濒危红树植物红榄李开花生物学特征及繁育系统  

Flower phenology and breeding system of endangered mangrove Lumnitzera littorea(Jack.) Voigt

作　　者：张颖[1] 李燕华[1] 张晓楠[1] 杨勇[1] 

机构地区：[1]海南师范大学生命科学学院,海口571158

出　　处：《应用与环境生物学报》2017年第1期77-81,共5页Chinese Journal of Applied and Environmental Biology

基　　金：国家自然科学基金项目(31360173);有害生物控制与资源利用国家重点实验室2015开放课题(SKLBC15KF06);海南师范大学青年教师科研启动项目(QN1435)资助~~

摘　　要：为了解红树植物红榄李[Lumnitzera littorea(Jack.)Voigt]濒危的生殖生物学原因,结合野外观测,综合运用杂交指数、花粉-胚珠比、花粉活力和柱头可授性观测、人工授粉以及套袋实验等方法,对红榄李的开花生物学和繁育系统进行研究.结果表明:红榄李群体花期从1月底到8月底.单花开放过程可分为萌动、初展、盛开、凋落4个阶段.单花花期约为(12.60±0.80)d,单花序花期约持续(29.70±1.00)d,单株花期约为(115.20±6.00)d.单株平均开花数量为(9.60±0.03)万朵,单株平均开花振幅为(83.47±1.50)朵/d);红榄李的杂交指数为4,花粉胚珠比为21 649.08.实验发现红榄李繁育系统为兼性异交,传粉过程需要传粉者;红榄李的花粉生活力低于10%,花粉活力可维持至散粉后的第4天.但散粉2 d后,柱头可授性显著下降,花粉的高活力期与柱头可授期有1-2 d的重叠;在自然状况下,红榄李结果率较高但同时空胚率也高.人工辅助异株异花授粉对提高结果率和降低空胚率有明显作用.综上,红榄李"花期分散"的开花模式,花粉生活力低,自然状态下传粉效率低、胚败育严重和花果期虫害严重是导致其濒危的主要原因.Lumnitzera littorea（Jack.） Voigt is one endangered mangrove species in China. To understand the reasons of its reproductive biology, we studied its flower pheonology and breeding system by observing the outcrossing index, pollen–ovule ratio（P/O）, pollen vitality, and stigma receptivity under natural environment and artificial pollination and bagging. Generally, the L. littorea populations flowering started from the late January and ended in the late August. The flowering process of single flower could be divided into four stages as bud swelling, flower opening, full blooming and flower withering. The flowering process of single flower lasted 12.60±0.80 days, the single inflorescence lasted 29.70±1.00 days, while the individual was about 115.20±6.00 days. The mean number of flowers per plant was 96.0±0.3 thousand and the mean flowering amplitude was 83.47±1.50 per plant per day. The out-crossing index was 4, and the P/O was 21 649.08. The breeding system of L. littorea（Jack.） Voigt was outcrossing with partial self-pollination, and needing pollinators. The pollen vitality was lower than 10%. It could be maintained for 4 days after pollen dissemination. The stigma receptivity decreased significantly after pollen dissemination, and there was only a 1-2 day overlap between the pollen dehiscence and the stigma receptivity. Under natural conditions, the high empty embryo rate along with the high fruit setting rate was found. The artificial heterogenitic pollination could improve the fruit setting rate and the empty embryo rate obviously. It was concluded that the florescence mode, the low pollen viability, the low pollination efficiency, the heavy embryo abortion and the heavy damage by insects in blossom and fruit period could be the main reasons for the endangering of L. Littorea（Jack.） Voigt.

关 键 词：濒危红树植物 红榄李 开花动态 繁育系统 人工辅助授粉 濒危机制 

分 类 号：Q945[生物学—植物学]