不同油茶品种苗对高温胁迫的生理响应及耐热性评价

Evaluation of the Physiological Response and Heat Tolerance of Seedlings of Different Camellia oleifera Cultivars to High Temperature Stress

[目的]近年来我国南方高温频发,高温环境已成为油茶生长发育的重要限制因素。为探究不同油茶品种高温胁迫的生理响应及耐热性差异,筛选出适合在高温地区种植的油茶品种。[方法]选用我国各省(区)现行的15个油茶品种为研究对象,以其3年生嫁接幼苗为试验材料,分别调查测定各油茶品种在高温胁迫(覆膜增温)下的叶片相对含水量、干物质含量、光合色素、渗透调节物质和抗氧化酶活性等12个生理生化指标,并利用主成分分析法和隶属函数法对15个品种的耐热性进行综合评价。[结果]在高温胁迫下,参试油茶品种的叶片相对含水量和干物质含量降低;光合色素含量降低,且多数存在显著差异(p<0.05);丙二醛含量、抗氧化酶活性和渗透调节物质含量均升高;隶属函数分析表明,15个油茶品种的耐热性存在差异,其强弱顺序为华金>赣州油1号>华硕>岑软2号>湘林210>赣无2>长林53号>粤韶75-2>粤韶77-1>长林4号>岑软3号>华鑫>长林40号>赣州油7号>赣石83-4。[结论]15个油茶品种中,华金、赣州油1号、华硕、岑软2号和湘林210耐热性强,适宜高温地区引种栽培。

[Objective]In recent years,high temperatures occur frequently in the south of China,and the high-temperature environment has become an important limiting factor for the growth and development of Camellia oleifera.In order to investigate the physiological response to high-temperature stress and differences in heat tolerance of different C.oleifera varieties,for selecting the the varieties suitable for planting in high-temperature areas.[Methods]Based on the 3 year-old grafted seedlings of 15 varieties currently planted in various provinces(regions)of China,the relative leaf water content,dry matter content,photosynthetic pigments,osmotic regulators and antioxidant enzyme activities of 12 physiological and biochemical indexes of the varieties under the high-temperature stress(temperature increase of the plastic film)were investigated and measured.And the principal component analysis and the affiliation function methods were used to comprehensively analyze the tolerance ability assessment.[Results]Under high temperature stress,the relative water content and dry matter content of leaves of the varieties decreased;the content of photosynthetic pigments decreased,and most of them havd significant differences(p<0.05);the content of malondialdehyde,antioxidant enzyme activity and osmotic regulating substances increased;and the analysis of the affiliation function showed that there were differences in the heat tolerance of the 15 varieties,and the variety Hwajin had the highest heat tolerance,followed by Ganzhouyou,Huashuo,Cenruan NO.2,Xianglin NO.210,Ganwu NO.2,Changlin No.53,Yueshao NO.75-2,Yueshao NO.77-1,Changlin NO.4,Cenruan NO.3,Huaxin,Changlin NO.40,and Ganzhouyou NO.7,Ganshi NO.83-4.[Conclusion]Among the 15 varieties,Huajin,Ganzhouyou NO.1,Huashuo,Cenruan NO.2,Xianglin NO.210have strong heat resistance and are suitable for planting in high-temperature areas.