Seleção de genitores comerciais e controle genético de características agronômicas e nutricionais de plantas de milho para silagem

• Autor(a) principal: Chaves, Luciana Gonçalves
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/4694
• topic: Zea mays; Silagem; Dialelo; Melhoramento vegetal; Zea mays; Silage; Diallel; Plant breeding; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA::MELHORAMENTO VEGETAL

Aimed to with this work to avaluate of parents in the commercial germplasm and identify the genetic control in advanced generations of forage maize hybrids with high nutritional value. Plants of the F1 and F2 generations of ten commercial maize hybrids recommended for silage production were crossed in a Diallel without reciprocals and obtained 90 hybrid combinations. According to the generation, 45 hybrid combinations and four witnesses were evaluated in two experiments conducted simultaneously. The design was a 7 x 7 lattice with two replications and the plot consists of two lines of four meters. Plants in each plot were harvested when the stage got grain mass / hard and ensiled for later determination of their characteristics bromatological., The data were subjected to analysis of variance and Diallel analysis as model 1, method 4 of Griffing (1956). Was established for the combined analysis of variance, the interaction hybrid combinations x generations showed no significant differences (P <0.05) to obtain the characteristics of green and dry matter, in vitro digestibility of dry matter, which indicates that the performance of hybrid combinations was consistent across two generations for this characteristics. However, there was a significant difference between the generations in some hybrid combinations of characteristics of plants and ear height, dry matter, crude protein and neutral and acid detergent fiber. In Diallel analysis was evident lack of genetic variability for yield of green and dry matter in the F1 generation and greater importance of additive effects for these traits in the F2 generation and showed for bromatological characteristics there was predominance of non additive effects of variance in both generations. The genitor BRS3003 and his F2 had the highest estimates of GCA for the characteristics of productivity and silage quality. Highlights are the hybrid combinations P30F90 x BRS3003, CD307 x Pointer, BRS3003 x 2B619, BRS3003-F1 x AG1051-F1, P30F90-F1 x BRS3003-F1, Valent-F1 x DKB466-F1 and Pointer-F1 x BRS3003-F1, as presented to the average productivity of dry matter (PDM) from 11.21 to 15.18 t / ha, the crude protein content (CP) from 7.86 to 11.01% and the best quality fiber, with an average high in vivo digestibility of dry matter (IVDMD, 62.65 to 73.73%) and low averages for the characteristics in neutral detergent fiber (NDF, 45.0 to 54.08%) and acid detergent fiber (ADF, 19.42 to 24.91%). It is a hybrid combination P30F90 x BRS3003 showed that the best means and ability to show the characteristics of interest and the performance of both generations, and 13.72 t / ha of PDM, 7.86% of CD, 73.73% of IVDMD, 45% of NDF and 19.99% of AFD in F1and 11.21 t / ha of PDM, 7.7% of CP, 71.36% of IVDMD, 48.35% of NDF and 20.36% of ADF in F2. This work demonstrates the commercial potential of germplasm for selection of parents for forage maize obtained from populations of advanced generation hybrids and the importance of not additive effects for bromatological characteristics.