Effect Of Nitrogen Supply On Grain Weight And Quality At Different Spike Layers And Positions For Different Wheat Cultivars With Strong Gluten

This experiment was conducted in Dongwu Village,Dawenkou Town,Daiyue District,Tai’an City from 2021 to 2022.Strong gluten wheat varieties（Zhouyuan 9369,Taikemai 33,Jinan17,Jimai 20,Jimai 229 and Shiluan 02-1）were selected as test materials and two nitrogen supply were 0 kg hm^-2（N0）and 240 kg hm^-2（N240）.Effect of nitrogen supply on grain weight and quality at different spike layers and positions for different wheat cultivars with strong glutenwas systematically studied.The main research results are as follows:1.Spatial distribution of grain weight and quality traits at the spike layers and positions of different strong gluten wheatThe pattern of fertile number,grain weight and glutenin to gliadin ratio of the different strong wheat grades between the spike layers showed a decreasing trend from top to bottom,while the protein and protein fraction content showed an opposite trend,increasing from top to bottom;the aggregation index was upper middlespike layers≈lower middle spike layers>upper spike layer>lower spike layer.Comparison between different spike positions at the same spike layer shows that the lower and middle spike positions have higher fertile number and grain weight,protein content and its components than the upper spike position.Variation in grain glutenin/gliadin ratio and polymerisation index between spike positions.The upper middle spike layer and middle spike position had the best yield and quality synergy.2.Effect of nitrogen supply on fertile number and grain weight at the spike layers and positions of different varieties of strong gluten wheatNitrogen supply increased the spike number and grains per spike,and reduced the thousand grain weight of all varieties testedspike layers.Of which,Nitrogen supply mainly reduced grain weight in the lower and lower middle spike layers,while grain weight in the upper middle and middle spike layers was relatively stable and less affected by nitrogen supply;Comparison between different spike positions at the same spike layer shows that grain weight in the lower spike position was more affected by nitrogen supply,followed by the middle spike position,and less affected by nitrogen supply in the upper spike position.The effect of increasing nitrogen supply on the number of grains between spike layers of different varieties was inconsistent.The increase in nitrogen supply mainly increased the grains per spike in the upper middleandlower middle spike layers of ZY9369;the grains per spike in the upper,upper middleandlower spike layers of TKM33;the grains per spike in the upper,upper middlespike layers of JN17 and JM20;the grains per spike in the lowerandlower middlespike layers of JM229;the grains per spike in the upper,upper middleandlower middlespike layers of SL02-1.The effect of increasing nitrogen on the number of grains between spike positions did not follow a clear pattern among the six varieties tested.The increase in nitrogen supply mainly reduced the grain weight of the lower middle spike layers of ZY9369,TKM33 and SL02-1;the grain weight of the lower spike layers of JN17,JM20 and JM229.Comparing between different spike positions of the same spike layer,the increase in nitrogen supply mainly reduced the grain weight of the lower spike position of each variety tested except JM229,while JM229 mainly reduced the grain weight of the upper spike position.3.Effect of nitrogen supply on grain quality traits of different varieties of strong gluten wheat spike layers and positionsNitrogen supply increased the protein and protein fraction content of each variety,mainly increasing the lower middle spike layer,the middle spike position of ZY9369;the lower spike layer,the middle spike position of TKM33;the lower spike layer,the middle spike position of JN17 and the lower spike layer,the middle spike position of SL02-1.The effect of nitrogen supply on the grain glutenin/gliadin ratio and polymerisation index between spike layers varied considerably between varieties,the grain glutenin/gliadin ratio in the upper layer of ZY9369and TKM33,the lower middle layers of JN17,the upper and upper middle layers of SL02-1and the polymerisation index in the lower middle layers of ZY9369 and TKM33,the upper middle layers of JN17,the upper and upper middle layers of SL02-1.However,the pattern was more consistent between spike positions,with all being more responsive to nitrogen supply in the middle spike position.4.Effect of nitrogen supply on population yield and quality of strong gluten wheat varietiesNitrogen supply increased the spike number and grains per spike,and reduced the thousand grain weight of all varieties tested.Different increases in yield of different gluten wheat varieties affected by increased nitrogen supply,JM229,SL02-1,JM20,TKM33,JN17 and ZY9369 had production increases of 42.29%,42.12%,33.40%,30.05%,24.27%and 21.07%respectively.Among them,JN17 and TKM33 had the highest yields under both N0 and N240conditions,while SL02-1 had the lowest yield.Increasing the nitrogen supply increased the protein content of the test varieties and their individual protein fractions,the dough development time and dough stability time.The increase in protein content of SL02-1 and JM20 was greater under nitrogen supply,at 39.34%and29.14%.Among the six test varieties,SL02-1 and TKM33 had higher protein content,with ZY9369,TKM33 and JN17 achieving both high dough developmen and dough stability times.In a nutshell,the upper middle spike layer and middle spike position had the best yield and quality synergy.Among the six test varieties,TKM33 performs best in terms of synergy between yield and quality.The above conclusions need to be validated by repeated trials over a number of years.