For further information contact: John W. Miles

The genus Brachiaria includes the most widely used forage grasses in the American tropics. Traditional commercial cultivars are direct selections from ex situ germplasm collections of species of African origin. Except for the diploid sexual B. ruziziensis, existing Brachiaria cultivars (B. brizantha, B. decumbens, and B. humidicola) are polyploid apomicts. Genetic improvement projects were contemplated at least from the early 1970s to rectify the deficiencies of the existing commercial cultivars. However, apomictic reproduction (asexual reproduction through seeds) and ploidy differences among and within species blocked effective plant breeding until the mid-1980s, when a tetraploid sexual biotype of B. ruziziensis was developed in Belgium. In early 1988, this invaluable germplasm reached CIAT through our Brazilian colleague Dr. Cacilda do Valle, geneticist and plant breeder at EMBRAPA's National Center for Research on Beef Cattle in Campo Grande, Mato Grosso do Sul.

The cross-compatible, sexual tetraploid allowed recombination of genes that previously were reproductively inaccessible in tetraploid apomicts. The first experimental hybrids were tested in a small field trial in Colombia in 1989. From this modest beginning, a full-scale genetic improvement program developed over the succeeding years.

A Mexican-based forage seed company, Semillas Papalotla, multiplied and commercialized the first hybrid apomictic Brachiaria cultivar under the name Mulato. Its prime attributes are high yield and feed quality. However, Mulato's commercial success was limited by its low seed yield potential. A second hybrid, called Mulato II was released to the commercial market in 2005. Mulato II has better spittlebug resistance than Mulato and is more drought tolerant. The limited seed availability of Mulato II in 2005 has been overcome and seed is commercially available in most countries.

Continuing cycles of hybridization and selection seek to produce hybrids with enhanced expression of spittlebug resistance, forage yield and quality, seed yield, and other desirable attributes.

Related publications:

Miles, J.W.; do Valle, C.B.; Rao, I.M.; Euclides, V.P.B. 2004. Brachiaria grasses. In: Sollenberger, L.E.; Moser, L.; Burson, B. (eds.). Warm-season (C4) grasses. Agron. Monogr. 45. ASA, CSSA, SSSA, Madison, WI, USA. p. 745-783.

Miles, J.W.; Cardona, C.; Sotelo, G. 2006. Recurrent selection in a synthetic brachiariagrass population improves resistance to three spittlebug species. Crop Sci. 46:1088-1093.

Responsible: John W. Miles

Collaborators: Semillas Papalotla
(e-mail: mexico@grupopapalotla.com;
Web: www.grupopapalotla.com)