关键词: 桃, 果实, 维管束, 中果皮, 内果皮

Abstract: In order to understand the distribution and structure of vascular tissue in the peach fruit, observation of the branches system and distribution of vascular bundleswas taken with the normal paraffin section and peach (Prunus persica‘Okubao’) fruitwas used asmaterial. The results showed that: Vascular bundles in peach fruit can be divided into three types, main vascular bundle, branch vascular bundle and fibrous vascular bundle. Main vascular bundles include embryo vascular bundle, endocarp vascular bundle and mesocarp
vascular bundle (ventral bundle and dorsal bundle, and vascular bundles on endocarp from pedicel). Their functions are that transport nutrition to the seed, endocarp and the mesocarp respectively. Embryo vascular bundle has developed phloem and tertiary structure; Vascular bundles with developed phloem are annularly distributed in the endocarp; Ventral bundle and dorsal bundle are thick, both of them have a majority of branches and developed phloem and xylem. Branch vascular bundles and fibrous vascular bundlesmainly distribute in the mesocarp. The cavity is observed in phloem of fibrous vascular bundle in the mesocarp and it enlarges
with the fruit growth. The structures of vascular bundles accommodate to their functions. It can be speculated that seed and endocarp mostly need organic nutrition and the mesocarp needs organic nutrition, mineral nutri2
tion and water.

Key words: peach, fruit, vascular bundle, mesocarp, endocarp