| Summary: | 碩士 === 國立臺灣大學 === 森林學系 === 85 === This study investigated the changes in the morphology and
physiology of Pasania ternaticupula seedlings by treating
germinated seedlings continuously with different levels of
nitrogen fertilizers and light intensities, and examined the
outplanting performance of those nursery seedling stocks. The
results showed that height growth, collar diameter, dry weights
of shoots and roots, Dickson quality index, the numbers of
stomata per unit leaf area and ratio of chlorophyll a and b of
seedlings increased when the relative light intensity was
increased in the greenhouse. Relative light intensities of 26%
and 16% full daylight were more effective than a relative light
intensity of 4% full daylight. However, the increases of dry
weight of leaf, shoot-root ratio, leaf numbers, leaf area, leaf
area ratio, special leaf area and total chlorophyll content in
leaf were measured under a relative light intensity of 4% full
daylight and were significantly different as compared to a
relative light intensity of 26% full daylight. In the nitrogen
fertilizer experiment, growth height, collar diameter, dry
weight of seedling, leaf numbers, leaf area and ratio of
chlorophyll a and b of seedlings were increased following an
increase in nitrogen fertilizer quantity. The analysis of 20
amino acids from leaves revealed that there was no significant
difference in concentrations of these amino acids among the four
nitrogen fertilizer treatments. However, concentrations of each
of the 20 amino acids increased when light intensity decreased.
According to a correlation analysis, seedling growth after
outplanting was affected by both nitrogen fertilizers and light
intensities. Furthermore, correlation analysis between seedling
growth and parameters indicated that seedling growth was
positively correlated with the Dickson quality index, but
negatively correlated with special leaf area and tryptophan.
In summary, the treatments with relative light intensity of 26%
or 16% full daylight, and nitrogen concentrations of 300 or
400kg per ha had better seedling growth.
|
|---|
