侧柏扦插不定根发生模式研究

该研究以侧柏一年生硬枝插穗为实验材料,利用连续组织切片技术观察插穗不定根发生发育过程中的组织结构变化,分析插穗外部形态变化、不定根原基起源和不定根的形成过程,探讨侧柏插穗不定根发生模式和不定根的组织学起源。结果显示:侧柏扦插后可由愈伤组织、皮部诱导产生不定根,出现皮部生根、愈伤组织生根、愈伤组织兼具皮部生根3种类型;侧柏插穗中存在少量潜伏根原基,但插穗生根类型以诱导生根为主;不定根原基诱导产生于愈伤组织、木质部、形成层及次生韧皮部等部位。研究认为侧柏扦插生根属于多位点发生模式,不定根原基的组织学起源是愈伤组织、髓射线、射线原始细胞、尚未分化成熟的木质部细胞,通过人工诱导同时激活这些不定根起源位点能够显著提高生根率和生根质量。

Study on the Occurrence Pattern of Adventitious Roots from Hardwood Branches of Platycladus orientalis

Morphological and anatomical characteristics were observed during the formation of adventitious roots of Platycladus orientalis with paraffin method, external morphological changes, origin and formation process of adventitious roots were analyzed. We also discussed the occurrence pattern and histological origin of adventitious. The results showed that, adventitious roots protruded from callus and skin, including callus rooting type, cortex rooting type, both callus and cortex rooting type. We also found few latent root primordia in stem cutting, but most of the roots were formed on primordial induced from callus, xylem, vascular cambium and secondary phloem. Through our research, we consider the formation of adventitious root primordial of P. orientalis belong to multilocus models, and the histological origin adventitious is callus, pith ray, ray primitive cells and undifferentiated xylem cells. Simultaneous activation of these root origin sites through artificial induction can significantly improve rooting rate and rooting quality.