sustainability Review Perennial Grain Legume Domestication Phase I: Criteria for Candidate Species Selection Brandon Schlautman 1,2,* ID , Spencer Barriball 1, Claudia Ciotir 2,3, Sterling Herron 2,3 and Allison J. Miller 2,3 1 The Land Institute, 2440 E. Water Well Rd., Salina, KS 67401, USA;
[email protected] 2 Saint Louis University Department of Biology, 1008 Spring Ave., St. Louis, MO 63110, USA;
[email protected] (C.C.);
[email protected] (S.H.);
[email protected] (A.J.M.) 3 Missouri Botanical Garden, 4500 Shaw Blvd. St. Louis, MO 63110, USA * Correspondence:
[email protected]; Tel.: +1-785-823-5376 Received: 12 February 2018; Accepted: 4 March 2018; Published: 7 March 2018 Abstract: Annual cereal and legume grain production is dependent on inorganic nitrogen (N) and other fertilizers inputs to resupply nutrients lost as harvested grain, via soil erosion/runoff, and by other natural or anthropogenic causes. Temperate-adapted perennial grain legumes, though currently non-existent, might be uniquely situated as crop plants able to provide relief from reliance on synthetic nitrogen while supplying stable yields of highly nutritious seeds in low-input agricultural ecosystems. As such, perennial grain legume breeding and domestication programs are being initiated at The Land Institute (Salina, KS, USA) and elsewhere. This review aims to facilitate the development of those programs by providing criteria for evaluating potential species and in choosing candidates most likely to be domesticated and adopted as herbaceous, perennial, temperate-adapted grain legumes. We outline specific morphological and ecophysiological traits that may influence each candidate’s agronomic potential, the quality of its seeds and the ecosystem services it can provide.