Quantitative variation for grain quality in Brazilian maize populations

Abstract

Development of maize (Zea mays L.) cultivars with high grain protein and oil concentrations and an appropriate amino acid composition, without losses in grain yield, represents a challenge in breeding programs. The objective of this work was to study the nutritional quality of ten Brazilian maize populations evaluated in three environments. A randomized block design with six replications was used. Ear yield and the concentrations of protein, oil, serine, glutamic acid, alanine, leucine, tyrosine and phenylalanine were evaluated. Individual and combined analyses of variance were performed. Populations diverged for most of the traits. Environmental effects influenced variation for most of the traits, unlike genotype-environment interaction, allowing the selection on the average of environments. Positive association exists among protein and most of the amino acids, when considered on a dry matter basis and there is no association between nutritional quality and yield; therefore, the development of cultivars that are superior for both traits is expected to be feasible. Key words: plant breeding, nutritional quality, protein, amino acids Variação quantitativa para qualidade de grãos em populações brasileiras de milho RESUMO: O desenvolvimento de variedades de milho (Zea mays L.) com maiores teores de proteína e óleo nos grãos e um balanço adequado de aminoácidos, sem prejuízo do rendimento de grãos, representa um desafio para o melhoramento. Estudou-se a qualidade nutricional em dez populações brasileiras de milho. As populações foram avaliadas em três ambientes. Os experimentos foram realizados em delineamento de blocos casualizados com seis repetições. Foram avaliados o rendimento de espigas e as concentrações de proteína, óleo, serina, ácido glutâmico, alanina, leucina, tirosina e fenilalanina. Análises de variância por experimento e conjunta foram realizadas. Há variação entre populações para a maioria dos caracteres estudados. Há efeito de ambiente para a maioria dos caracteres, mas não da interação genótipo-ambiente, permitindo a seleção para a média dos ambientes. Existe uma associação positiva entre o teor de proteína e o da maioria dos aminoácidos quando considerados com base na matéria seca e não há associação entre a qualidade nutricional e o rendimento. Portanto, é possível o desenvolvimento de cultivares superiores para ambos os caracteres. Palavras-chave: melhoramento, qualidade nutricional, proteína, aminoácidos

Diversity of Maize Kernels from a Breeding Program for Protein Quality: I. Physical, Biochemical, Nutrient, and Color Traits

“…The commercial germplasm base of maize is not considered to be heterogeneous (Singh et al, 2011) nor does it represent unimproved or unselected germplasm. The latter is considered to be an important genetic resource needed to protect the gains in maize yield, drive increases in genetic yield potential (Ortiz et al, 2010), and improve the nutritional quality of the crop (Mittelmann et al, 2011). End-use quality (Ortiz-Monasterio et al, 2007) as well as early performance and growth of agricultural crops are Table 5.…”

“…However, kernel contents of protein, oil, and starch as well as nutrient concentrations and kernel physical characteristics are important quality attributes (Moore et al, 2008;Goggi et al, 2008). The simultaneous improvement of some of the biochemical traits in maize while maintaining high grain yield, although difficult, is considered feasible (Mittelmann et al, 2011). There is ample variation for and interrelationships among multiple traits in this germplasm that can be manipulated by breeding and selection to develop maize varieties with a desired set of trait combinations.…”

“…More heterogeneous and heterozygous maize varieties are needed to provide genetically broad-based populations as sources of quality traits (Taboada-Gaytan et al, 2010). Characterizing relevant germplasm pools, understanding the structure of their diversity, and elucidating interrelationships between and within physicalbiochemical-nutrient-color traits should lead to enhanced germplasm use for the improvement of nutritional quality of maize (Harrigan et al, 2010;Mittelmann et al, 2011).…”

Rationalizing the Use of Water of Salinity Hazards for Irrigating Maize Grown in a Saline Sodic Soil

“…Thus the grains obtained in the current study were of higher protein content than those of the maize grains imported from China and Turkey. Even between the main exporters of maize grains worldwide which are Argentina and Brazil (USDA, 2013), protein content in grown therein maize is higher, where the protein content ranged from 88.0 to 119.0 g kg -1 in Argentine maize race (Robutti et al ,2000) and from 105.1 to 115.8 g kg -1 in the Brazilian maize (Mittelmann et al, 2011). …”

Genetic Diversity of Maize Landraces as Sources of Favorable Traits

“…In this context, the landraces represent a good source of genetic variability and may help to identify the most suitable materials for the development of more nutritious foods. Many studies have documented genetic and phenotypic variability for grain composition traits in maize (Pollak & Scott, 2005;Reynolds et al, 2005;Berardo et al, 2009;Has et al, 2010, Mittelmann et al, 2011.…”