大百合花序分化及生理生化特征

Inflorescence differentiation of Cardiocrinum giganteum and its morphological and physiological-biochemical characteristics

为探究大百合花序分化进程以及发育过程中内源激素和营养物质的生理生化变化,以大百合鳞茎为试材,采用扫描电镜对大百合花序分化过程中不同阶段的形态进行观察,同时通过选择性反应/多反应监测技术(SRM/MRM)质谱分析法测定不同分化时期内源激素及可溶性糖、可溶性蛋白的含量。结果显示:大百合花序分化过程可划分为6个阶段:花序未分化期、花序原基分化初期、苞片原基分化期、小花原基分化期、花被片分化期和花芽分化完成期;花序发育过程中,吲哚-3-乙酸(IAA)和赤霉素(GAs)总体呈上升趋势,表明高水平IAA和GAs有利于花序以及花器官的分化;玉米素核苷(ZR)和水杨酸(SA)为先升后降的单峰变化,二者在分化中期起到较为积极的调控作用;1-氨基环丙烷羧酸(ACC)和茉莉酸(JA)总体呈下降趋势,推测是解除了对花序(芽)发育的抑制作用;高比值的IAA/GA_(3)与cZR/GA_(3)有利于大百合从营养生长向生殖生长转换;可溶性糖含量总体呈上升趋势,可溶性蛋白含量呈下降趋势,二者变化趋势完全相反。总体看来,ZR对大百合苞片原基和小花原基等新器官的形成起重要作用,IAA和GAs在花芽分化后期形态建成作用更显著;较高的可溶性糖含量可以促进大百合花序(芽)的发育,高水平的蛋白质是分化前期花器官形态建成的需要;大百合花序分化过程中小花发育存在渐趋同步的特点。本研究结果为大百合开花机制研究以及花期调控提供了理论依据。

In order to explore the morphological development and physiological-biochemical change in flower bud differentiation of giant lily,bulbs of Cardiocrinum giganteum were used as experimental material.The process of inflorescence differentiation was observed by scanning electron microscope.The physiological indices at different stages of differentiation were measured by SRM/MRM technique.The results showed that:The inflorescence differentiation process of C.giganteum could be divided into 6 stages,which were undifferentiation period,start of inflorescence primordium differentiation period,bract primordium differentiation period,floret primordium differentiation period,perianth differentiation period,flower bud differentiation completed period,respectively.Both IAA and GAs showed an increasing trend,indicating that high levels of IAA and GAs were beneficial to the differentiation of inflorescence and floral organs.ZR and SA both showed a pattern of increase-decrease,and they played an active regulatory role in the middle stage of differentiation.ACC and JA declined continuously,which may be due to the release of inhibition on the development of inflorescences.High IAA/GA_(3)-o-cZR/GA_(3) ratio was conducive to the transition from vegetative growth to reproductive growth of C.giganteum.The changes in soluble sugar and soluble protein contents were completely opposite,suggesting that the two components regulated the process of flower formation through equilibrium relationship.In general,ZR plays an important role in the formation of new organs such as bract primordium and floret primordium,and IAA and GAs play more significant roles in flower bud morphogenesis at the late stage of inflorescence differentiation.Higher soluble sugar content can promote the development of inflorescence and bud,and a large amount of protein is needed to supply the flower organ morphogenesis in the early stage of differentiation.During the whole process of inflorescence differentiation of C.giganteum,the development of florets is gradually synchronized.This study provides a theoretical basis for the study of flowering mechanism and flowering regulation of C.giganteum.