Understanding the effects of HMW-GS and LMW-GS on processing quality using near-isogenic lines and development of functional markers for LMW-GS in wheat

摘要

HMW-GS and LMW-GS play important roles in wheat processing quality. In the present study, the relationships between glutenin subunits and processing qualities of pan bread, Chinese steamed bread and fresh white Chinese noodles were investigated in variety Aroona and its near-isogenic lines (NILs) with different high molecular weight glutenin subunits (HMW-GS) and low molecular weight glutenin subunits (LMW-GS). For dough strength-related traits such as farinograph stability and energy, 7+9,17+18, 5+10, Glu-A3b, Glu-A3d, Glu-A3f, Glu-B3b, Glu-B3g were correlated with superior dough properties. The NIL with the Glu-Al null subunit conferred a lower pan bread total score (PBTS) than the other two NILs with alleles at this locus. For dough extensibility, a significant difference was found among Glu-A3 NILs; Glu-A3e was the most inferior allele, whereas the other five Glu-A3 alleles had similar effects on R_(max), ST, %UPP and extensibility. Glu-B3g and Glu-B3b were associated with higher quality parameters than the other Glu-B3 alleles, and the Glu-B3c NIL performed the worst in PBTS, Rmax, ST, SV, %UPP and some other parameters. Five Glu-D3 alleles produced similar quality parameters except for farinograph water absorption. For Chinese steamed breadquality, Glu-B3a and Glu-B3b showed significantly better skin color. Glu-B3a exhibited a higher total score than other allelic variants. For fresh white Chinese noodles, Glu-B3a and Glu-B3d showed significantly better smoothness than the other lines, andGlu-A3b, Glu-B3g, Glu-B3h exhibited better whiteness than the others. Functional markers for LMW-GS were developed and validated on the Aroona NILs and 141 CIMMYT wheat varieties and advanced lines with different Glu-A3 and Glu-B3 alleles. These results provide very useful information for wheat quality improvement in breeding programs.