Western agriculture and its most important crop plants are thought to have originated about 10,000 years ago in the Fertile Crescent, a geographical region extending from modern-day Israel, Jordan, Lebanon, and western Syria into southeastern Turkey and along the Tigris and Euphrates rivers into Iraq and Iran (Smith 1995 ; Bar-Yosef 1998 ; Diamond 1998 ; Moore, Hillman, and Legge 2000 ; Zohary and Hopf 2000 ; Gopher, Abbo, and Lev-Yadun 2002 ). Two traditional lines of evidence support that view. First, the geographical distributions of wild progenitors of modern cereal species, among them wild wheats (Triticum urartu, T. boeoticum, T. dicoccoides, Aegilops tauschii), wild barley (Hordeum spontaneum), and wild rye (S. vavilovii), intersect in this region (Nesbitt and Samuel 1996 ; Moore, Hillman, and Legge 2000 ; Zohary and Hopf 2000 ; Gopher, Abbo, and Lev-Yadun 2002 ). Second, seeds of the wild species occur in early archaeological sites of the region, followed in radiocarbon age and stratigraphic succession by the remains of domesticated forms (Moore, Hillman, and Legge 2000 ; Zohary and Hopf 2000 ; Gopher, Abbo, and Lev-Yadun 2002 ). Recently, molecular evolutionary studies have also begun to weigh heavily on this issue. Genetic identification of the natural stands from which wild crops were domesticated addresses the question of where specifically within the Fertile Crescent humans invented agriculture. The approach involves comparing wild and domesticated populations using molecular markers, which give genome-wide estimates of genetic similarity (Heun et al. 1997 ; Badr et al. 2000 ; Martin and Salamini 2000 ). One of the most promising of these techniques is amplified fragment length polymorphism (AFLP), a polymerase chain reaction (PCR)-based procedure that resolves radioactively labeled electrophoretic bands (polymorphic loci) on sequencing gels.

The origin of modern wheats involved alloploidization among related genomes. To determine if Aegilops speltoides was the donor of the B and G genomes in AABB and AAGG tetraploids, we used a 3-tiered approach. Using 70 amplified fragment length polymorphism (AFLP) loci, we sampled molecular diversity among 480 wheat lines from their natural habitats encompassing all S genome Aegilops, the putative progenitors of wheat B and G genomes. Fifty-nine Aegilops representatives for S genome diversity were compared at 375 AFLP loci with diploid, tetraploid, and 11 nulli–tetrasomic Triticum aestivum wheat lines. B genome–specific markers allowed pinning the origin of the B genome to S chromosomes of A. speltoides, while excluding other lineages. The outbreeding nature of A. speltoides influences its molecular diversity and bears upon inferences of B and G genome origins. Haplotypes at nuclear and chloroplast loci ACC1, G6PDH, GPT, PGK1, Q, VRN1, and ndhF for ∼70 Aegilops and Triticum lines (0.73 Mb sequenced) reveal both B and G genomes of polyploid wheats as unique samples of A. speltoides haplotype diversity. These have been sequestered by the AABB Triticum dicoccoides and AAGG Triticum araraticum lineages during their independent origins.

The wheat germ (embryonic axis and scutellum) represents about 2.5–3.8% of total seed weight and is an important by-product of the flour milling industry. The germ contains about 10–15% lipids, 26–35% proteins, 17% sugars, 1.5–4.5% fibre and 4% minerals, as well as significant quantities of bioactive compounds such as tocopherols [300–740 mg/kg dry matter (DM)], phytosterols (24–50 mg/kg), policosanols (10 mg/kg), carotenoids (4–38 mg/kg), thiamin (15–23 mg/kg) and riboflavin (6–10 mg/kg). Oil recovery is achieved by mechanical pressing or solvent extraction, which retrieve about 50% or 90% lipids, respectively; innovative approaches, such as supercritical carbon dioxide extraction, are also proposed. The oil is rich in triglycerides (57% of total lipids), mainly linoleic (18:2), palmitic (16:0) and oleic (18:1) acids, but relevant amounts of sterols, mono- and diglycerides, phospho- and glycolipids are present. The lypophilic antioxidants tocopherols and carotenoids are also abundant. The main by-product of oil extraction is defatted germ meal, which has high protein content (30–32%), is rich in albumin (34.5% of total protein) and globulin (15.6%), and thus presents a well-balanced amino acid profile. Its principal mineral constituents are potassium, magnesium, calcium, zinc and manganese, in decreasing order. Total flavonoid content is about 0.35 g rutin equivalent/100 g DM. The wheat germ is therefore a unique source of concentrated nutrients, highly valued as food supplement. While the oil is widely appreciated for its pharmaceutical and nutritional value, the defatted germ meal is a promising source of high-quality vegetable proteins. Better nutrient separation from the kernel and improved fractioning techniques could also provide high-purity molecules with positive health benefits.