Flowering dynamics and pollination characteristics of Lysimachia davurica

ObjectiveLysimachia davurica is an important traditional Chinese medicine. The study of flowering dynamics and pollination characteristics can provide a theoretical basis for the protection of planting resources, cross breeding and application of medicinal reproduction.

MethodThe floral syndrome and breeding characteristics of L. davurica were investigated by observing flower morphology and flowering dynamics, testing pollen vigor and stigma acceptability, calculating outcrossing index and pollen-ovule ratio with pollination and bagging treatment.

ResultThe results showed that L. davurica was a bisexual and panicles flower. Single flower period was generally 4 days and the duration of an individual inflorescence was about 35−50 days. There were two flowering peaks in the whole flowering process. The first and second peak occurred at 6−10th and 15th day after the beginning of flowering, respectively. Pistil matured earlier than stamen in the same flower. Stigma receptivity and pollen vigor increased first and then decreased with the prolongation of flowering time. Stigma maintained high receptivity at 2 hours to 5 days after flowering. The activity index of pollen reached the maximum at 0.5−1 hours and was inactivated at 1.5−2 hours after flowering. The P/O (pollen/ovule) ratio and OCI (outcrossing index) value of L. davurica were 878.7 and 4, respectively. According to the results of P/O ratio, OCI and bagging test, the breeding characteristics of L. davurica were confirmed to be facultative outcrossing and self-compatible. Sphaerophoria macrogaster and Apis cerana were effective pollinators (the flower visiting insects). Flower visiting peak period ranged from 9:00 to 11:00 am. It can visit many flowers continuously. S. macrogaster stayed in each flower for about 16−28 seconds and A. cerana for about 9−17 seconds.

ConclusionThe florescence of L. davurica was long and the florescence of single plant lasted for 35−50 days. There were two flowering peaks in the whole flowering process. The pistil matured earlier than the stamen and the time of pollen keeping vitality was short. The pollination characteristic was self-compatible and facultative outcrossing. The pollination of L. davurica required pollinators.