高寒区玉米叶片光合参数日变化及其与环境因子关系OA北大核心CSTPCD

The characteristics of photosynthetic parameters of maize leaves in alpine region were in-vestigated.Field experiments were carried out in Nandao village,Songjiang town,Antu county,using Longping 702 maize varieties as materials,net photosynthetic rate(Pn),stomatal conductance(Gs),transpiration rate(Tr),intercellular CO2 concentration(Ci),photosynthetically active radiation(PAR),air temperature(T),and air relative humidity(RH)of maize leaves were determined using a Li-6400 photosynthetic apparatus during the extraction and male-spraying period.The relationship between photosynthetic parameters and environmental factors was analyzed.The results showed that:the changes of leaf Pn and Tr of maize in alpine region were double peak curve,the peak of Pn appeared at 10:00 and 14:00,respectively.Tr peaks were around 10:00 and 13:00,respectively.Gs maximum reached at 10:00,followed by a downward trend.Ci decreased first and then increased.At 6:00-10:00,Pn showed an extremely significantly positive correlation,a significantly positive correlation,and an extremely significantly negative correlation with PAR,T,and RH,respectively(r=0.927,r=0.574,r=-0.765);At 14:00-18:00,the correlation between Pn and PAR,T,and RH was r=0.921,r=0.553,r=-0.712,respectively;At 06:00-10:00,Gs showed an extremely significantly positive cor-relation with PAR(r=0.772)and a significantlt negative correlation with RH(r=-0.550);At 10:00-14:00,Gs showed a significantly positive correlation with PAR(r=0.545)and a positive correlation with RH(r=0.482);At 06:00-10:00,Tr showed an extremely significantly positive correlation with PAR(r=0.953),and an extremely significantly negative correlation with RH(r=-0.857).At 06:00-10:00,Ci showed an extremely significantly negative correlation with PAR(r=-0.655).The results showed that low air temperature and photosynthetically active radiation and high air relative humid-ity are the main factors limiting the production of photosynthetic materials in maize.