● 显微结构的变化 O小孢子发育异常（减数分裂后）Microspores develop abnormally ▲单核早中期败育Microspores degenerates at early and middle microspore stage →不具外壁或外壁异常Pollens with non- outwall→典败Typical abortive:大麦(barley)、豌 豆(pea)、水稻(rice) 34 34 ●显微结构的变化 ○小孢子发育异常（减数分裂后）Microspores develop abnormally ▲单核早中期败育 Microspores degenerates at early and middle microspore stage →不具外壁或外壁异常 Pollens with non￾outwall →典败Typical abortive ：大麦(barley)、豌 豆(pea)、水稻(rice)