Quality traits. High grain protein content
Gpc-B1 gene from Triticum turgidum ssp. dicoccoides. Stripe rust resistance gene Yr36
Grain protein content (GPC) is one of the most important quality factors for pasta and bread wheats. Breeding for an increase in GPC is difficult because the genetic variation for this character is small compared to variations caused by the environment, besides there is a negative correlation between GPC and grain yield.
The high grain protein content (Gpc-B1) gene transferred from Triticum turgidum ssp. dicoccoides into durum wheat is a valuable resource for increasing GPC (1, 2). Preliminary results suggest that in different backgrounds this gene has none or minimal effects on grain yield, protein quality, plant height or heading date (2, 4). The Gpc-B1 gene was also transferred to hexaploid backgrounds. One of the hexaploid lines obtained was Glupro, which is the donor parent in several backcrossing programs within the IFAFS project. Different mapping experiments indicated that the location of the QTL for the transferred Gpc-B1 gene in both, pasta and bread wheat, is on chromosome arm 6BS, between the Nor and the centromere (3, 5, 6).
The stripe rust resistance gene Yr36 is closely linked to the Gpc locus, and the same markers used for tagging Gpc-B1 can be used for Yr36.
For breeding purposes there are two categories of markers, those for the Gpc-B1 gene itself (or Yr36) and those for reducing the linkage drag. RFLP, microsatellite and sequence specific PCR markers are available (see methods).
One of the first sources for transferring the Gpc-B1 gene into tetraploid durum wheats was Dic6B. Now two more durum lines including the Gpc-B1 gene are available: UC1113, UC1114 (seeds of these lines can be requested to Jorge Dubcovsky).
In the case of hexaploid wheats, Glupro (HRS) is a frequently used germplasm, which can be obtained from Mohamed Mergoum. Other available lines are: ND683, that can also be requested from M. Mergoum, Yecora rojo-Gpc-B1 (HRS), Anza-Gpc-B1 (HRS) and Kern-Gpc-B1 (HRS), this lines are available from Jorge Dubcovsky.
1. Chromosomal location of genes for grain protein content of wild tetraploid wheat. Joppa LR, Cantrell RG. In: Crop Science, 1990, 30(5):1059-1064 [abstract]
2. Grain protein determinants of the Langdon durum-dicoccoides chromosome substitution lines. Deckard EL, Joppa LR, Hammond JJ, Hareland GA. In: Crop Science, 1996, 36(6):1513-1516. [abstract]
3. Mapping gene(s) for grain protein in tetraploid wheat (Triticum turgidum L.) using a population of recombinant inbred chromosome lines. Joppa LR, Du C, Hart GE, Hareland GA. In: Crop Science, 1997, 37(5):1586-1589 [abstract]
4. Quality characteristics of durum wheat lines deriving high protein from a Triticum dicoccoides (6b) substitution. Kovacs MIP, Howes NK, Clarke JM, Leisle D. In: Journal of Cereal Science, 1998, 27(1):47-51 [abstract]
5. RFLP markers associated with high grain protein from Triticum turgidum L. var. dicoccoides introgressed into hard red spring wheat. Mesfin A, Frohberg RC, Anderson JA. In: Crop Science, 1999, 39(2):508-513. [abstract]
6. Development of PCR-based markers for a high grain protein content gene from Triticum turgidum ssp. dicoccoides transferred to bread wheat. Khan IA, Procunier JD, Humphreys DG, Tranquilli G, Schlatter AR, Marcucci-Poltri S, Frohberg R, Dubcovsky J. In: Crop Science, 2000, 40(2):518-524. [abstract]
7. Microcolinearity between a 2-cM region encompassing the grain protein content locus Gpc-6B1 on wheat chromosome 6B and a 350-kb region on rice chromosome 2. Distelfeld A, Uauy C, Olmos S, Schlatter AR, Dubcovsky J, Fahima T. In: Functional & Integrative Genomics, 2004, 4: 59-66. [abstract]
8. Physical map of the wheat high-grain protein content gene Gpc-B1 and development of a high-throughput molecular marker. Distelfeld A, Uauy C, Fahima T, Dubcovsky J. In: New Phytologist, 2006, 169:753-763 [abstract]