新疆特有濒危植物雪白睡莲繁殖生物学研究

Aims Nymphaea candida, an endangered species endemic to Xinjiang and classified as a National Class II Protected Wild Plant in China, faces a high risk of extinction, necessitating immediate conservation measures. This study aims to reveal its reproductive characteristics and explore factors associated with its endangered status from a reproductive biology perspective.Methods This study systematically examined the flowering phenology, floral morphology, breeding system, pollination process, and seed germination characteristics of N. candida in natural populations.Important findings The flowering period spanned from May to September, with individual flowers persisting for approximately 4 d, while stigmatic receptivity was limited to 1-2 d. Pollinators were primarily hoverflies (Syrphidae), but their visitation rates were low and further reduced by adverse weather conditions. Experimental data indicated a mixed breeding system in N. candida, predominantly outcrossing but self-compatible, with pollinator dependency for successful reproduction. Seed viability was determined to be (45.33 ± 4.29)%, yet germination rates under natural conditions were significantly lower (2.67 ± 1.63)% due to physical dormancy imposed by seed coat barriers. Reproductive limitations in N. candida arose from its floral traits, pollination challenges (e.g., limited pollinator availability and low visitation rates), and low seed viability. Environmental stressors (e.g., frequent rainfall) exacerbated pollination constraints. In unpredictable pollination environments, N. candida relied on autonomous self-pollination, which may result in inbreeding depression, thereby escalating its endangerment risk.