兜兰属植物花期调控研究进展

Advances in Flowering Regulation of Paphiopedilum

兜兰由于独特的花朵造型、绚丽的花朵色彩、持久的观赏花期而具有极高的观赏价值,是国际上的高档花卉。但由于生态环境的破坏以及人们对其过度采挖,兜兰现已成为世界上最濒危的植物物种之一,许多种类已濒临灭绝,所有兜兰野生种均被列入《濒危野生动植物种国际贸易公约》(CITES)附录I而被禁止交易。目前,市场上流行的兜兰品种大多是由台湾等地利用无菌播种获得的杂交种或少量原生种,但由于兜兰属植物的生长习性复杂、生长周期长、花期种间差异大,至今尚无有效的花期调控技术。兜兰为典型的合轴生长方式,花芽产生于每年开花前后从基部分蘖出的新侧芽。兜兰属植物为总状花序,具多花原基,多花种类(或品种)的副花同时或先后发育;单花种类(或品种)是由于副花花芽分化后停止发育所引起的。开花时间与开花丰度是2个非常重要的园艺性状。光照、温度、植物生长调节剂和肥料是影响植物开花的主要因素。对于主要分布在热带地区的兜兰属植物而言,光周期对其花期的影响不显著;温度是促进春花型兜兰从营养生长进入生殖生长的关键因素;赤霉素(GA3)和6-苄基嘌呤(6-BA)单独施用或结合施用均可以有效调控花期,一些单花种类利用植物生长调节剂可促进单花类的副花发育形成双花或多花;开花前定期喷施低浓度的含高磷高钾的水溶肥也可以有效提前花期。本文在对兜兰属植物生长习性、花芽分化方式和花期调控技术等相关研究进行综合分析的基础上,参考其他兰花花期调控的方法,提出了兜兰属植物花期调控技术及分子机制的主要研究方向,以期为兜兰属植物的花期调控及兜兰商品化生产提供参考。

Paphiopedilum species, popularly known as slipper orchids because of the resemblance of the pouch-shaped lip to a lady’s slipper, gorgeous flower color and long-lasting flowering, have captured the interest of many orchid growers and hobbyists and are one of the most popular and rare orchid genera being sold and exhibited today. Wild populations are under the threat of extinction as a result of over-collection, loss of suitable habitats, and all species are listed in the Convention on International Trade in Endangered Species of Wild Fauna and Flora(CITES) Appendix I and the trade is prohibited.At present, most of the popular Paphiopedilum species on the market are hybrids or a small number of native species obtained by asymbiotic seed germination in Taiwan and other places. Due to its long growth cycle, large differences among species and diverse flowering habits, it is difficult to achieve effective flowering regulation. Paphiopedilum has a sympodial habit of growth. After blooming, the plant will resume growth at the base of the previous shoot. The apical meristem of each new growing shoot continually differentiates its leaves until it initiates flower buds under proper environmental conditions. The Paphiopedilum is a raceme with polyfloral primordia. The dominant flower and lateral flower(s) of polyfloral species or varieties develope simultaneously or successively. However, the single flower species or varieties are caused by the cessation of development of lateral flower buds after differentiation. Flowering time and flowering abundance are two very important horticultural traits. Light, temperature, plant growth regulators and fertilizers are the main factors affecting plant flowering. For the Paphiopedilum species mainly distributed in tropical regions,the photoperiod has no significant effect on the flowering period. Temperature is a key factor to promote the growth of spring-flowered Paphiopedilum from vegetative growth to reproductive growth. Gibberellin(GA3) and 6-benzylpurine(6-BA) alone or in combination can effectively control the flowering period. The use of plant growth regulators in some monofloral species could promote the development of lateral flowers to form double or multiple flowers. Regular spraying of low-concentration water-soluble fertilizers containing high phosphorus and high potassium before flowering can also effectively advance the flowering period. This article reviews the related researches on the growth habit, flower bud differentiation and flowering regulation technology of Paphiopedilum. With reference to other methods of orchid flowering period regulation, suggestions for Paphiopedilum flowering regulation are put forward in order to provide reference for the research on the flowering regulation technology and the commercial production of Paphiopedilum.