自然低温对慈竹和撑绿杂交竹生理特性的影响

为探讨慈竹Neosinocalamus affinis耐寒机制,分析了慈竹与撑绿杂交竹Bambusa pervariab ilis×De ndroc alamopsis grandis在夏季常温(22～30℃)和冬季低温(-2～4℃)生理指标的变化情况.结果表明:随着气温的降低,慈竹和撑绿杂交竹叶片叶绿素质量分数降低；可溶性糖、游离脯氨酸、丙二醛质量分数以及电解质渗漏率显著升高(P＜0.01)；超氧化物歧化酶、过氧化物酶和过氧化氢酶活性显著上升(P＜0.01).在相同低温下,慈竹游离脯氨酸、可溶性糖、叶绿素、超氧化物歧化酶、过氧化物酶和过氧化氢酶活性显著高于撑绿杂交竹;而丙二醛以及电解质渗漏率显著低于撑绿杂交竹.慈竹在自然低温条件下通过生理机能的改变主动适应低温环境,提高其耐寒性.慈竹抗寒性强于撑绿杂交竹.

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

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（P0.01） than the hybrid bamboo,whereas free proline content,soluble sugar content,SOD,POD and CAT activities were higher（P0.01） than the hybrid bamboo.