| Summary: | 碩士 === 國立臺灣大學 === 園藝學研究所 === 93 === The temperature effects were studied on green bamboo (Bambusa oldhamii Munro) on its growth and shooting, and air-layering rooting in phytotron and bamboo mosaic virus-free green bamboo plantation, respectively. The growth and shooting of green bamboo layers were studied under six temperature treatments, five (D/N 35/30℃, 30/25℃, 25/20℃, 20/15℃ and 15/13℃) at phytotron and one uncontrolled at a plastic tunnel from Mar. 2004 to Jan. 2005. The results showed that the growth of culm, branch, and leaf was positively correlated with temperatures between 15/13℃ and 30/25℃. The green bamboo thrives in warm temperature. The culm height showed a S type growth curve. Branches emerged and started to grow about ten weeks after culm growth, and the growth rates were positively correlated with temperatures. No significant difference in branch number per clump and leaf number per branch were found in plants grown under temperatures of 25/20℃ and higher. The average leaf number per branch was eight. Plants under these higher temperatures had similar leaf length, leaf number per clump, and leaf area. Higher leaf growth rate was obtained at 35/30℃. The days to first shooting reduced with temperature increase. It took 45.3-48.8 days to first shooting with plants grown at 30/25℃and 35/30℃. The number of shoots increased under higher temperature. It was 12.3 shoots per clump for plants grown at 30/25℃. The highest abortion rate of shooting, 34.9% occurred at 35/30℃, and the lowest of 16.6% at 25/20℃. A curvilinear regression model (Y＝－0.000049X2＋0.0028X－0.0186，r2＝0.96) depicted the relationship between the shooting rate and mean temperatures. The largest shooting rate was reached at 28.8℃. The thermal-time was 1230 degree-day for green bamboo shooting. The chlorophyll meter reading was highest at 15/13℃ and 20/15℃. The net photosynthetic rate taken on mature leaf was the highest 6.93 μ mol m-2s-1 at 35/30℃, and plants grown at 30/25℃ and control followed the next. The results of stomatal conductance and transpiration rate followed similar trend to the net photosynthetic rate. The concentrations of glucose and starch in fresh leaves increased with temperature up to 30/25℃. Plants grown at temperature above 25/20℃ produced in a year the total dry weight of 650-736 g per clump, with proportion of 6.5-7.2% in current leaves, 7.7-9% in litter leaves, 41-44% in culm and branch, 12-13.7% in rhizome, and 28-29% in roots. Plant water content ranged between 44.3∼48.3% with the lowest in treatments of 15/13℃. The concentrations of macro-nutrients were in the order of N＞K＞Ca＞Mg＞P in leaf, K＞N＞Ca＞Mg＞P in branch & culm, and root. The leaves had the highest concentration for each elements, followed by culm ＆ branch, and roots. A linear regression model was obtained to explain the relationship between the rooting percentages of air-layering and mean temperatures (Y＝4.835X－73.51，r2＝0.90). High rooting percentages of 61∼76% were obtained from air-layering in June to September with monthly average temperatures above 26.8℃. No significant difference was found between rooting rate of air-layering and the diameter of culm, branches. The rooting rate of air-layering at proximal end of culm was 10% higher than that at distal end of culm. However, the difference diminished under warm season. The debranching treatment before air-layering could increase rooting percentage by 10% while 50% shading the branch decreased the success rate.
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