Abstract:

Field investigations and artificial pollination experiments were conducted to explore the flowering characteristics and breeding system of the remnant Myricaria laxiflora (Franch.) P. Y. Zhang et Y. J. Zhang population in Dianjun Yanzhiba in Yichang, downstream of the Three Gorges Dam. Results showed that: (1) The flowering period of the M. laxiflora remnant population extended from September to April, with a peak blooming period from October to November and a single flower lifespan of two to seven days. The temporal and spatial overlap of the female and stamen structures within a single flower facilitated self-pollination. (2) The out-crossing index (OCI) was 2 and the pollen-ovule (P/O) ratio was 329, suggesting that M. laxiflora operates under a facultative autogamy (xenogamy) system. (3) Artificial pollination experiments demonstrated that while M. laxiflora exhibited partial self-compatibility, the rate of seed setting from cross-pollination significantly exceeded that of self-pollination. The study suggested that a high rate of self-crossing within the remnant population. Thus, conservation measures should be implemented to reduce human disturbance and protect the habitat and genetic diversity of the remnant populations should be subjected to ongoing surveillance.