桃果实内果皮发育过程中糖积累与木质素沉积的变化

 以中熟桃‘京玉’和‘大久保’果实为材料, 测定桃果实内果皮在细胞分裂和硬核期糖的含量, 分析糖积累的变化情况; 通过间苯三酚—HCl对‘大久保’桃果实内果皮进行染色, 观察木质素沉积的进程; 应用常规戊二醛—锇酸双固定法在透射电镜下观察内果皮细胞壁的发育进程。结果表明, 桃果实内果皮在花后40 d前, 细胞不断分裂增生, 初生细胞壁不断膨大, 糖的积累快速增长, 大约40 d时葡萄糖和果糖的积累量达到最高; 到40 d后, 糖含量及山梨醇代谢迅速下降。此时内果皮开始木质化, 内部逐渐呈现红色, 大约半个月后, 整个内果皮都变红, 木质素从内到外基本沉积完毕, 说明木质素沉积发生在糖积累高峰之后, 糖的大量积累为木质素前体的合成奠定了物质基础, 糖积累量的多少直接影响内果皮发育的好坏。

Studies of Changes in Sugar Accumulation and Lignin Deposition During Peach Fruit Endocarp Development

The experiment was conducted with peach ( Prunus persica L. ) ‘Jingyu’and ‘Okubo’fruits. The sugar content was measured in peach endocarp during the course of the cell division and pit hardening, analyzing the change of sugar accumulation, observing the development of endocarp cell wall through the transmission electron microscope (TEM) and detecting the p rogress of the its lignin deposition by staining with phloroglucinol - HCl reagent. The results showed the cell in the peach endocarp divided continuously, the primary cell wall expanding, the cell organ marginalizing gradually, which was the stage ofsugar rap id accumulation, before 40 days after full blooming. The internal part began red after more than 40 days, the lignin deposition finished after 15 days or so, sugar accumulation and dynamic metabolism decreased rapidly, which showed lignin deposition occurred after the peak of sugar accumulation. Its content had an important effect on endocarp development.