EMS Induced HMW-GS Mutants from Soft Wheat Ningmai 9

Abstract

The objective of this study was to create a series of deletion lines of high molecular weight-glutenin subunit(HMW-GS) in similar backgrounds for wheat quality research and breeding. A total of 3781 M1 plants of Ningmai 9(a soft wheat cultivar) were obtained from 10 000 seeds induced by 0.4% ethyl methane sulfonate(EMS). The HMW-GS compositions of these plants were identified via SDS-PAGE using half seed. Two hundred and ninety-nine lines with a mutation percentage of 7.91% were found to be HMW-GS mutants, including HMW-GS deletion and molecular weight mutation. Among them, 176 lines were HMW-GS deletion mutants, with a mutation percentage of 4.65% containing subunits Ax1, Bx7, By8, Dx2, and Dy12, with the mutation percentages ranging from 0.24% to 3.28%. The mutants of molecular weight were 130 lines with a mutation percentage of 3.44%. Each of the half M1 seed with embryo was used to produce M2 generation in greenhouse. Homozygous deletion lines of HMW-GS Ax1, Dx2, Bx7, By8, Dy12, and Ax1+ By8 were detected using SDS-PAGE and confirmed in M3 generation. The content of glutenin macropolymer(GMP) and the ratio of glutenin-to-gliadin(GLU/GLI) ratio were determined using high performance liquid chromatography(HPLC). The results showed that all the deletion mutants had lower GMP contents than Ningmai 9, particularly, the Bx7 deletion line had the reduced GMP content of 42%. The GLU/GLI ratio of the deletion lines was also smaller than that of Ningmai 9, and the lowest GLU/GLI ratio was found in Ax1+ By8 deletion line.