Flowering dynamics and dichogamy characteristics of Manglietia glauca for two-time flower opening and closure.
To study the influence of flowering dynamics and dichogamy characteristics on sexual reproduction of Manglietia glauca in the introduced area of Pingxiang, Guangxi, three stands of M. glauca were selected as the study area. Based on the flowering phenology and flowering dynamics, pollen and stigma viability in different flowering stages were tested. Results showed that (1) M. glauca started to bloom in late January, reached full bloom in late March, and lasted to early May. M. glauca occasionally bloomed twice a year with the second flowering phase lasting from the middle of October to early December. (2) Due to temperature difference in different flowering stage, the duration of each phase in flowering process was different, appeared different two-time flower opening and closure pattern. (3) Manglietia glauca showed dichogamy and protogyny in its flowering process with the pistil located in the upper stamens to avoid the possibility of self-pollination that could occur both in time and space. M. glauca also bloomed for centralized synchronization in single plant level. When flower pollen was released during the first round of flowering, pistil viability in the second round of flowering was stronger. The time of strongest expression for both male and female sexuality overlapped from 1-6 h, and this provided opportunity for successful pollination. (4) After artificial xenogamy, geitonogamy, and self-pollination, the fruits and seeds could be set with the pollination success rate of xenogamy being highest (68%). The pollination success rate was lowest (40%) in the initial flowering period with the lowest temperatures, but the pollination success rate was higher in the transition period (65%) and bloom stage (68%) with higher temperatures. The high pollination success rate of xenogamy indicated that M. glauca had priority for out-crossing but was self-compatible to some degree, and the pollination success rate of the initial flowering period, the transition period, and the bloom stage indicated that a high temperature was more beneficial to fertilization and embryo development than a low temperature.