萘乙酸对太子参光合特性的影响  

Effects of Naphthylacetic Acid on Photosynthetic Characteristics of Pseudostellaria heterophylla

作　　者：时蕾[1] 袁婷婷 许中秋 谢寅峰[1] SHI Lei;YUAN Tingting;XU Zhongqiu;XIE Yinfeng(Co-Innovation Center for Sustainable Forestry in Southern China,College of Biology and Environment,Nanjing Forestry University,Nanjing 210037,China)

机构地区：[1]南京林业大学南方现代林业协同创新中心/生物与环境学院,江苏南京210037

出　　处：《江西农业大学学报》2021年第2期253-260,共8页Acta Agriculturae Universitatis Jiangxiensis

基　　金：国家科技支撑计划项目(2015BAD04B02);江苏高校优势学科建设工程资助项目(PAPD)。

摘　　要：【目的】探究外源萘乙酸对太子参光合作用的调控及其作用机制,为太子参高效栽培提供理论依据和技术途径。【方法】采用不同质量浓度α-萘乙酸(0,10,20,50 mg/L)叶面喷施处理,测定其对光合日变化气体交换参数和叶绿素荧光参数的影响。【结果】(1)5月下旬,对照太子参净光合速率(Pn)日变化呈双峰型曲线,有明显的“午休”现象,且“午休”期间光合能力的下降主要受非气孔因素影响;不同质量浓度萘乙酸处理虽未改变双峰型变化趋势,但均不同程度地提高了P_(n)日均值及峰值,缓解“午休”现象;以10 mg/L处理效果最佳,P_(n)日均值及12:00谷值分别比对照增加41.57%和22.52%,均差异显著(P<0.05)。(2)与对照相比,10 mg/L萘乙酸处理组在60 d内显著促进太子参叶片总叶绿素含量、荧光参数PSⅡ潜在光化学效率(F_(v)/F_(m))、有效光化学效率(F_(v)'/F_(m)')、实际光化学效率(ηΦPSⅡ)、电子传递速率(CETR)和光化学淬灭(C_(PQC))(P<0.05),同时降低非光化学淬灭(CNPQ),即萘乙酸处理能增强光合系统对光能的吸收、转换与利用效率,缓解过剩激发能所导致的热耗散的增强。(3)灰色关联分析表明,大气温度是制约净光合能力的主要环境因素,适当浓度的萘乙酸处理能够降低其与温度、光强等环境因子的关联度。相关性分析表明,Pn与叶绿素含量、G_(s)、C_(P_(QC))、ηΦPSⅡ呈显著正相关,而与C_(i)、C_(NPQ)成显著负相关。【结论】适宜质量浓度萘乙酸处理能够通过改善气孔与非气孔限制有效提升太子参叶片的光合性能,增强其对高温和强光环境的适应能力,提高光化学效率是其缓解光抑制的主要机制。[Objective]The regulation effect and its mechanism of exogenous naphthalene acetic acid on photosynthetic characteristics of Pseudostellaria heterophylla were studied in order to provide a theoretical basis for efficient cultivation of P.heterophylla.[Method]Different concentrations of α-naphthalene acetic acid(0,10,20,50 mg/L)were sprayed on leaves to determine the effects of naphthalene acetic acid on diurnal variation of photosynthesis,gas exchange parameters and chlorophyll fluorescence parameters.[Result]The results showed that:(1)In late May,the diurnal changes of the net photosynthetic rate(P_(n))of the control P.heterophyl⁃la showed a bimodal curve,there was an obvious“noon break”phenomenon,and the decline of photosynthetic capacity during the“noon break”was mainly affected by non-stomatal factors;different concentrations ofα-naphthalene acetic acid treatment did not change the bimodal trend,however,the daily average and peak values of Pn were increased to varying degrees,alleviating the“noon break”phenomenon;the effect of treatment with 10 mg/Lα-naphthalene acetic acid was the best,and the daily average value of Pn and the valley value at 12:00 were respectively compared with the control,it increased by 41.57%and 22.52%,both of which were significantly different(P<0.05).(2)Compared with the control,10 mg/Lα-naphthalene acetic acid treatment significantly promoted total chlorophyll content,potential photochemical efficiency(F_(v)/F_(m)),effective photochemical efficiency(F_(v)'/F_(m)'),actual photochemical efficiency(ηΦPSⅡ),electron transfer rate(CETR)and photochemical quenching(C_(PQC))of P.heterophylla leaves within 60 days(P<0.05),at the same time,the non photochemical quenching(CNPQ)was decreased,that is,theα-naphthalene acetic acid treatment could enhance the absorption,conversion and utilization efficiency of light energy by the photosynthetic system,and alleviate the increase in heat dissipation caused by excess excitation energy(.3)Grey correlation analysis showed that net p

关 键 词：太子参 萘乙酸 光合日变化 叶绿素荧光 

分 类 号：S718[农业科学—林学]