极晚熟杏品种冬杏光合特性研究

摘要

[Objective]The aim of this project is to study the photosynthetic characteristic of the most late-maturing Dongxing apricot,and provide theoretical basis for the study of Dongxing growth characteristics and late-maturing mechanism.[Method] Diurnal changes of PAR and PAR/CO2-Pn response curve were measured during the second slow period of fruit development (35-119 d after flowering).[Result] Dongxing diurnal changes of PAR eigenvalues showed bimodal pattern,and intercellular CO2 concentration displayed corresponding opposite law,but the change in each eigenvalue did not happen synchronically.Photosynthetic rate between the two peaks appeared at 11 and 18 o'clock.The photosynthetic " noon break" occurred at 15:00.Its LCP value was 68.33 μmol CO2/(m2 · s),LSP was 788.16 μmol CO2/(m2 · s),CCP was 135.72 μmol CO2/(m2 · s),and CSP was 1 149.38 μmol CO2/(m2 · s).Farquhar model can exactly describe its law.Pn in the diurnal change showed lower value and minor change.LCP,CCP,and Rd were much higher than the other apricot varieties.[Conclusion] Dongxing 'apricot 's diurnal changes of PAR and PAR/CO2-Pn response curve law are basically the same as other varieties,but there is a big difference between their individual characters and photosynthetic eigenvalue,and photosynthetic assimilative capacity is relatively low,which has some impact on the time of Dongxing' apricotˊS fruit growth and development.%[目的]了解极晚熟杏品种冬杏的光合特性,为进一步研究其生长发育特性及晚熟生理机制奠定基础.[方法]在冬杏果实第二次缓慢生长期(即花后35～119 d),测定其光合日变化、光响应和CO2响应曲线.[结果]冬杏的光合各特征值日变化主要表现为双峰型,胞间CO2浓度呈现相反规律,但各特征值的变化不同步.净光合速率(Pn)的两个峰值分别出现在11:00和18:00,在15:00出现光合“午休”现象.其光补偿点(LCP)为68.33 μmol CO2/(m2·s),光饱和点(LSP)为947.29 μmol CO2/(m2·s).CO2补偿点(CCP)为135.72 μmol CO2/(m2·s),CO2饱和点(CSP)为1149.38 μmol CO2/(m2·s).Farquhar模型能较好的描述其光及CO2的响应曲线.冬杏光合日变化中Pn较低且其变化幅度较小,LCP、CCP与表观暗呼吸速率(Rd)较高.[结论]冬杏的光合日变化和响应曲线规律与其它品种基本相同,但各特征值差异较大,光合同化能力相对较低,对其果实的发育期有一定的影响.