DEVELOPMENT

Desert King was developed at the University of California wheat breeding program by wheat breeders Dr. Jorge Dubcovsky and Oswaldo Chicaiza and lab assistant Xiaoqin Zhang. ‘Desert King-High Protein’(henceforth, DK-HP) showed a significantly higher grain protein concentration than the original variety ‘Desert King’ (8 to 10% increase) and improved pasta quality parameters as determined at the California Wheat Commission Quality Laboratory. Funding for this project came from the University of California Discovery grant, the California Wheat Commission and the California Crop Improvement Association.

BREEDING HISTORY & DESCRIPTION

Desert King-High Protein is a short-stature spring durum variety with erect leaves and excellent lodging resistance. This variety was developed by five backcrosses of the high grain protein content gene Gpc-B1 from wild wheat into Desert King followed by agronomic selection. The original Desert King is a widely grown Desert Durum variety developed by the University of California Wheat Breeding program. It has very high yield potential, low black tip incidence, and excellent pasta quality. The Gpc-B1 gene present in wild wheat is functional whereas the form present in Desert King and other commercial durum cultivars is not functional. The replacement of the non-functional copy by the functional one, increases grain protein content by approximately 10% and accelerates grain maturity 5-8 days. The Gpc-B1 gene, discovered at Dr. J Dubcovsky laboratory in 2006 (Science 2006, 314:1298-1300), is very close to an additional gene for stripe rust resistance designated Yr36. The two genes were transferred together using molecular markers flanking both genes, increasing grain protein content and stripe rust resistance in DK-HP simultaneously.

ADAPTATION

DK-HP was tested in the Durum Wheat Elite Trials in 2008 and 2009 and in Regional Trials in 2009 and 2010 under the UC identification number UC1627. DK-HP combines a high yield potential, good pasta quality, and resistance to the major wheat pathogens found in California. Its primary use is for pasta production. DK-HP performs well agronomically in all areas where it has been evaluated in California. DK-HP is well suited for the San Joaquin and Imperial Valley, the main durum producing areas in California, but has also the potential to expand the durum growing area in California to the Sacramento Valley, an area were previous varieties were unable to reach the high grain protein content levels required for high-quality pasta varieties.

PEST & DISEASE RESISTANCE

DK-HP was resistant to the current races of leaf rust, stripe rust, black point, barley yellow dwarf virus.

AVERAGE YIELD DATA

The faster maturity of DK-HP has the potential to accelerate harvesting 5 to 8 days relative to Desert King but also results in a shorter grain filling period and an average yield reduction of 3-4% relative to Desert King (based on 5 field trials). This slight reduction in yield is compensated by an 8-10% increase in grain protein content, resulting in a net increase in total harvested Nitrogen (Table 1). Therefore, DKHP is preferred to Desert King when higher levels of grain protein are desired, for use in blends to rich grain protein targets, or to grow high quality durum in the Sacramento Valley. Often there is a graph or table here.