An overview of the role of lucerne (Medicago sativa L.) in pastoral agriculture

Pastoral agriculture is unique among the world’s agricultural production systems. Lucerne (also known as alfalfa), Medicago sativa L. subsp. sativa, has a long history of playing a very important role in pastoral agriculture. That role is expanding outside traditional hay and grazing production systems into sprouts for salads, nutritional supplements, and bioenergy feedstock. It is also the forage legume of choice for delivery of new traits via biotechnologies. The use of biotechnologies in lucerne improvement will cause re-examination of research methods and will require unique collaborations that are both interdisciplinary and even cross-institutional. The Consortium for Alfalfa Improvement (CAI) is discussed as a model for this type of collaboration. Breeding programs will continue development of cultivars with the proper fall (autumn) dormancy, a broad genetic base for pest resistance, increased local adaptation, persistence, and yield, while also adding new complex traits to these base traits. Increasing nutritional quality via down-regulation of lignin genes and increasing persistence via grazing tolerance, drought tolerance, and tolerance to acid, aluminium-toxic soils are discussed as examples of the potential impacts and challenges surrounding incorporation of complex traits. However, it is the potential for lucerne to become a major part of tropical or subtropical production systems or even an important adjunct to overcome deficiencies in the widely used perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.) temperate systems that begs further attention.