Vascular anatomy of Chinese jujube fruit

【Objective】To observe the anatomy structure of Chinese jujube(Ziziphus jujuba Mill.)fruitvascular bundle and better understand the accumulation of fruit sugar.【Methods】The distribution,micro-structure and ultrastructure of vascular bundles of Ziziphus jujuba Mill.‘Muzao'in northern Shaanxi prov-ince were studied using dye method,paraffin-section and electron microscopy technology.【Results】Theresults showed that jujube fruit vascular bundles belonged to collateral and open vascular bundle genre,and they could be divided into three distribution types:bundle in kernel,endocarp bundle and mesocarpbundle. All these bundles were developed from the 12 bundles in pedicel,2 of them developed into bun-dle in kernel,the others(10)developed into other two types of vascular bundles. Endocarp bundle andbundle in kernel mainly transported nutrition and water to seed for the stone hardening and development,while the mesocarp bundle mainly supplied for the growth of pulp tissue. The powerful phloem of vascularbundles made the transportation easier.【Conclusion】Jujube fruit vascular bundles have three distributiontypes,and different vascular bundles contribute water and nutrients to different fruit tissues. The differ-ent morphology of phloem cells and their containers at different stages may have relevance to the phloemsugar unloading pathway.