Wilkie John D, Sedgley Margaret, Olesen Trevor
Faculty of Arts and Sciences, The University of New England, Armidale, NSW 2351, Australia.
J Exp Bot. 2008;59(12):3215-28. doi: 10.1093/jxb/ern188. Epub 2008 Jul 24.
The intention of this review is to discuss floral initiation of horticultural trees. Floral initiation is best understood for herbaceous species, especially at the molecular level, so a brief overview of the control of floral initiation of Arabidopsis (Arabidopsis thaliana (L.) Heynh.) precedes the discussion of trees. Four major pathways to flowering have been characterized in Arabidopsis, including environmental induction through photoperiod and temperature, autonomous floral initiation, and regulation by gibberellins. Tropical trees are generally induced to flower through environmental cues, whereas floral initiation of temperate deciduous trees is often autonomous. In the tropical evergreen tree mango, Mangifera indica L., cool temperature is the only factor known to induce flowering, but does not ensure floral initiation will occur because there are important interactions with vegetative growth. The temperate deciduous tree apple, Malus domestica Borkh., flowers autonomously, with floral initiation dependent on aspects of vegetative development in the growing season before anthesis, although with respect to the floral initiation of trees in general: the effect of the environment, interactions with vegetative growth, the roles of plant growth regulators and carbohydrates, and recent advances in molecular biology, are discussed.
本综述旨在探讨园艺树木的花芽分化。对于草本植物，尤其是在分子水平上，花芽分化的机制已得到较好的理解，因此在讨论树木之前，先对拟南芥（Arabidopsis thaliana (L.) Heynh.）花芽分化的调控进行简要概述。在拟南芥中，已鉴定出四条主要的开花途径，包括通过光周期和温度的环境诱导、自主花芽分化以及赤霉素调控。热带树木通常通过环境信号诱导开花，而温带落叶树木的花芽分化往往是自主的。在热带常绿树芒果（Mangifera indica L.）中，低温是已知的唯一诱导开花的因素，但这并不能确保花芽分化一定会发生，因为它与营养生长存在重要的相互作用。温带落叶树苹果（Malus domestica Borkh.）自主开花，其花芽分化取决于花期前生长季节营养生长的各个方面，不过总体而言，本文还讨论了环境的影响、与营养生长的相互作用、植物生长调节剂和碳水化合物的作用以及分子生物学的最新进展。
