Aims The purpose of this study is to investigate the relationship between net photosynthetic rate(Pn)and nitrogen allocation in Gossypium spp.leaves,to analyze the limiting factors that affect the improvement of photosynthetic nitrogen use efficiency(PNUE),and to reveal the photosynthetic physiological regulation mechanism of nitrogen use efficiency.Methods In this study,the gas exchange parameters,nitrogen content and proportion of different components,cell wall content per unit area(CWarea)of 16 genotypes of Gossypium spp.,including G.hirsutum,G.barbadense,G.arboreum and G.herbaceum,were measured at flowering and bolling stages.The relationship between Pn,CWarea,PNUE and nitrogen content of different components was analyzed.Important findings The results showed that when nitrogen content per unit area(Narea)was less than 3.75 g·m-2,the Pn was very significant positively correlated with Narea,When Narea exceeds this value,the Pn was not correlated with Narea,while Pn had a significant positive correlation with Ribulose-1,5-bisphosphate carboxylase/oxygenase(Rubisco)nitrogen content(Nr)and bioenergetics nitrogen content(Nb),a marginal positive correlation with light harvesting system nitrogen content(NL)in photosynthetic apparatus,indicating the nitrogen content of photosynthetic apparatus(Np)plays more important role than Narea in the photosynthetic capacity.In addition,Pn was also positively correlated with stomatal conductance(Gs).The low Pn of genotype'CHANG ZI 1 HAO'was mainly related to low Np,while low Pn of genotype'MOC-620'was mainly related to low Gs.The proportion of nitrogen components in photosynthetic apparatus was also significantly and inversely correlated with PNUE.However,the fractions of nitrogen allocated to photosynthetic apparatus components were affected by Narea and CWarea.The correlation analysis showed that the fraction of nitrogen allocation to bioenergetics(Pb)and light harvesting system(PL)was inversely correlated with Narea;the fraction of nitrogen allocation to Rubisco(Pr),PL and Pb were significantly,extremely significant and marginally negatively correlated with CWarea,respectively.The results showed that with the increase of Narea and/or CWarea,leaves tended to allocate nitrogen to non-photosynthetic apparatus,including stored nitrogen component and cell wall component.In addition,cell wall may reduce PNUE by influencing mesophyll conductance(gm).It's likely to improve the photosynthetic nitrogen use efficiency in genotype'CHANG ZI 1 HAO'and'MOC-620'by increasing the fraction of N allocation to photosynthetic apparatus and decreasing allocation to non-photosynthetic apparatus.
关键词
净光合速率/光合机构氮组分/光合氮利用效率/单位面积细胞壁含量/棉花
Key words
net photosynthetic rate/nitrogen components of photosynthetic apparatus/photosynthetic nitrogen use efficiency/cell wall content per unit area/Gossypium spp
维普
万方数据