Responses of seed viability and germination in four Caragana species when buried in soil under snow cover in Xinjiang

The viability and germination capacity of seeds after storage depends on the environment and seed characteristics during storage. Seasonal snow cover affects seed viability and germination ability in soil by supplementing water sources and regulating near-surface temperature and humidity. In this study, the viability and germination ability of seeds of wild Caragana soongorica Grub., C. tekesiensis Y. Z. Zhao & D. W. Zhou, C. acanthophylla Kom., and C. roborovskyi Kom. from Xinjiang were studied through simulated snow cover and indoor germination experiments after nearly 5 months storage under snow. Compared to their respective viabilities with no snow cover, results demonstrated a 36% decline in seed viability for C. soongorica and a 3% decline in seed viability for C. acanthophylla and C. roborovskyi under snow cover, while C. tekesiensis remained unaffected. The germination rates of the four Caragana species under snow cover ranged from 37% to 84%, which was not significantly different from that without snow cover. Under snow cover, some C. acanthophylla and C. roborovskyi seeds germinated early in the field. Thus, it is recommended to sow C. acanthophylla and C. roborovskyi before snowfall in early winter, while C. soongorica and C. tekesiensis can be sown in the spring of the following year.