Agronomic and quality characteristics of two new sets of Langdon durum–wild emmer wheat chromosome substitution lines

Triticum turgidum L. var. dicoccoides has been a useful source of genes for high grain protein content (GPC) in wheat. The objective of this study was to test the agronomic and quality characteristics of 23 durum Langdon–T. dicoccoides (LDN–DIC) substitutions based on T. dicoccoides accessions PI 481521 (LDN521) and PI 478742 (LDN742), with emphasis on finding new genes for high GPC. The 23 LDN–DIC substitutions and checks were grown in replicated yield trials at Fargo and Prosper, ND in 2005–2006. The lines were evaluated for grain yield, plant height, and heading date. Twelve quality traits, including GPC, were evaluated using standard methods. Potentially useful variation for thousand-kernel weight, kernel size, semolina extraction, and semolina brightness and color, was identified. Eight lines including LDN742-6B, LDN521-7B, LDN521-5B, LDN742-7A, LDN742-5B, LDN521-2A, LDN742-7B, and LDN521-1A had significantly higher GPC than LDN, suggesting that chromosomes 1A, 2A, 5B, and 7B of PI 481521 and 7A, 5B, 6B, and 7B of PI 478742 may carry high GPC genes. Using allele specific marker Xuhw89, LDN742-6B was shown to carry the same Gpc-B1 allele as in Israel A. The remaining six lines with high GPC are potential sources of new high GPC genes for durum wheat.