Diversidade genética e influência da aplicação de herbicidas pós-emergentes na composição de carotenoides em grãos de milho

• Ano de defesa: 2010
• Autor(a) principal: Rios, Sara de Almeida
• Orientador(a): Oliveira, Aluízio Borém de
• Banca de defesa: Gondim, Tânia Cristina de Oliveira , Cecon, Paulo Roberto
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Genética e Melhoramento
• Departamento: Genética animal; Genética molecular e de microrganismos; Genética quantitativa; Genética vegetal; Me
• País: BR
• Palavras-chave em Português: Biofortificação; Zea mays; Carotenóides; Interação genótipo x ambiente; Adaptabilidade; Estabilidade
• Palavras-chave em Inglês: Biofortification; Zea mays; Carotenoids; Genotype x environment interaction; Adaptability; Stability
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA::MELHORAMENTO VEGETAL
• Link de acesso: http://locus.ufv.br/handle/123456789/1308

The aims of this work were: 1. estimate the genetic diversity among maize cultivars in carotenoids corn grain composition; 2. estimate the genetic correlations and the relations of cause and effect through path analysis and 3. analyze carotenoids levels in maize submitted to different herbicides application. For the first two goals, it was used data from ten maize cultivars grown under different environments in the 2004/2005 growing season, using a randomized complete block design with two replications. As for the third objective, it was used BRS 1030 hybrid, in a completely randomized design with five treatments - without application; foramsulfuron iodosulfuron-methyl- sodium (40 g.ha-1), nicosulfuron (20 g.ha-1), mesotrione (120 g.ha- 1) and tembotrione (100 g.ha-1) and two replications. The chemical analyses were conducted at the Laboratory of Quality of Grain from the National Research Center of Embrapa Maize and Sorghum, located in Sete Lagoas, MG. Total carotenoids (TC), lutein, zeaxanthin, β-cryptoxanthin, α and β-carotenes, total carotenoids precursors of vitamin A (Pro VA), expressed on a dry basis and fresh weight (μg.g-1) and grain yield (kg.ha-1) were evaluated. The characteristics that most contribute to the genetic diversity among cultivars were lutein and zeaxanthin, considering the two evaluation environments. Positive and high correlation was found between β-carotene and the carotenoids zeaxanthin, β-cryptoxanthin and TC. However, only zeaxanthin showed high correlation and high direct effect on β-carotene. The post-emergent herbicides application evaluated did not reduce carotenoids contents, although the corn green composition presented differences for β-carotene and percentage of lutein and pro vitamin A carotenoids.