关键词: 种子, 幼苗, 存活率, 动态生命表, 鹅掌楸, 黄瓜, 超微结构, 光合作用, CO₂加富, 水氮耦合

Abstract: The emergence and survival rates of Liriodendron chinense in a seedling nursery were investigated, and dynamic life table was complied based on the periodical observation data. The result shows that the emergence rates of four kinds of provenance were quite low (1.64～3.05%), much lower than those of their full-seeds. The emergence rate of natural provenance was higher than that of cultivated provenance, but the rate of seedlings to full-seeds for the natural provenance was lower than that for the cultivated one. After a growth season, the rate of seedling survival to emergence was 16～27%, whereas that of the later generation of mating by Huangshan and Lusha provenance was 60%, significantly higher than that of their parents and other provenance. The size of seeds had no direct effect on seedling emergence and survival. The effect of genetic and environmental factors on seedling survival was also discussed. It is suggested that the low fitness of seeds and seedlings is one of the important factors causing the species being endangered.

Key words: Seed, Seedling, Survival rate, Dynamic life table, Liriodendron chinense, cucumber, CO₂ enrichment, water-nitrogen coupling, ultrastructure, photosynthesis