皂荚繁育系统与传粉特性研究

Study on breeding and pollination characteristics of Gleditsia sinensis

为研究皂荚的繁育系统与传粉特性。观察记录花的发育和传粉过程,采用TTC法和联苯胺-过氧化氢法分别测定花粉活力和柱头可授性,并运用OCI,P/O比率和人工授粉检测其繁育系统,用荧光显微镜观察花粉管生长。结果表明:(1)皂荚为总状花序,分为两性花序(仅有少量无活力花粉)和雄花序(偶有少数两性花),花杂性。(2)雄花在花开后4 h花粉活力最强;两性花柱头可授性在开花后1 h最高,此时授粉最好。(3)花粉管在两性花半开时少数萌发,开放时花粉管数量明显增多并大幅伸长变粗,开败时到达子房甚至进入胚珠,完成受精。(4)皂荚的OCI=4,P/O=11 684,结合套袋实验结果,判定其繁育系统为兼性异交,需要传粉者;存在孤雌生殖。(5)皂荚传粉特性为风媒传粉和虫媒传粉,传粉昆虫初步确定为蜜蜂。上述研究为杂交创制皂荚新种质奠定理论技术基础。

To study the breeding system and pollination characteristics of Gleditsia sinensis,we observed the development of flower development and the processing of pollination,and determined the pollen viability and stigma acceptability by TTC and benzidine-hydrogen peroxide method and detected its breeding system using OCI value,P/O ratio and artificial pollination. The results showed that:(1) G. sinensis are racemes,divided into bisexual inflorescences( only a small amount of inactive pollen) and male inflorescences( occasionally a few bisexual flowers),flowers hermaphrodite.(2)Male flowers had the strongest pollen activity 4 h after flowering;the stigma receptivity of bisexual was the highest at 1 h after flowering,and pollination was the best in this time.(3)The pollen tube had a few elongation when the bisexual flower is half-opened. The number of pollen tube and length significantly increased when blooming. The flower reaches the ovary and even enters the ovule to complete the fertilization.(4) When the OCI = 4 and P/O = 11 684,it means that the breeding system was facultative,outcrossing,and requiring pollinators based on the results of the bagging experiment. There was parthenogenesis.(5) The characteristics of saponin pollination were wind pollination and insect vector pollination,and pollinators were initially identified as Apis mellifera ligustica. All these results provides a theoretical and technical foundation for the new germplasm of G. sinensis.