Development and per se performance of CIMMYT maize populations as drought-tolerant sources
By: Edmeades, G.O | Centro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT), Mexico DF (Mexico).
Contributor(s): Beck, D.L [coaut.] | Bolaños, J.A [coaut.] | Edmeades, G.O.|Banziger, M.|Mickelson, H.R.|Peña-Valdivia, C.B [eds.] | Ortega C., A [coaut.] | Banziger, M [coaut.]
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Material type: 
BookAnalytics: Show analyticsPublisher: Mexico, DF (Mexico) CIMMYT : 1997ISBN: 968-6923-93-4.Subject(s): Drought resistance | Drought stress AGROVOC | Recurrent selection | CIMMYT | Genetic resources | Zea mays AGROVOC | Plant breeding AGROVOCDDC classification: 633.153 Summary: CIMMYT has been developing source populations for drought tolerance (DT) using two approaches. One involves recurrent selection of elite populations that has resulted in the production of lowland tropical sources of drought tolerance (Late-maturing: Tuxpeño Sequia C8; TS6 C3; La Posta Sequia C5; Pool 26 Sequia C3. Early-maturing: Pool 18 Sequia C4; Pool 16 C20). A second, slower approach has been to screen a wide range of improved and unimproved germplasm for unique sources of drought tolerance, and to combine these into a single gene pool which is then improved for agronomic performance. In 1986 22 sources were screened under drought for tolerance. The best 13 0f these were crossed in a diallel, and the individual crosses evaluated under drought. The best 74 (out of 168 possible) crosses were recombined in a half-sib crossing block for four cycles (i.e., to C4),and named Drought Tolerant Population-1 (DTP1). In C5 and C6 the breeding scheme shifted to recurrent S1 selection, and the best 222 prescreened S1 families were sib-increased and evaluated in multi-location international trials. In each cycle the best 40 S1 families were recombined. At the same time, 160 landraces and 156 elite source materials were evaluated per se and in crosses with DTP1 under drought In 1990 the best 25 of these were introgressed into an elite fraction of DTP1 to form DTP2, using half-sib crossing blocks for three cycles to ensure recombination. Both DTP1 and DTP2 were of mixed color, intermediate in maturity, with adaptation approximately 60-65% lowland tropical, 15-20% subtropical and 20% temperate. Presently the best fractions of DTP1 and DTP2 are being merged by grain color, improved for disease reaction, husk cover and drought tolerance, and inbred lines are being extracted. In international trials both populations perform at 90-95% of the level of La Posta Sequia C3, are superior under severe stress or in subtropical locations, and have shown a good level of stability across environments.Collection: CIMMYT Publications Collection
| Item type | Current location | Collection | Call number | Copy number | Status | Date due | Barcode | Item holds |
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| Conference proceedings |
CIMMYT Knowledge Center: John Woolston Library
Lic. Jose Juan Caballero Flores
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CIMMYT Publications Collection | 633.153 EDM (Browse shelf) | 1 | Available | 1X624179 |
CIMMYT has been developing source populations for drought tolerance (DT) using two approaches. One involves recurrent selection of elite populations that has resulted in the production of lowland tropical sources of drought tolerance (Late-maturing: Tuxpeño Sequia C8; TS6 C3; La Posta Sequia C5; Pool 26 Sequia C3. Early-maturing: Pool 18 Sequia C4; Pool 16 C20). A second, slower approach has been to screen a wide range of improved and unimproved germplasm for unique sources of drought tolerance, and to combine these into a single gene pool which is then improved for agronomic performance. In 1986 22 sources were screened under drought for tolerance. The best 13 0f these were crossed in a diallel, and the individual crosses evaluated under drought. The best 74 (out of 168 possible) crosses were recombined in a half-sib crossing block for four cycles (i.e., to C4),and named Drought Tolerant Population-1 (DTP1). In C5 and C6 the breeding scheme shifted to recurrent S1 selection, and the best 222 prescreened S1 families were sib-increased and evaluated in multi-location international trials. In each cycle the best 40 S1 families were recombined. At the same time, 160 landraces and 156 elite source materials were evaluated per se and in crosses with DTP1 under drought In 1990 the best 25 of these were introgressed into an elite fraction of DTP1 to form DTP2, using half-sib crossing blocks for three cycles to ensure recombination. Both DTP1 and DTP2 were of mixed color, intermediate in maturity, with adaptation approximately 60-65% lowland tropical, 15-20% subtropical and 20% temperate. Presently the best fractions of DTP1 and DTP2 are being merged by grain color, improved for disease reaction, husk cover and drought tolerance, and inbred lines are being extracted. In international trials both populations perform at 90-95% of the level of La Posta Sequia C3, are superior under severe stress or in subtropical locations, and have shown a good level of stability across environments.
Research and Partnership Program
English
9802|AGRIS 9702|anterior|R97-98PROCE|FINAL9798
Jose Juan Caballero
INT1888
CIMMYT Publications Collection
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