Breeding system
The GLM analysis showed that pollination treatments have significant influences on fruit set (Wald χ2 = 9.348, df = 3, P = 0.009) and seed set (Wald χ2 = 22.018, df = 3, P < 0.001) (Fig. 3). Under natural conditions, the fruit set and seed set were 65 ± 7.6 % (N = 40) and 80.4 ± 2.6 % (N = 26) respectively, which were significantly lower than hand self-pollination (87.5 ± 5.3 %, N = 40, P = 0.004, and 90 ± 0.9 %, N = 35, P < 0.001, respectively) and cross-pollination (85 ± 5.7 %, N = 40,P = 0.014, and 87.3 ± 1 %, N = 34, P = 0.002, respectively). It suggested that there was a pollen limitation under natural conditions. There was no significant difference in the fruit set between self-pollination and cross-pollination, indicating that H. mutabilis is highly self-compatible (Fig. 3). The fruit set of bagged flowers was zero (N = 40), which indicated that neither spontaneous autogamy nor apomixis occurs in this species.