Dr. Bill Rooney, sorghum breeder, collaborated with the Centro Nacional de Tecnologfa Agropecuaria and Forestal (CENTA) in El Salvador in an effort to develop a brown midrib (bmr), dual purpose sorghum cultivar adapted to low input farming/livestock operations in Central America. The result was the development and release of the first bmr sorghum cultivar for the region that will aid subsistence farmers and others in the region.
The productivity of the Central American livestock and dairy industries are hindered by the lack of financing, a lack of infrastructure, and a lack of appropriate forage cultivars that provide sufficient quantity and quality forage or silage. Most of the livestock producers in the region are small land holders with limited resources; thus most of the Central American countries import dairy and meat products to meet increasing demand.
The environmental conditions in Central America make high quality forage production challenging. The tropical environment is home to a significant number of pests and pathogens that attack all crop enterprises and the seasonality of rainfall means extended periods of little rainfall that severely limits forage production. Forage production is plentiful to acceptable from mid-May through November, with rainfall frequency decreasing after August. Not only is the quantity of forage an issue during much of the year, forage quality in Central America is less than desirable for livestock and dairy production.
The forage sorghum industry has meaningfully improved forage quality in many areas of the world through the introduction of bmr sorghum. The bmr trait, which is known to reduce lignin concentration and thus improve forage quality, has been successfully introduced into many areas of the world, but has not been deployed in Central America. A breeding initiative to integrate the bmr trait into locally adapted grain sorghum, thus producing a dual purpose - forage + grain – commodity, was initiated by CENTA in El Salvador in 2005 by crossing a local cultivar, Tortillero, with B03292bmr from Bill Rooney’s program at Texas A&M AgriLife Research. The F1 was backcrossed to Tortillero and selections made in San Andres based on agronomic appearance and stability of the bmr trait. The B03292bmr parent was the source of the bmr trait and was develop by Dr. Rooney from the cross of BTxArg-11/BTx623bmr/BTxArg-1. The resulting B03292 was selected for the bmr trait and agronomic adaptation to College Station, TX and Guayanilla, PR.
Cultivar CI0941bmr was selected after testing in six countries: San Andres, El Salvador; La Lujosa, Honduras; Zacapa, Guatemala; Managua, Nicaragua; Guanacaste, Costa Rica; and Azuero, Panama. The selection was based on grain yield and biomass yield. Biomass, or forage, was evaluated for acid detergent fiber, neutral detergent fiber, acid detergent lignin, crude protein, total digestible nutrients, and in vitro dry matter digestibility, i.e., for forage quality.
Dr. Gary Peterson recently released 44 sorghum germplasm lines with resistance to grain weathering. These lines originated in the AgriLife Research – Lubbock breeding program of Dr. Darrell Rosenow (deceased). Breeding crosses were made at Lubbock and crossed seed grown in a Puerto Rico winter sorghum nursery. Selection and testing were conducted at Lubbock, Halfway, Corpus Christi, and Beeville for many years. Selections for resistance to grain weathering were made at Corpus Christi or Beeville in a humid, sub-tropical environment. These lines are resistant to grain weathering caused by diverse genera that include Fusarium spp., Curvularia spp., and Alternaria spp. They are of diverse pedigree and parentage and represent an array of grain color, plant color, and other agronomic traits.
The grain weathering resistance found in these lines was derived from several different and diverse genetic sources. Resistance of 33 lines is from published sources and 11 lines derive their resistance from internal breeding lines. These lines vary in their reaction to anthracnose with several exhibiting a high level of resistance. The lines are generally later in maturity, measured as days to flowering, than the commercial hybrids and plant height is similar to today’s hybrids. All lines are either purple or tan in plant color with red, white or lemon yellow grain color. All have normal, i.e., non-yellow, endosperm, are awnless, and do not have pigmented testa. Fertility restoration has not been evaluated but the parents of most of these lines are known R-lines in A1 cytoplasm, indicating that most are suitable as R lines. Dr. Peterson expects that these lines will provide the seed industry with sources of grain mold resistance in elite genetic backgrounds for use as seed or pollinator parents for the production of commercial hybrids. Additional information can be obtained for Dr. Gary Peterson at email@example.com.