Cytological study on stamen development of cytoplasmic male sterile line “Yunyan 85” of tobacco (Nicotiana tabacum)

The stamen abortion of male-sterile tobacco Yun-yan 85 happened from the differentiation of stamen primordial to the formation of sporogenous cell. The staminodes were visible in opening flowers,but the filaments of staminode were shortened and the anthers were abnormal without pollen or with empty pollen. The ovary of pistil in male-sterile tobacco Yunyan 85 had 3 carpels,but the counterpart of normal tobacco(maintainer line) had only 2 carpels.