Abstract: In order to provide references to wheat breeding and high-yield cultivation， the difference of grain protein content，SDS sedimentation value and nitrogen metabolism enzyme activity in different spikelet and grain position were studied in this paper． Three kinds of wheat varieties， strong-gluten wheat Zhengmai 366，middle-gluten wheat Yumai 49-198，weak-gluten wheat Zhengmai 004 were planted in the field conditions． The result showed that grain protein content of Zhengmai 366 and Zhengmai 004 were observed the highest value in basal spikelet， followed by central spikelet， then apical spikelet． However， for Yumai 49， the grain protein content was as follow: central ＞ basal >apical． Grain protein content presented in G1 and G2 were higher significantly than G3． Therefore the G1 and G2 grain position were beneficial for improving protein content． SDS sedimentation values of the three type cultivars were observed the highest value in the middle and base positions． For Zhengmai 366，G1 grain of the middle and base position was significantly higher than other position． For the middle and weak gluten cultivar， the grain position difference presented as follow: G2 >G1 >G3． As for GS enzyme activity， the highest activity was showed in the grain of the basal spikelet of Zhengmai 366 and Yumai 49-198． But， the highest value was observed in the central spikelet grain of Zhengmai 004． As for GOGAT enzyme activity， the highest value was obtained in the basal spikelet and the lowest value was obtained in the apical spikelet． The significant correlation relationship between protein content， SDS sedimentation value，GS and GOGAT enzyme activity indicated that the improvement of GS and GOGAT activity would benefit to improve grain protein content and processing quality． Based on these results，measures of reducing florets and increasing the number of spikes could be taken to increase yield and improve quality for stronggluten and middle-gluten wheat varieties． Measures of increasing florets could be taken to increase yield and processing quality for weaken-gluten wheat variety．

Key words: Winter wheat, Spikelets and grain, Protein, Nitrogen metabolism enzyme activity

CLC Number: 

• S512.01