Identification of a 6P chromosome segment from Agropyron cristatum that increases anthocyanin and hydrolyzed amino acid contents in wheat

Highlights 1 1. Two novel black-grained wheat lines (PB31334 and PB31340) were identified among the wheat— Agropyron cristatum derivatives and exhibited significantly greater amounts of anthocyanin than common wheat did. 2. The 6P chromosome from A. cristatum controlled the black grain trait, and the gene was localized to 6PL (bin 6–17). 3. The 6PL (bin 6–17) region significantly increased the anthocyanin content without negatively affecting yield traits, making it a valuable resource for improving wheat nutrition. Wheat is a major staple crop worldwide, and with the ongoing changes in dietary patterns, the demand for improved nutritional quality in wheat has been increasing. Black-grained wheat is a promising germplasm rich in nutrients. Agropyron cristatum (2 n = 4 x = 28, PPPP) is a wild relative of wheat that carries several desirable genes for genetic improvement. Here, we identified black-grained lines PB31334 and PB31340 from wheat— A. cristatum derivatives, which exhibited significantly higher anthocyanin content and possibly increased amino acid content compared with common wheat. These lines were identified as wheat— A. cristatum 6P (6A) disomic substitution lines, with the alien chromosome 6P from A. cristatum responsible for the black grain trait, as revealed by genetic analysis of four segregated populations created by crossing PB31334 and PB31340 with Fukuho and Xinong979. Additionally, three lines were identified, including telosomic lines carrying the short arm (6PS) and the long arm (6PL) of alien chromosome 6P, as well as a 6PL-deletion line lacking a partial segment of the long arm (bin 6–17). The line with 6PL displayed the black grain trait, whereas the other two did not. The gene was localized to the 6PL (bin 6–17) region without affecting the grain number per spike or thousand-grain weight. Notably, the total anthocyanin content increased in 6PL telosomic line and was positively correlated with grain coloration. The newly identified 6PL chromosomal region is a valuable resource rich in anthocyanins, offering a promising avenue for increasing the nutritional content of wheat.