Physiological characteristics of Neosinocalamus affinis and Bambusa pervariabilis × Dendrocalamopsis grandis with natural low temperature

Key words: 
• botany /
• Neosinocalamus affinis /
• hybrid bamboo （Bambusa pervariabilis × Dendrocalamopsis grandis） /
• cold tolerance

Abstract: An unusually severe snow disaster occurred in southern China in 2008，which exposed variation in bamboo species. Neosinocalamus affinis was highly tolerant to low-temperature damage，but hybrid bamboo （Bambusa pervariabilis Dendrocalamopsis grandis） died out. Why did the phenomenon occur? A study was thereupon conducted to determine the effects of natural low temperature stress on physiological characteristics to compare their chilling tolerance. Leaves of N. affinis and the hybrid bamboo were sampled in summer （22－30 ℃） and winter （－2 － 4 ℃） to study physiological characteristics，such as chlorophyll （Chl） content，membrane permeability，malondialdehyde （MDA），soluble sugar content，free proline content，and electrolyte leakage；along with superoxide dismutase （SOD），peroxidase （POD），and catalase （CAT） activities. The age of leaf samples uniforms to ensure the accuracy of experiment. The results showed that Chl contents of both bamboo species gradually decreased with decreasing temperature，whereas membrane permeability，MDA，soluble sugar content，free proline content，and electrolyte leakage increased. Also，SOD，POD，and CAT activities increased. With the same low temperature stress，MDA and electrolyte leakage in the leaves of N. affinis were lower （P＜0.01） than the hybrid bamboo，whereas free proline content，soluble sugar content，SOD，POD and CAT activities were higher （P＜0.01） than the hybrid bamboo. ［Ch，3 tab. 21 ref.］