中国鹅掌楸混合芽的发生和形态建成

THE OCCURANCE AND ORGANOGENSIS OF MIXED BUD OF LIRIOD ENDRON GHINE NSE

本文继中国鹅掌楸花芽分化细胞形态学观察的研究之后,我们又系统观察了混合芽从发生至花器官建成的形态变化、芽的类型和分布以及芽端生长点的细胞形态学,试图为鹅掌楸属的系统学研究、植物性分化的生理学研究和种子品质的遗传学研究提供基础资料和理论依据。

The ontogeny of the mixed bud and floral organogensis were studied for Liriodendron chinense (Hemsl.) Sarg. by using optical microscopy and scan- ning electron microscopy. It was found that the mixed bud would take three years from its occurence to anthesis. The transformation from vegetative initi- ation 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 gro- wth. Occurence 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 initia- tion 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 characteris- tics and the percentage of seed setting have been discussed in this paper.