以EMS诱变创制软质小麦宁麦9号高分子量谷蛋白亚基突变体

本研究旨在创制遗传背景一致的不同高分子量谷蛋白亚基(HMW-GS)缺失系,为小麦品质研究和育种提供材料。将软质小麦品种宁麦9号,用0.4%EMS溶液处理10 000粒种子,获得3781个M1代单株,采用"半粒法"对每个株系进行SDS-PAGE鉴定,从中筛选出299个(7.91%)HMW-GS突变株,包括HMW-GS缺失和分子量突变2种类型。其中,HMW-GS缺失突变176株,突变频率为4.65%,缺失亚基涉及Ax1、Bx7、By8、Dx2和Dy12,突变频率为0.24%~3.28%;分子量突变130株,突变频率为3.44%。将突变体的具胚端种子于温室中繁殖获得M2代,再次鉴定各株系的HMW-GS,并经M3代验证,最终获得Ax1、Dx2、Bx7、By8和Dy12缺失突变体,及Ax1+By8双缺失突变体。用高效液相色谱(HPLC)分析这些突变体的谷蛋白大聚体(GMP)和谷蛋白/醇溶蛋白(GLU/GLI)比值,发现不同缺失突变体的GMP含量都有不同程度的降低,尤以Bx7亚基缺失突变体中GMP含量降幅最大,高达42%。另外,不同缺失突变体的谷蛋白总量和GLU/GLI比值也低于对照,Ax1+By8双缺失突变体的GLU/GLI比值最小。

EMS Induced HMW-GS Mutants from Soft Wheat Ningmai 9

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 10000 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 content 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.