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ARS Home » Plains Area » Fargo, North Dakota » Research » Publications at this Location » Publication #305917

Title: Analysis of agronomic and domestication traits in a durum x cultivated emmer wheat population using a high-density single nucleotide polymorphism-based linkage map

Author
item Faris, Justin
item Zhang, Qijun - North Dakota State University
item Chao, Shiaoman
item Zhang, Zengcui
item Xu, Steven

Submitted to: Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/15/2014
Publication Date: 9/4/2014
Publication URL: http://handle.nal.usda.gov/10113/60596
Citation: Faris, J.D., Zhang, Q., Chao, S., Zhang, Z., Xu, S.S. 2014. Analysis of agronomic and domestication traits in a durum x cultivated emmer wheat population using a high-density single nucleotide polymorphism-based linkage map. Theoretical and Applied Genetics. 127:2333-2348.

Interpretive Summary: Cultivated emmer wheat is one of the eight founder crops that spawned the Agricultural Revolution about 10,000 years ago. Cultivated emmer has non-free-threshing seed and a somewhat fragile rachis, but mutations in genes governing these and other agronomic traits occurred that led to the formation of today's fully domesticated durum wheat. Here, we used genetic and statistical analyses to identify and characterize domestication and agronomic traits that differ between cultivated emmer and durum wheat by analyzing the progeny from a cross between the two. The major domestication gene Q had profound effects on several domestication and agronomic traits as expected. The cultivated emmer parent produced more kernels than durum, and the durum parent contributed higher kernel weight, which led to the identification of some progeny that had higher yields than either parent by inheriting the most desirable genes. Threshability was governed not only by the Q gene, but other genes as well indicating that mutations multiple threshability genes occurred during the transition of cultivated emmer to the fully domesticated tetraploid. These results not only shed light on the events that shaped wheat domestication, but also demonstrate that cultivated emmer is a useful source of genetic variation for the enhancement of durum varieties.

Technical Abstract: Cultivated emmer wheat (Triticum turgidum ssp. dicoccum) is tetraploid and considered one of the eight founder crops that spawned the Agricultural Revolution about 10,000 years ago. Cultivated emmer has non-free-threshing seed and a somewhat fragile rachis, but mutations in genes governing these and other agronomic traits occurred that led to the formation of today's fully domesticated durum wheat (T. turgidum ssp. durum). Here, we evaluated a population of recombinant inbred lines (RILs) derived from a cross between a cultivated emmer accession and a durum wheat variety. A high-density single nucleotide polymorphism (SNP)-based genetic linkage map consisting of 2,593 markers was developed for the identification of quantitative trait loci. The major domestication gene Q had profound effects on spike length and compactness, rachis fragility, and threshability as expected. The cultivated emmer parent contributed increased spikelets per spike, and the durum parent contributed higher kernel weight, which led to the identification of some RILs that had significantly higher grain weight per spike than either parent. Threshability was governed not only by the Q locus, but other loci as well including Tg-B1 on chromosome 2B and a putative Tg-A1 locus on chromosome 2A indicating that mutations in the Tg loci occurred during the transition of cultivated emmer to the fully domesticated tetraploid. These results not only shed light on the events that shaped wheat domestication, but also demonstrate that cultivated emmer is a useful source of genetic variation for the enhancement of durum varieties.