黄槽竹及其变种自然极端低温后的生理响应特征

Physiological response characteristics of Phyllostachys aureosulcata and its varieties after natural extreme low temperature

【目的】为探究北京地区黄槽竹及其变种自然低温胁迫下的生理响应特征并对抗寒能力进行综合评价。【方法】以黄槽竹、金镶玉竹、黄秆京竹3个竹种为研究对象,分析其自然极端低温后的叶绿素含量、渗透调节物质、抗氧化系统指标、内源激素特征,并采用熵权TOPSIS法对抗寒性进行综合评价。【结果】黄槽竹叶绿素含量均高于其他两个竹种。黄秆京竹丙二醛(MDA)含量最高,但抗氧化物酶(SOD、POD、CAT)活性低于其他两个竹种。黄秆京竹幼壮竹叶片中可溶性糖、可溶性蛋白含量均显著高于其他两个竹种。金镶玉竹随着年龄的增大,其叶绿素含量、SOD、POD活性显著降低,渗透物质含量变化差异不显著(P>0.05)。黄秆京竹幼壮竹的3种渗透物质含量显著高于老竹,黄槽竹两个年龄阶段间抗氧化系统指标差异达显著水平(P<0.05)。3个竹种的ABA/GA_(3)比值大小排序为:金镶玉竹、黄槽竹、黄秆京竹。方差分析及相关性分析表明叶绿素a、叶绿素b、叶绿素总量、可溶性糖、可溶性蛋白、MDA、POD、CAT、SOD在竹种间差异显著(P<0.05),各指标间均存在不同程度的相关性。【结论】竹种是影响黄槽竹及其变种抗寒性的主要因子,竹种与竹龄的交互作用次之。基于熵权TOPSIS综合评价法,MDA含量在抗寒指标中所占的权重最大(35.44%),其次为POD、SOD活性。针对11个指标进行TOPSIS评价得出金镶玉竹抗寒能力最强。ABA/GA_(3)的比值越大竹种抗寒性越强,表明激素在植物体内的作用相互关联并不孤立。

[Objective]This study aimed to investigate the physiological responses of Phyllostachys aureosulcata and its varieties to natural low temperatures in Beijing and to make a comprehensive evaluation of their cold tolerance.[Method]Phyllostachys aureosulcata and its varieties(Phyllostachys aureosulcata f.spectabilis,Phyllostachys aureosulcata f.aureocarlis)were used to analyze their chlorophyll content,osmoregulatory substances,antioxidant system indicators and endogenous hormone characteristics,the entropy-weighted TOPSIS method was used to comprehensively evaluate the cold tolerance of the three varieties.[Result]The chlorophyll content of Phyllostachys aureosulcata was higher than that of its varieties.Phyllostachys aureosulcata f.aureocarlis had the highest malondialdehyde(MDA)content,but its antioxidant enzyme(SOD,POD,CAT)activities were lower than those of the other two varieties.The soluble sugar and soluble protein contents in young bamboo leaves were significantly higher than those of the other two varieties.The chlorophyll content,the activity of SOD and POD of Phyllostachys aureosulcata f.spectabilis decreased significantly with increasing age,and the changes in osmotic substances content were not significantly different(P>0.05).The content of the three osmotic substances was significantly higher in young Phyllostachys aureosulcata f.aureocarlis than in the old ones,and the difference in the indexes of the antioxidant system between the two age stages of Phyllostachys aureosulcata reached a significant level(P<0.05).The ABA/GA_(3)ratios of the three varieties were ranked as follows:Phyllostachys aureosulcata f.spectabilis,Phyllostachys aureosulcata,Phyllostachys aureosulcata f.aureocarlis.ANOVA and correlation analysis showed that chlorophyll a,chlorophyll b,total chlorophyll,soluble sugar,soluble protein,MDA,POD,CAT,and SOD differed significantly(P<0.05)among varieties,and all indicators were correlated with each other to different extents.[Conclusion]Variety influenced the cold hardiness of Phyllostachys aureosulcata and its varieties most,followed by the interaction between variety and age.Based on the entropy-weighted TOPSIS comprehensive evaluation method,MDA content accounted for the greatest weight(35.44%)in the cold hardiness indicators,followed by the activities of POD and SOD.Evaluation of the 11 indicators showed that Phyllostachys aureosulcata f.aureocarlis was the most cold resistant variety.The ratio of ABA/GA_(3)indicates that the hormones may regulate cold tolerance in bamboo by crosstalk.