Aegilops

In spite of more than 200 years of botanical exploration of the Orient, resulting in many herbaria and germplasm collections, sequence data, and transferred alleles, our knowledge on the genus Aegilops is far from complete. Several aspects concerning the genus Aegilops L. will be reviewed in this chapter. We consider 23 annual species and follow in their classification the monographs of Hammer (Kulturpflanze 28:33–180, 1980a; Feddes Rep 91:225–258, 1980b) and van Slageren (Wild wheats: a monograph of Aegilops L. and Amblyopyrum (Jaub. & Spach) Eig (Poaceae). Agricultural University Papers, Wageningen, Netherlands, 1994). We show that Aegilops species have been closely involved in wheat evolution, played a major role in wheat domestication, and will play a critical role in future wheat improvement. We show that the keys to obtain deeper insights to Aegilops genetic diversity, Aegilops–Triticum molecular biological relationships, and to harvest and preserve suitable alleles for future wheat improvement are (1) a comprehensive germplasm collection covering the whole distribution area of each species; (2) the comparison of several accessions for each species considering all ploidy levels; (3) the use of new molecular fingerprinting techniques and the access to high-throughput sequencing technologies; (4) the improvement of analytical methods capable of treating various issues based on mathematical and statistical models, and (5) archeological excavation campaigns should also consider studies on Aegilops species. We urgently need detailed studies for each Aegilops species dealing with natural distribution range, ecology, soil, geomorphology, molecular resources, and genome sequences. There is an urgent need for an active in situ conservation to protect Aegilops species in their natural habitats.