以紫薇属的紫薇(Lagerstroemia indica)品种'Bicolor'、'XTSC3'和尾叶紫薇(L.caudata)分别与散沫花属的散沫花(Lawsonia inermis)进行远缘杂交,对杂交亲本的花粉和柱头进行了扫描电镜观察,并对授粉后花粉萌发及花粉管伸长过程进行荧光显微观察.结果表明,紫薇属与散沫花属杂交存在受精前障碍.散沫花的花粉可以在紫薇品种'Bicolor'、'XTSC3'和尾叶紫薇柱头上萌发,但花粉萌发滞后,花粉管的伸长受到阻碍,难以在72～96 h内伸入子房完成受精.而散沫花作母本时,不亲和性表现为花粉与柱头间在形态上不匹配,柱头上花粉粒粘附少,柱头胼胝质的生成阻碍了花粉萌发.
In order to study the cross-compatibility between Lagerstroemia and Lawsonia, Lagerstroemia indica cultivars ' Bicolor', ' XTSC3' and Lagerstroemia caudata were used to cross with Lawsonia inermis respectively. Then pollen shape and stigma form of both parents, as well as pollen tube behavior after pollination were observed. Results indicated that the pre-fertilization barriers caused the sterility of the distant crosses between Lagerstroemia and Lawsonia. Although pollens of Lawsonia inermis were able to germinate on the stigma of any female parents that were used, pollen tube elongating was hindered, which lead to the failure of fertilization in 72 to 96 h after pollination. The incompatibility, when Lawsonia inermis acted as the female parent, was due to the mismatch of pollen shape and stigma form. Moreover, only a small amount of pollens were adhered on the stigma and the germinations were impeded by callose depositon.