[Study on breeding and pollination characteristics of Gleditsia sinensis]

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: ①G. sinensis are racemes, divided into bisexual inflorescences (only a small amount of inactive pollen) and male inflorescences (occasionally a few bisexual flowers), flowers hermaphrodite. ②Male 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. ③The 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. ④When 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. ⑤The 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.