显微结构的变化 X 胼胝质沉积和降解异常 Callus is abnormal in acumuration and degeneration 提早解离Microspore separates earlier than normality 绒毡层过度膨胀引起Tapetum expands abnormally 推迟降解Callus degenerates more lately than usually 绒毡层过早解体，酶不能合成Tapetum degenerated earlier than usually 2727 ●显微结构的变化 ○胼胝质沉积和降解异常 Callus is abnormal in acumuration and degeneration 提早解离 Microspore separates earlier than normality ： 绒毡层过度膨胀引起 Tapetum expands abnormally 推迟降解 Callus degenerates more lately than usually ： 绒毡层过早解体，酶不能合成 Tapetum degenerated earlier than usually