Eragrostis Wolf.

MAHMOUD, Z; ECHENIQUE, V.; DIAZ, M; PESSINO, S.; SORRELLS, M.

Wild Crop Relatives: Genomic & Breeding Resources

Springer

Lugar: New York, Tokio; Año: 2009;

Eragrostis is the largest genus within subfamily Chloridoideae of the Poaceae.  The first description and naming of the genus was made by Wolf (1776) on a specimen of Eragrostis minor. Although it is not clear why Wolf selected this name, ‘love grass’ is the accepted name for the genus (from eros, love and agrostis, grass). Today about 350 species have been described in the genus. Most species occupy open habitats with poor soils and many occur in ruderal sites (Van den Borre and Watson 1994). Their distribution extends across wide altitudinal and moisture gradients from pluvial to xeric habitats. Most of the species (50%) appear to be native of Africa (Cufodontis 1974). Fifty five species are native in Australia (Lazarides 1997), 25 in United States and Canada and 36 in Mexico (Peterson and Valdes-Reyna 2005).   Despite the large number of Eragrostis species, they are mostly unknown weedy grasses and only a few became known as forage grasses. The adverse effects of the frequent droughts that hit Africa, Australia and North America in the period between 1880-1930 led to a decrease in livestock production on grassland. The need for new grass species that could produce good quality forage under limited precipitation and heavy grazing was realized. This motivated a world-wide search for the “miracle grass” (see Cox et al. 1988 for more details). The search was lead by botanists, ranchers and even military personnel from Australia, England, South Africa, and the United States. After the evaluation of thousands of world-wide trials, the “winners” were four African grass species that were characterized by ease of establishment relative to native grasses, persistence, and high productivity as forage species.  These grasses were; weeping lovegrass [Eragrostis curvula (Schrad.) Nees], Lehmann lovegrass (Eragrostis lehmanniana Nees), buffelgrass (Cenchrus ciliaris L.), and kleingrass (Panicum coloratum L.). Eragrostis curvula and E. lehmanniana have been heavily utilized mainly in the USA and Argentina for soil conservation and forage production purposes. Another well known species is E. pilosa, a common weed in many parts of the world, and the most closely related to the cultivated species E. tef. Because this species is considered the progenitor of the cultivated tef, many studies were initiated on this weed and it is now part of the breeding programs for tef improvement in Ethiopia. The three species E. curvula, E. lehmanniana and E. pilosa will be the focus of this chapter.