Genetic Variation of High Molecular Weight Glutenin Subunits in Wheat Accessions in China

Abstract

ABSTRACTThe high molecular weight glutenin subunits (HMW‐GS) are essential in determining bread‐making quality, and knowing their composition can help in making appropriate decisions to improve wheat (Triticum aestivum L.) quality. The HMW‐GS compositions of 189 Chinese wheat landraces (CWLs), 61 introduced lines (ILs), and 840 Chinese improved varieties (CIVs) were investigated by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) in this study. The aim was to identify novel HMW‐GS alleles and to compare the genetic diversity among the three groups. A total of 31 HMW‐GS alleles and 86 allele combinations were found in all accessions. For CWL and CIV, the predominant pattern was (null, 7+8, 2+12), with a frequency of 71.6 and 26.0%, respectively. The predominant pattern in the IL was (null, 7+9, 2+12) with a frequency of 13.6%. The IL had the largest variation and the average index of genetic variation (H). The H was 0.6117, whereas CWL and CIV had H values of 0.2275 and 0.5161, respectively. In addition, the present study showed that an increase of 7+9 and 5+10 in the CIV came from the use of foreign parents. The results revealed that the IL was an important reservoir for improving Chinese wheat‐quality characteristics such as grain protein content, hardness, and sodium dodecyl sulfate (SDS) sedimentation. Although the genetic variation in the CWL was low, it contained novel alleles (1Bx7.1* and 1By8.1*), which indicated that this group was also a potential resource for wheat‐quality improvement.