Genome-wide association study of feruloyl arabinoxylan content in common wheat grain

Authors: ZHAN, S - Xinjiang Agricultural University; REN, Y - Xinjiang Agricultural University; LIU, J - Chinese Academy Of Agricultural Sciences; FUERST, E - Washington State University; XIA, X - Chinese Academy Of Agricultural Sciences; LV, W - Xinjiang Agricultural University; Morris, Craig; GENG, H - Xinjiang Agricultural University

Submitted to: Journal of Cereal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/5/2019
Publication Date: 11/12/2019
Citation: Zhan, S., Ren, Y., Liu, J., Fuerst, E.P., Xia, X., Lv, W., Morris, C.F., Geng, H.W. 2019. Genome-wide association study of feruloyl arabinoxylan content in common wheat grain. Journal of Cereal Science. 89. https://doi.org/10.1016/j.jcs.2019.06.001.
DOI: https://doi.org/10.1016/j.jcs.2019.06.001

Interpretive Summary: In this study a GWAS with 256 Chinese bread wheat varieties from two natural populations, using 18,189 and 13,198 located SNP markers from the 90 K wheat iSelect SNP array was performed. The objectives of this study were to detect elite alleles associated with FAX content base on a genome wide search in common wheat, realize the genetic bases underlying the natural variation of FAX content in wheat kernels, and discover candidate genes involved in arabinoxylan synthesis pathways based on reported wheat genomics sequencing. In this study, a significant additive effect was identified, revealing that pyramiding of favorable alleles will increase FAX content. Some varieties with high FAX content and relatively high number of favorable alleles and exceptional agronomic traits should be excellent parental lines for wheat quality breeding.

Technical Abstract: Arabinoxylan (AX) is an important component of dietary fiber, exerts significant effects on the processing quality and nutritional value of flour. The feruloyl arabinoxylan (FAX) content of endosperm is a major factor influencing the functional properties of AX. Here, genome-wide association study (GWAS) was conducted for FAX content using the high-density 90 K wheat iSelect SNP assays. FAX content was evaluated in 166 common wheat varieties from Yellow and Huai Winter Wheat Region of China (YHRVWWR) and 90 from Northern China Plain Winter Wheat Region (NWWR) in four environments. Our results showed that 83 and 33 marker-trait associations (MTAs) for FAX content were identified, explaining phenotypic variation ranging from 6.7 to 9.2% and 10.2 to 21.2% in the populations “YHRVWWR” and “NWWR”, respectively. Among them, 2 and 3 MTAs were repeatedly detected at least two environments in these populations “YHRVWWR” and “NWWR”, respectively. Five MTAs Excalibur_c35324_183, RAC875_c99286_60, BS00110201_51, BS00062894_51 and wsnp_Ex_c1050_2009301 were detected in two populations. Linear regression indicated an obvious dependence of FAX content on the number of favorable alleles, indicating that QTL gathering were be an effective approach to improve FAX content. In addition, around these significant MTAs, five candidate genes isoflavone reductase, carnitine dehydrogenase, acylamino acid releasing enzyme, glucose isomerase and GMP synthase were found to be involved in FAX biosynthesis. These results shown that SNPs and candidate genes identified on different populations, with identical evaluation methods, can be very distinct. Additionally, our study may enrich the important information for genetic improvement of wheat quality and facilitate marker-assisted selection.