| In order to investigate the effects of different nitrogen fertilizer application rates on the starch physicochemical properties and structure of wheat grain, and to analyse the reasons for the differences in the starch physicochemical properties, a strong-gluten variety Fengdecunmai 5 and a medium-gluten variety Bainong 207 were selected as the experimental materials, and set up four nitrogen application rates of 0, 180, 240, and 300 kg·hm-2 noted as N0, N180, N240, N300 respectively. Starch physicochemical properties and structural characteristics under different nitrogen fertiliser application rates were determined. The results showed that with the increase of nitrogen application rate, the peak viscosity and swelling potential of the two varieties wheat were first rising and then falling, the peak temperature, enthalpy, content of branched starch B2 and B3 long chains, relative crystallinity, degree of surface ordering, number proportion of large starch granules all showed a trend of first declining and then rising. Fengdecunmai 5 and Bainong 207 all the extreme values were N240 and N180 treatment respectively. Compared with the N0 treatment, the N240 treatment of Fengdecunmai 5 and the N180 treatment of Bainong 207 showed an average increase in swelling potential of 36.74% and 7.23%, an average decrease in enthalpy of 18.94% and 27.43%, an average decrease in relative crystallinity of 16.29% and 9.82%, and an average decrease in the degree of order of the starch surface layer of 5.09% and 4.21%, respectively. In conclusion, the moderate application of nitrogen fertilizer can improve the starch physicochemical properties and structure of wheat grain. |
基本信息
