative bud in the upper, middle and lower of a crown were 9.5/1,0.5/1 and 0.25/1 respectively. The significance of the mixed bud morphogensis on morphglogy, and the relation of morphological characteristics and the percentage of seed setting have been discussed in this paper.

Key words: Liriodendron chinense (Hemsl.) Sarg., Mixed bud, Systematic evolution