摘要
巨龙竹 (Dendrocalamus sinicus Chia et J.L.Su)分布于云南南部 ,其直径粗近 30 cm,竹高近 30 m,是世界上已知最粗大的巨型丛生竹种 ,具有极大的开发利用价值。本文指出巨龙竹存在2个明显不同的变异类型 ,即竹秆弯曲、歪扭 ,竹节变形、缩短、斜交的“歪脚龙竹”和节间正常、节部平滑 ,竹秆通直、分枝高而少的通直巨龙竹。经初步分析后认为 ,造成这种差异的主要原因是遗传因素 ,因此发展巨龙竹时一定要选择优良种源 ,以免给生产造成损失。通过对巨龙竹在原产区不同气候条件下的生长情况尤其是越冬情况的观察分析 ,并结合已有的引种资料 ,将巨龙竹在我国的气候适宜性分为最适宜区、适宜区和不适宜区。其主要气象指标是 :最适宜区最冷月平均气温大于 13℃ ,全年日最低气温小于 0℃的日数不超过 1天 ,全年无霜 ,巨龙竹冬季无低温危害 ,直径最粗可达到 2 5cm以上 ;适宜区最冷月平均气温大于 10℃ ,全年日最低气温小于 0℃的日数不超过 5天 ,年平均有霜日数小于 12天 ,巨龙竹冬季一般无低温危害 ,极端年分有一定程度的冻害发生 ,但对生产没有太大的影响 ,巨龙竹直径可达到 2 0~ 2 2 cm左右 ;不适宜区最冷月平均气温小于 10℃ ,年平均有霜日数大于 12天 ,全年日最低气温小于 0℃的日数超过 5天 。
Dendrocalamus sinicus Chia et J.L.Su originally grows in the south parts of Yunnan Province.It is the largest sympodial bamboo species in the world,it approaches to 30cm in diameter and 30m in height.It finds that there are two visiblly different variet types under this species. For the first one, its culms are winding, crooked with abnormal, shortened and oblique internodes. The culms of the second type are straight,smooth,their branches only occur in high parts above the ground. It is mainly caused by the genetic factors. Comparing their growth state in different climate conditions in their native regions,especially over wintering state,and in consideration of their introduction information available,it could be devided into:optimal growing region,suitable growing region and unsuitable growing region. In optimal region,mean air temperature of the coldest month is higher than 13℃, days of daily minimum temperature below 0℃ each year is less than 1 day, no frost days in the whole year, culm might be thicker than 25 cm. In suitable region, mean air temperature of the coldest month is higher than 10℃, days of daily minimum temperature below 0℃ each year is less than 5 days, mean annual frost days is less than 12 days, without chilling injury in winter usually. A slight freezing injury could be happened in exceptional year. The bamboo may grow up to 20~22cm in diameter or more. In unsuitable region, mean air temperature of the coldest month is less than 10℃, days of daily minimum temperature below 0℃ all the year is more than 5 days and mean annual frost days is more than l2 days. The huge bamboo grows badly or can not survive in winter in this case, therefore loses the value of plantation.
出处
《竹子研究汇刊》
2001年第1期19-26,共8页
Journal of Bamboo Research
基金
云南省重点基金项目! (1999C0 0 0 6 Z)
国家教委高等学校骨干教师资助计划