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Breeding maize exotic germplasm

By: Beltrán, J | Centro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT), Mexico DF (Mexico) | Arnel R. Hallauer International Symposium on Plant Breeding Mexico, D.F. (Mexico) 17-22 Aug 2003.
Contributor(s): Isakeit, T [coaut.] | Mayfield, K [coaut.] | Menz, M [coaut.].
Material type: materialTypeLabelBookAnalytics: Show analyticsPublisher: Mexico, DF (Mexico) CIMMYT : 2003Description: p. 7.Subject(s): Cropping systems | Fertilizers | Germplasm | Maize | Pesticides | Production factors | CIMMYT | Genetics AGROVOC | Plant breeding AGROVOCSummary: Maize breeders in the U.S. exploit a small fraction (less than 5% ) of the genetic diversity available worldwide. Therefore, it seems adequate to further develop breeding efforts to incorporate and combine exotic sources into the existing germplasm base to reduce the impact of unaccounted threats to production, and to enhance and facilitate current or alternate uses of maize. Exotic germplasm constitutes a reservoir of alleles and allele combinations that, once identified, can be incorporated and combined with elite local material. Several projects have focused on the characterization and utilization of maize germplasm: the Latin American Maize Regeneration Project (LAMRP), the Latin American Maize Project (LAMP), and the U.S. Germplasm Enhancement of Maize (GEM) Project. Land-Grant U.S. Universities and USDA projects have played an important role developing adapted lines and populations with exotic origin. For example BS16, BS27, BS28, and BS29 are temperate adapted populations, insensitive to photoperiod, derived from tropical populations ETO, Antigua, Tuxpeno, and Suwan-1, respectively, at Iowa State University (Hal1auer 1994). Temperate adapted inbred lines (NC296, NC296A, NC298, and NC300) with 100% exotic origin have been developed at North Carolina State University from tropical hybrids (Goodman et al. 2000). At Texas A&M University we focus on the use of white and yellow inbred lines developed by breeding programs in tropical and subtropical areas. Introduced exotic lines are characterized for adaptation, heterotic response, nutritional value, tolerance to abiotic stresses, and response to aflatoxin accumulation. Selected introductions are crossed with temperate lines to produce hybrids and breeding populations with different degrees of exotic material that are tested across subtropical to temperate environments under different water regimes (rainfed, full and limited irrigation). Overall, temperate inbreds from northern areas provide high yield, stalk quality, known heterotic response, and early vigor while tropical and subtropical germplasm from southern areas provides resistance and/ or tolerance to biotic and abiotic stresses (e.g., less aflatoxin, drought and heat tolerance) and kernel quality (more flinty endosperm texture) (Betran et a1. 2003). An additional effort is dedicated to characterizing and exploiting the genetic diversity of lines at the genotypic level and at specific genomic regions associated with target traits (e.g., drought tolerance) using molecular markers.Collection: CIMMYT Staff Publications Collection
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Conference proceedings CIMMYT Knowledge Center: John Woolston Library

Lic. Jose Juan Caballero Flores

 

CIMMYT Staff Publications Collection CIS-3825 (Browse shelf) 1 Available 632511
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Abstract only

Maize breeders in the U.S. exploit a small fraction (less than 5% ) of the genetic diversity available worldwide. Therefore, it seems adequate to further develop breeding efforts to incorporate and combine exotic sources into the existing germplasm base to reduce the impact of unaccounted threats to production, and to enhance and facilitate current or alternate uses of maize. Exotic germplasm constitutes a reservoir of alleles and allele combinations that, once identified, can be incorporated and combined with elite local material. Several projects have focused on the characterization and utilization of maize germplasm: the Latin American Maize Regeneration Project (LAMRP), the Latin American Maize Project (LAMP), and the U.S. Germplasm Enhancement of Maize (GEM) Project. Land-Grant U.S. Universities and USDA projects have played an important role developing adapted lines and populations with exotic origin. For example BS16, BS27, BS28, and BS29 are temperate adapted populations, insensitive to photoperiod, derived from tropical populations ETO, Antigua, Tuxpeno, and Suwan-1, respectively, at Iowa State University (Hal1auer 1994). Temperate adapted inbred lines (NC296, NC296A, NC298, and NC300) with 100% exotic origin have been developed at North Carolina State University from tropical hybrids (Goodman et al. 2000). At Texas A&M University we focus on the use of white and yellow inbred lines developed by breeding programs in tropical and subtropical areas. Introduced exotic lines are characterized for adaptation, heterotic response, nutritional value, tolerance to abiotic stresses, and response to aflatoxin accumulation. Selected introductions are crossed with temperate lines to produce hybrids and breeding populations with different degrees of exotic material that are tested across subtropical to temperate environments under different water regimes (rainfed, full and limited irrigation). Overall, temperate inbreds from northern areas provide high yield, stalk quality, known heterotic response, and early vigor while tropical and subtropical germplasm from southern areas provides resistance and/ or tolerance to biotic and abiotic stresses (e.g., less aflatoxin, drought and heat tolerance) and kernel quality (more flinty endosperm texture) (Betran et a1. 2003). An additional effort is dedicated to characterizing and exploiting the genetic diversity of lines at the genotypic level and at specific genomic regions associated with target traits (e.g., drought tolerance) using molecular markers.

English

0309|AGRIS 0301|AL-Maize Program

Juan Carlos Mendieta

CIMMYT Staff Publications Collection

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