外源水杨酸对浙江楠幼苗抗寒生理的影响

Effect of exogenous salicylic acid on the cold resistance physiology of Phoebe chekiangensis

为探究低温条件下外源水杨酸(salicylic acid,SA)对浙江楠(Phoebe chekiangensis)幼苗抗寒生理的影响,以期为浙江楠的保护、引种、栽培和开发利用提供科学依据。设置5个SA浓度(0、0.1、0.5、1.0、2.0 mmol·L^(-1))对浙江楠1年生容器苗进行连续3 d的叶面喷施处理,随后利用人工气候室模拟0℃低温,再进行连续7 d的低温胁迫处理,以20℃常温为对照(CK),测定相对电导率(REC)、叶绿素(Chl)含量、丙二醛(MDA)含量、过氧化物酶(POD)活性、超氧化物歧化酶(SOD)活性、可溶性蛋白(SP)含量、可溶性糖(SS)含量、脯氨酸(Pro)含量等生理指标,对浙江楠相关抗寒生理指标进行了相关性和主成分分析。结果表明,适宜浓度的外源SA可以有效缓解REC、MDA含量的上升及Chl含量的下降,促进抗氧化酶活性增加及渗透调节物质积累,减轻低温造成的胁迫伤害。主成分分析结果表明,外源SA预处理在0℃胁迫下能有效提高浙江楠幼苗的抗寒能力,其中1 mmol·L^(-1)的SA处理具有最大缓解效应。

To investigate the regulatory effect of exogenous salicylic acid(SA)on the cold resistance physiology of Phoebe chekiangensis under low temperature conditions,in order to provide scientific basis for the protection,introduction,cultivation,and development of P.chekiangensis.Five SA concentrations(0,0.1,0.5,1.0,2.0 mmol·L^(-1))were set to spray the annual container seedlings of P.chekiangensis on the leaf surface for three consecutive days.Then,the climatron was used to simulate the low temperature at 0℃,and then the low temperature stress treatment was carried out for seven consecutive days.The relative conductivity(REC),chlorophyll content(Chl),Malondialdehyde(MDA),peroxidase(POD),Superoxide dismutase(SOD),soluble protein(SP),soluble sugar(SS),proline(Pro)and other physiological indicators.Then the correlation and PCA of physiological indexes of cold resistant of P.chekiangensis were carried out.The results indicate that exogenous SA at appropriate concentrations can effectively alleviate the upward trend of REC and MDA content,as well as the downward trend of Chl,increase the activity and accumulation of antioxidant enzyme and osmoregulation substances,and alleviate stress damage caused by low temperature.The results of principal component analysis showed that exogenous SA pretreatment could effectively improve the cold resistance of P.chekiangensis under 0℃stress,with a SA treatment of 1 mmol·L^(-1)having the greatest alleviating effect.