香蕉花芽分化期的生物量及其养分含量的变化

Changes of Biomass and Nutrient Contents during Banana's Floral Bud Initiation and Differentiation

通过田间试验、组织切片镜检和养分化学方法,研究了香蕉花芽分化各阶段的组织形态、植株各部位生长量和养分含量变化规律。结果表明:(1)香蕉花芽分化分为3个阶段:即花孕育期、花序分化期和花器各部原基分化期,3个阶段的生长量可作为花芽分化期的鉴别指标;(2)花孕育始期,叶片养分氮、磷、硫含量达到高峰,花孕育期至花序分化期迅速下降,而钾、钙、镁则相反,花器各部原基分化期各种养分变化均趋平稳;(3)叶片是香蕉花芽分化期营养诊断的理想部位。

An attempt was made t o study the changes of histological morphology, the biomass and nutrient contents in different parts of banana plant during the stages of floral initiation and differentiation through field experiment, microscopical identification on paraffin cut section, and chemical analysis of nutrient contents. According to the histolog!cal morphology of the banana plant at different vegetative stages, floral initiation and differentiation of the banana plant was obviously divided into three stages： floral initiation, inflorescence differentiation, and floral primordium differentiation. The plant biomass at the three stages of floral initiation and differentiation might be applied as basic morphological identification indexes for floral initiation and differentiation. The leaf nitrogen, phosphorus and sulfur contents rose to the peak at the early stage of the floral initiation but dropped rapidly from the floral initiation to inflorescence differentiation stages, whereas the leaf potassium, calcium and magnesium contents were just the opposite. All macronutrients in floral organs were changed steadily at the floral primordium differentiation stage. The leaves were found to be the best part for nutrient diagnosis as compared to other parts of the plant such as pseudostem and corm.