Abstract:

The time course of the initiation of different types of apical primordia on the stem of wheat (Triticum aestivum L.) was investigated to establish a comprehensive pattern of apical primordium development and quantitative dynamic relationships among different primordium initiation. The results showed that the initiation of leaf and bracteal primordia took the S shape, and that of spikelet and floret took the rise stage of parabolic shape in relation to GDD (growing degree days after sowing) in wheat. The bracteal was much like vegetative rather than reproductive organ in terms of the dynamic pattern of primordium initiation. The progress of spikelet and floret primordium initiation could well reflect the characteristics of different genotypes and the impact of different ecological environments on wheat apical development. The integrated model of different primordium initiation in shoot of wheat was an S shaped curvilinear, and could be divided into three sub models. The number of leaf primordia was affected by both genotype and environment, while the numbers of bracteal, spikelet and floret primordia were affected mainly by environmental factors. Measured with mean thermochron, the rates of initiation of leaf, bracteal and spikelet primordia in normal planting were the highest among all the sowing date treatments. In contrast to the relationships among leaf, bracteal, spikelet and their initiation duration, the correlation between the number of floret and its initiation duration was highly significant.

小麦茎顶端原基分化的综合模式

李存东^1,2  曹卫星^1*  张月辰²

(1.南京农业大学农业部作物生长调控重点开放实验室,南京,210095；2.河北农业大学农学院,河北保定,071001)

摘要：研究了小麦(Triticum aestivum L.)茎顶端不同类型原基分化的动态过程,以明确原基分化的综合模式,并建立了不同原基分化之间的定量关系.结果表明,小麦叶原基和苞叶原基分化与播后累积生长度日(GDD, growing degree days after sowing)的关系呈S形曲线,而小穗原基和小花原基为上升段抛物曲线.从分化模式看,苞叶原基具备营养器官原基特征;小穗和小花原基的分化进程能较好地反映基因型和生态条件对顶端发育的影响.小麦茎顶端原基分化的综合模式为由三段子模式构成的近似S曲线.叶原基数由基因型和环境条件共同决定,而苞叶原基、小穗原基和小花原基数以环境因子的影响为主.以平均热间距来衡量,适期播种处理的叶片、苞叶和小穗原基分化速率最高;而小花原基数与小花分化持续期之间的数量关系最为密切.研究结果有助于揭示和理解小麦茎顶端发育的生物学规律.

关键词 小麦 茎顶端 原基分化 综合模式 动态特征

*通讯作者 Email: caow@public1.ptt.js.cn

Key words: wheat, shoot apex, primordium initiation, comprehensive pattern, dynamic characteristics