外源物质处理对高温胁迫下苹果果实抗氧化能力的影响

高温胁迫下,果实表皮组织抗氧化代谢变化的总趋势是O2-和MDA含量升高,当胁迫在一定范围内,SOD和POD活性上升;超过一定限度,SOD和POD活性下降。外源自由基产生剂能够增加内源O2-的含量,同时极显著提高SOD的活性。试验结果表明,在45℃温度胁迫下,果实表皮组织O2-含量增加14.52％~61.70％;SOD活性提高1.07~1.66倍。不同种类外源活性氧产生剂对内源O2-含量的影响效能有所不同。碱性二亚硫酸钠可直接产生O2-,所以诱导内源O2-合成的效果更大一些。不同种类外源物质均可显著或极显著提高果实表皮组织SOD和POD活性,提高果实的抗热性。

Effect of Exogenous Agents on Apple Fruit Resistance to Oxidative Stress under High Temperature Condition

A tendency towards fruit resistance to oxidative stress was found that the contents of O2- and MDA increased during high temperature treatment and the activities of SOD and POD rose within a certain range and decreased under severer stress. Spraying with exogenous agents could significantly raise O2- contentand SOD activities. In the present test, the O2- content in fruit rose by 14.52% - 61.70% and SOD activity by 1.07-1.66 times, respectively. Effect of active oxygen agents on enhancing synthesis of O2- content in fruit varied with different types of formulations, with a significant influence exerted by Na2S204 which could release O2- directly. In addition, SA, SBN and Vc could increase SOD and POD activities in fruit effectively, thus resulting in an accumulation of system acquired resistance (SAR) to heat.