深山含笑二次开合开花动态与雌雄异熟特征

Flowering dynamics and dichogamy characteristics of Michelia maudiae for tow-time flower opening and closure

对深山含笑(Michelia maudiae)的花部特征、开花动态、开花物候、花粉活力和柱头可授性进行研究。结果表明:①深山含笑花期为2月下旬至4月中上旬,表现为集中开花模式;②单花开放时间固定,且有二次开合现象,开放过程可分为露白、首次开花期、闭合期和二次展开期共4个时期;③深山含笑在单株水平上为同步集中式开花,单花花期约为7~12 d,单株花期约为20~38 d;④深山含笑柱头在开花前1 d已具有可授性,开放当天可授性最高,随后可授性迅速下降,而雄蕊在开花第2 d开始散粉,花粉活力最高时期为开花第3 d,为(64.6±6.1)%;(5)深山含笑为雌雄异熟且雌蕊先熟,并且雌雄特征有重叠表达阶段,这样不仅可有效减少自交,又可支持自交,足以保证生殖成功。

The flower characteristics,flowering dynamic and flowering phenology,pollen and stigma viability in different flowering stages of Michelia maudiae were studied. Results showed that:①the flowers were produced in a massflowering pattern from late February to early mid-April;②the flowering process of a single flower could be divided into four periods(petal whitening,the first flowering,the closing period and the second unfolding period),and the flowering time in one day was fixed,and two-time opening-closure flowering was observed;③the flowering phenology manifested some synchronization among single flower and individual,the flowering process of single flower lasted 7-12 days,and anthesis of individual lasted about 20-38 days;④the stigma had receptivity the day before the bloom and had the highest receptivity on the day of opening and then decreased rapidly,and stamen began to disperse pollens on the 2 nd day after flowering,and the highest pollen activity was(64. 6±6. 1)% on the 3 rd day after flowering;(5)Michelia maudiae showed dichogamy and protogyny in its flowering process,and there were the overlapping expression stage for both male and female sexuality,which can not only effectively reduce self-pollination,but also support self-pollination,to ensure the success of reproduction.