Variance components of corn hybrids evaluated in the usa corn belt
In the final steps of a corn (Zea mays L.) breeding program, thetest of the superior crosses is a standard practice involving yieldtrials in many test environments. The objectives of this researchwere to compare both the magnitude of the standard error ofprediction of three different linear mixed mo...
| Autores: | , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2006 |
| País: | México |
| Institución: | Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias |
| Repositorio: | Redalyc-INIFAP |
| OAI Identifier: | oai:redalyc.org:30240109 |
| Acceso en línea: | https://www.redalyc.org/articulo.oa?id=30240109 |
| Access Level: | acceso abierto |
| Palabra clave: | Agrociencias Zea mays L corn hybrid grain yield grain moisture variance components |
| Sumario: | In the final steps of a corn (Zea mays L.) breeding program, thetest of the superior crosses is a standard practice involving yieldtrials in many test environments. The objectives of this researchwere to compare both the magnitude of the standard error ofprediction of three different linear mixed models where locationand hybrid effects were considered random or fixed effects andthe magnitude of the phenotypic variance. Mixed, GLM, andVarcomp procedures from SAS were applied to grain yield andmoisture data obtained from 40 hybrids evaluated at 22 locationswithin the U.S. Corn Belt. Results showed that when using a linearmodel which considers both location and hybrid effects as randomeffects, rather than fixed effects, standard errors of prediction were33% smaller and differences could be detected with more accuracy.The three SAS procedures computed the same estimates of variancecomponents using balanced data, but with unbalanced data, onlyMixed and Varcomp procedures computed the same estimates.Phenotypic variance of grain yield was 52% smaller in Iowaenvironments, 9% smaller in Indiana environments, and 54%bigger in Illinois locations, compared to Nebraska environmentswhere the hybrids were made. |
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