Abstract:

In order to understand the biological characteristics and seedling breeding condition of extremely small populations of Betula fujianensis, natural forests of Betula fujianensis in Luobuyan Natural Reserve of Sanming in Fujian Province were taken as the study area, and the reproductive phenology of Betula fujianensis were observed for 3 years. Meanwhile, the germination rate of Betula fujianensis seeds at different harvest time under different environmental conditions were studied to obtain the best harvest time of Betula fujianensis, and to provide a theoretical basis for population expanding propagation and immigration protection. The results are as follows. (1) Betula fujianensis is monoecious and heterogamy deciduous species with an annual leaf growth cycle about 240 days. Its male inflorescence growth cycle is as long as 310 days, while the female inflorescence grows more shortly, within 60 days from germination to abscission, and the fruit cluster maturity stage is about 7 days. (2) The seeds harvesting time has significantly effects on seed quality and germination rate of Betula fujianensis. Being soaked for 5 hours at room temperature is beneficial to improve the germination rate of seeds harvested at mid-maturity stage (April 30). (3) The germination rate of seeds under cold storage for 2 months is significantly higher than that under room temperature storage and frozen storage. The seeds of Betula fujianensis are unsuitable to be preserved at room temperature, and should be sowed with mining or stored in cold or frozen conditions for a short time. (4) The mixture of sand and red soil by 3:1 is the most suitable substrate for Betula fujianensis seeding bed. The quality and germination rate of Betula fujianensis seeds are affected by harvest time, and the survival rate of seedlings is greatly affected by soaking treatment and substrate condition.

Key words: Betula fujianensis, plant phenology, seeds, germination rate, environmental factors