早实核桃‘农核1号’的光合特性

【目的】了解早实核桃新品种‘农核1号’的光合特性,为该品种优质高效栽培提供参考。【方法】以早实核桃‘农核1号’为试材,采用Li 6400测定叶片净光合速率(P_n)、蒸腾速率(T_r)、气孔导度(G_s)、胞间CO_2浓度(C_i)、水分利用效率(WUE)、气孔限制值(L_s)及主要环境因子的日变化,分析各指标间的关系。【结果】‘农核1号’叶片P_n日变化呈单峰曲线,最高峰出现在9:00,峰值达15.67 μmol/(m^2·s)。11:00—19:00,P_n降低主要受非气孔限制因素的影响。一天当中P_n及其他光合参数在不同时段存在一定差异。相关分析结果表明,P_n与T_r在13:00—19:00呈极显著正相关;P_n与G_s在各时段均呈极显著正相关;P_n与C_i在7:00—9:00呈极显著负相关,在9:00—13:00呈不显著正相关,在13:00—19:00呈不显著负相关。光响应曲线分析结果表明,‘农核1号’叶片的LCP较低且LSP较高,分别为53.84和752.16 μmol/(m^2·s),说明‘农核1号’对弱光照较为敏感,适应性强。通径分析结果表明,7:00—9:00主要环境因子PAR对‘农核1号’叶片P_n的影响大于G_s,两者均表现正效应;9:00—13:00各指标按照对叶片P_n的影响由高到低排序依次为C_i、WUE、G_s,C_i表现负效应,G_s和WUE表现正效应;13:00—16:00主要光合参数G_s对叶片P_n的影响大于C_i,G_s表现正效应,C_i表现负效应;16:00—19:00主要光合参数WUE对叶片P_n的影响大于T_r,两者均表现正效应。【结论】在生产上引种和栽培‘农核1号’时,应注意扩大株行距,保持通风透光,从而提高光合产物的积累。

Photosynthetic characteristics in early bearing‘Nonghe No.1’walnut

【Objective】To learn photosynthetic characteristics and to provide some references for high quality and efficient cultivation of a new precocious walnut cultivar of‘Nonghe No.1’.【Method】Using early bearing walnut‘Nonghe No.1’as material,daily changes of net photosynthetic rate(Pn),transpiration rate(Tr),stomatal conductance(Gs),intercellular CO2 concentration(Ci),water use efficiency(WUE),and stomatal limit value(Ls)in leaves,as well as main environmental factors,were determined by Li-6400,and their relationships were analyzed.【Result】Diurnal variation of Pn in‘Nonghe No.1’leaves shows a single-peak curve,and the highest peak appears at 9:00,and the peak value is 15.67μmol/(m2·s).Pn is decreased by non-stomatal limitation factors from 11:00 to 19:00.There are some differences between Pn and other photosynthetic parameters at different time of the day.The results of correlation analysis show that Pn shows a significantly positive correlation with Tr from 13:00 to 19:00.Pn shows a significantly positive correlation with Gs during the day.Pn shows a significantly negative correlation with Ci from 7:00 to 9:00,a no significant positive correlation with Ci from 9:00 to 13:00,and a no significant negative correlation with Ci from 13:00 to 19:00.The results of light response curve analysis show that,LCP in‘Nonghe No.1’leaves is lower and LSP is higher,which are 53.84 and 752.16μmol/(m2·s),respectively,which indicates that‘Nonghe No.1’is sensitive to weak light and has strong adaptability.The results of path analysis show that main environmental factor PAR has a higher influence on Pn in‘Nonghe No.1’leaves than Gs from 7:00 to 9:00,and both of them show positive effects.Based on effects on Pn in leaves from high to low,order of the indexes is Ci,WUE,Gs from 9:00 to 13:00,Ci shows a negative effect,and WUE and Gs show positive effects.From 13:00 to 16:00,main photosynthetic parameter Gs has a higher effect on Pn in leaves than Ci,Cs shows a positive effect,and Ci shows a negative effect.From 16:00 to 19:00,main photosynthetic parameter WUE has a higher effect on Pn in leaves than Tr,and both of them show positive effects.【Conclusion】In induction and cutivation of‘Nonghe No.1’,more attention should be paid to expanding plant spacing and keeping ventilation and light transmission,so as to increase accumulation of photosynthetic products.