紫薇品种与尾叶紫薇种间杂交亲和性研究

Compatibility of Interspecific Crosses between Lagerstroemia indica Cultivars and Lagerstroemia caudata

通过杂交结果率比较和荧光显微观察对5个紫薇（Lagerstroemia indica）品种与尾叶紫薇（L.caudata）杂交亲和性进行研究。结果显示：（1）以紫薇品种作母本与尾叶紫薇进行杂交（正交）,‘白云映霞’结果率最高,达36.6%,而‘粉蝴蝶’×尾叶紫薇未结果。以尾叶紫薇作母本时（反交）,各紫薇品种均可结果,结果率为16.6%-51.8%。（2）荧光观察发现,尾叶紫薇花粉在紫薇雌蕊上萌发和生长受到一定的阻碍,表现为授粉后柱头乳突细胞产生大量胼胝质反应,花粉管生长过程中出现较多胼胝质栓塞等;而紫薇的花粉在授粉1 h后即可在尾叶紫薇柱头上萌发,8 h花粉管伸入子房,10 h完成受精。研究表明,各正交组合的亲和性有明显差异,存在受精前障碍,而反交组合亲和性较好,不存在受精前障碍。

The interspecific compatibility between five Lagerstroemia indica cultivars and L.caudata was assessed by comparing the fruit and seed production,seed germination,and pollen tube growth following controlled cross-pollinations.Results showed that L.indica ＇Baiyunyingxia＇had higher percent pod set（36.6%） than did the other crosses,when L.indica cultivars were used as famale parents（original cross）.There was no pod harvested from ＇Fenhudie＇.All combinations could bear fruits with the percentage of pod set ranging from 16.6%～51.8%,when L.caudata was used as the female parent（reciprocal cross）.The callose response was appeared both on stigma papilla cells and in pollen tubes after original cross,which indicated the delay of pollen germination and elongation of L.caudata.Pollens from L.indica cultivars,however,could germinate at 1 h after pollination.Pollen tubes reached ovary at 8 h and finished fertilization 10 h after hybridization.Compatibility of original crosses was obviously different,which was probably due to pre-fertilization barriers.The reciprocal crosses shown good interspecific compatibility.