中文摘要：

以夏蜡梅属夏蜡梅（Sinocalycanthuschinensis）和美国蜡梅属美国蜡梅变种光叶红蜡梅（Calycanthusfloridusvat．oblongifolius）为试验材料进行属间杂交，通过荧光镜检观察花粉在柱头上的附着和萌发以及利用石蜡切片观察杂种胚发育情况，探讨其杂交障碍机制。结果表明：不论正反交，花粉均能在柱头上粘附、萌发并生长到达胚囊；以夏蜡梅为母本时父本花粉管生长进程较以光叶红蜡梅为母本时更加一致，大部分花粉管在授粉后36h到达胚囊，表明花粉萌发和花粉管生长阶段不存在杂交障碍。杂种胚发育观察结果表明，无论正反交均可以实现双受精，但结实率极低，说明属间杂交存在受精后障碍，且正反交杂交障碍机制有所不同：当以夏蜡梅为母本时，杂交障碍主要由受精后杂种胚早期的不正常解体造成；而当以光叶红蜡梅为母本时，杂交障碍主要由母本雌蕊较高比例的发育异常和杂种胚的早期败育共同引起。

英文摘要：

For an intergeneric cross between Sinocalycanthus chinensis and Calycanthusfloridus var. oblongifolius, a pollen-pistil interaction using fluorescence microscopy and hybrid embryo development through a paraffin section were conducted to reveal intergeneric cross-compatibility. Results showed that, with or without reciprocal crosses, pollen grains of male parents could adhere and further germinate on stigmas of female parents and that pollen tubes could reach the embryo sacs. The process of pollen germination and pollen tube growth was more consistent when S. chinensis was used as the female parent with most of the pollen tubes entering the embryo sacs approximately 36 h after pollination. However, with or without reciprocal crosses, the hybrid embryo development through the paraffin section caused post-fertilization barriers that led to a very low seed set. Although double fertilization was observed, most hybrid embryos aborted in the early developmental stage. The barrier mechanism between reciprocalcrosses, though, differed, with the reproductive barrier for S. chinensis x C. floridus var. oblongifolius being due to hybrid embryo abortion or degeneration in the early developmental stage, and the reproductive barrier for C. floridus var. oblongifolius x S. chinensis being due to a high percentage of abnormal megagametophytes together with hybrid embryo abortion in the early developmental stage. Thus the cross between S. chinensis and C. floridus var. oblongifolius had no barriers from pollen adherence and germination, but post-fertilization barriers meant poor seed set.