Mass selection for agronomic performance and resistance to ear-feeding insects in three corn populations
Tropical and sub-tropical corn (Zea mays L.) germplasm from Central and South America and the Southern United States is a promising source for corn earworm ( Helicoverpa zea Boddie) and fall armyworm (Spodoptera frugiperda J .E. Smith) resistance. This germplasm, however, possesses undesirable allel...
| Autores: | , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2001 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/46176 |
| Acceso en línea: | http://hdl.handle.net/10261/46176 |
| Access Level: | acceso abierto |
| Palabra clave: | Zea mays Helicoverpa zea Spodoptera frugiperda Tropical germplasm |
| Sumario: | Tropical and sub-tropical corn (Zea mays L.) germplasm from Central and South America and the Southern United States is a promising source for corn earworm ( Helicoverpa zea Boddie) and fall armyworm (Spodoptera frugiperda J .E. Smith) resistance. This germplasm, however, possesses undesirable alleles for other important traits that cause poor agronomic performance. The objective of this research was to determine the effect of 10 cydes of mass selection for improving agronomic performance and maintaining insect resistance in three populations that include exotic and southern U.S. germplasm. Selected populations were tested for selection responses in a two-year experiment with two planting dates in each year at Tifton, Georgia. Linear regression coefficients were used as estimates of the average rates of selection response per cycle. Yield increased after two.cycles of mass selection, but yield was either maintained or reduced in subsequent cycles. Resistance to corn earworm and fall armyworm and lodging remained unchanged in the three populations studied. Days to pollen shed, plant height and ear height were all significantly greater after selection. A few cycles of mass selection seemed useful in purging these populations of deleterious alleles. Second cycles of each population might be the most useful sources of germplasm because they had the greatest improvement for yield when compared with the original populations. |
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