O维管结构异常Abnormal vascular bundle 药隔维管分化简单(Abnormal vessel in,维管束 鞘细胞大vascular bundle sheath cells expand O绒毡层结构与功能异常The structure and function of tapetum are abnormal. 增生延缓退化proliferate and delay to degenerate 2525 ○维管结构异常 Abnormal vascular bundle 药隔维管分化简单(Abnormal vessel in ，维管束 鞘细胞大 vascular bundle sheath cells expand ○绒毡层结构与功能异常 The structure and function of tapetum are abnormal. 增生延缓退化 proliferate and delay to degenerate