Abstract: 【Objective】To understand the diversity origin of low-molecular-weight glutenin subunits (LMW-GS), and provide references for wheat quality improvements, the variation features of LMW-GS in the formation of wheat cultivars were characterized.【Method】With the capillary electrophoresis (CE), the seeds of three sets of hybrid materials (F5/F6), together with their corresponding parents, were used to test the variability of the LMW-GS. A series of specific primers, designed according to the genetic sequence published in GenBank, PCR amplification, gene cloning, and sequence analysis were employed to characterize the features of LMW-GSs. 【Result】The results of CE indicated that all the tested lines contained the relatively stable numbers of LMW-GS compared to the parents, while the accumulation amount of several subunits increased significantly. On the basis of the sequence analysis, all of the 54 genes (GenBank access numbers from KC222070 to KC222121, and from KC478714 to KC478715) belonged to the lmw-gs gene family because of their typical structure of LMW-GS, including the relatively conserved signal peptides, intermediate repeating regions with abundant variations and the conserved C-terminal domain. The similarity alignment between the advanced lines and their parents revealed that all the three sets of hybrid materials shared the extremely conserved sequences with their relevant parental lines and all these common sequences belonged to LMW-m subunits. The relatively conserved sequences originated from SNPs were the major proportion and both parents have been acted as their donors. It was also found the fine procedure of the extra Cys residue in the LMW-GS during the formation of wheat cultivars. What’s more, LMW-GS with 10 or 11 Cys residues was also observed in the present study. The variation of Cys residues mainly occurred in the C-terminal region Ⅱ, while only one variation in the C-terminal region Ⅲ. 【Conclusion】 During the process of wheat breeding, the m-type LMW-GS from paternal sources tend to be more conservative than other kinds of subunits, and SNPs play an important effect on the diversity of LMW-GS.

Key words: Triticum aestivum L. , low molecular weight glutenin , capillary electrophoresis , diversity