Growth and shoot emergence of green bamboo ( Bambusa oldhamii Munro) under different temperatures.

摘要

Rooted green bamboo layers were grown in phytotron for one year under six temperatures (D/N 35/30 degrees C, 30/25 degrees C, 25/20 degrees C, 20/15 degrees C, 15/13 degrees C, and control). The green bamboo thrived in warm temperatures and the growth of the culm, branch, and leaf positively correlates with temperatures between 15/13 degrees C and 30/25 degrees C. Culms reached their final length at 16-18 weeks, showing a sigmoid type growth curve. Branches emerged approximately 10 weeks after culm growth and took another 20 weeks to their maximum length. The first leaf grew at 5 days after branches initiated. No significant difference in branch number per clump and leaf number per branch are found in plants grown at temperature of 25/20 degrees C and higher. The average leaf number per branch was eight. Plants grown under three high temperature treatments had similar leaf length, leaf number per clump, and leaf area. Higher leaf growth rate was observed at 35/30 degrees C treatment and plants grown at temperature above 25/20 degrees C produced the total dry weight of 650-736 g per clump, with proportion of 6.5-7.2% in current leaves, 7.7-9.0% in litter leaves, 41-44% in culm and branch, 12.0-13.7% in rhizome, and 28-29% in roots. The litter leaves were replaced by similar amount of new leaves. The days to first shoot emergence reduced with increased temperature. It took 45.3-48.8 days to shoot emergence with plants grown at 30/25 degrees C and 35/30 degrees C. Under higher temperature the number of shoots increased with 12.3 shoots per clump for plants grown at 30/25 degrees C. The highest shoot abortion rate of 34.9% occurred at 35/30 degrees C, and the lowest rate of 16.6% occurred at 25/20 degrees C. A curvilinear regression model could depict the relationship between the shoot emergence rate and mean temperatures. The largest shoot emergence rate was reached at 28.8 degrees C.