Mechanisms of improving nitrogen uptake,utilization and grain yield of wheat population with high radiation use efficiency
[Objectives]We constructed different types of radiation use efficient populations through the plant densities of wheat,and compared their N accumulation and transport characteristics before anthesis and the N accumulation after anthesis,to provide a theoretical base for improving wheat yield through efficient radiation use efficiency(RUE).[Methods]Field trials were conducted in Suixi and Mengcheng counties of Anhui Province in 2018-2019,the cultivar"An 1302"with strong tillering ability and"Wankenmai 0622"with weak tillering ability were employed as the test materials.Four plant densities:180×104 plants/hm2(D1),240×104 plants/hm2(D2),300×104 plants/hm2(D3),and 360×104 plants/hm2(D4)were set up for the investigation of yield,and the interception rate,amount,and photosynthetic conversion efficiency of active radiation at milk-ripening stage.According to these data,the wheat population was divided into high,moderate and low radiation use efficient types,denoted as H-,M-,and L-RUE,respectively.The N accumulation and translocation during anthesis stage,and the N accumulation and leaf area index at milk-ripening stage were compared among the three population types.[Results]Cultivar,density and their interaction significantly affected the RUE and grain yield.The RUE and grain yield of H-RUE population were 1.4%and 9.7 t/hm2,which were higher than those of M-and L-RUE by 5%and 14%,1%and 5%,respectively.The interception rate at anthesis and milk-ripe stages,and the interception amount of available radiation from anthesis to milk-ripe stages were not significantly different among the three population types,but the photosynthetic conversion efficiency of H-RUE was 2.34 g/MJ,which was higher than that of M-and L-RUE population.The H-RUE population had a higher leaf area index at anthesis(7.24)and milk-ripe stages(4.53),and higher N accumulation in stem&leaf sheath(63.9 kg/hm2),leaves(79.5 kg/hm2),and per unit leaf area(143.78 μg/cm2)at anthesis,compared to the other population types.In addition,H-RUE population and the individual stem had similar translocation rate of N at pre-anthesis stage with the M-and L-RUE populations and the individual stems,but had significantly higher N translocation amount due to their higher N accumulation amount.The leaf area index of H-RUE population was significantly higher than the M-and L-RUE populations at anthesis and milk-ripening stage as well.[Conclusions]The wheat population with high radiation use efficiency could accumulate more N in stems&leaf sheaths,and leaves,and has higher N accumulation amount per unit leaf area before anthesis stage,in spite of higher translocation amount of N,the N accumulation in the vegetative organs is higher than those in the moderate and low radiation use efficiency populations,so the population maintains high leaf area index at anthesis and milk-ripening stage,which is inductive to the radiation conversion and the formation of yield.
wheatradiation utilization efficiencyradiation resources utilizationnitrogen uptakeleaf area indexyield
万方数据
维普
