disadvantages; alfalfa meal is high in fiber and low in energy; marigold petals are costly and lack nutrients so Carotenoids (provitamin A) and tocopherols (vitamin E) are lipid their use has decreased and replaced by synthetic yellow soluble antioxidants associated with decreased risk of several degenerative diseases. Both vitamins occur naturally in corn (Zea mays L.) pigments. These considerations emphasize a need for grain. Corn grain is a major component in diets of humans and ani-increased levels of carotenoids in corn grain. mals, and may have added value with increased levels of carotenoids The presence of antioxidants in lipids improves their and tocopherols. To estimate genetic variation among a group of stability and delays oil rancidity (Chow and Draper, inbreds and their breeding potential, we estimated combining abilities 1974; Weber, 1987a). Schaefer et al. (1995) and Williams of four carotenoids and two tocopherols in a diallel of 45 corn hybrids. (1997) found vitamin E supplementation in feed delayed Ten inbreds were chosen that varied in endosperm color (yellow to discoloration and prolonged shelf life of packaged beef, orange), tocopherol levels and oil content. Plants were grown for poultry, and food products. Animals fed corn containing two years (1998, 1999) at Urbana, IL, in an RCB design with three high levels of tocopherols could increase profits by rereplications. High pressure liquid chromatography was used to assay ducing waste caused by discolored products. The presfor four carotenoids (lutein, zeaxanthin, ␤-cryptoxanthin, and ␤-carotene) and two tocopherols (␣-tocopherol and ␥-tocopherol). Good ence of natural antioxidants, especially tocopherols, agreement between year means for the six compounds was observed gives corn oil flavor stability during storage and cooking. indicating minor environmental effects. Diallel analyses indicated, Increased levels of tocopherols should enhance shelf between 72 to 87% of the total sums of squares for hybrids for the life of corn oil (Weber, 1987b;Watson, 1988; White and six compounds was attributable to GCA effects. Significant SCA ef-Pollak, 1995). fects were found for several crosses. Estimates of GCA effects indi-Several studies have shown significant differences cated A619 had high values for lutein, ␤-cryptoxanthin, and total among corn inbreds for carotenoid and tocopherol levcarotenoids. Inbred R84 was a poor genotype for xanthophyll pigels. Blessin et al. (1963) reported ranges of 0.9 to 4.1 ments but a significant contributor for ␤-carotene and ␥-tocopherol, g g Ϫ1 for carotenes and 18.6 to 48.0 g g Ϫ1 for xanthoand total tocopherol. These genetic stocks indicate corn hybrids can phylls for 39 corn inbreds. Quackenbush et al. (1963) be developed with higher levels of provitamin A and vitamin E. evaluated 125 inbreds and found provitamin A amounts ranged from a trace to 7.3 g g Ϫ1 , lutein from 2 to 33 g g Ϫ1 . Forgey (1974) evaluated 20 inbreds and found

Vitamin E is the common name that describes eight naturally occurring compounds possessing alpha-tocopherol activity. These eight vitamin E compounds are collectively termed tocols, and all have antioxidant activity. There is natural variation among different corn breeding lines for levels of tocols. The two predominant isomers present in corn grain are gamma-tocopherol and alpha-tocopherol. Alpha-tocopherol is considered more desirable for human and animal consumption because it has higher biological activity than gamma-tocopherol. Most corn breeding lines naturally have much more gamma-tocopherol than alpha-tocopherol. Therefore a breeding goal is to increase levels of alpha-tocopherol relative to gamma-tocopherol. However, recent research suggests that gamma-tocopherol and compounds metabolized from it have properties important to human health that are unique from properties of alpha-tocopherol. Therefore it may be desirable to not only increase levels of alpha-tocopherol in corn grain, but also levels of gamma-tocopherol. Determination of levels of tocopherols in corn grain is very laborious, requires HPLC analysis and is too time consuming for use in routine commercial corn breeding programs. Therefore we are performing biotechnology enabled molecular marker mapping of chromosomal regions with genes that control levels and ratios of alpha- and gamma-tocopherol. Breeders can use molecular markers we have identified to expediently select for desirable alleles of genes that will improve levels of alpha- and gamma-tocopherol in corn grain, without having to perform laborious HPLC assays. Another biotechnology strategy we have initiated is genetic transformation of corn with the gamma-tocopherol methyl transferase gene to enhance conversion of gamma-tocopherol to alpha-tocopherol and thus increase levels of alpha-tocopherol. This transgenic strategy has been demonstrated in the model plant Arabidopsis, and we are now applying this approach to corn.

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ABSTRACT. Quality is considered to be mainly related to protein and oil concentration in maize kernel. Great effort has been made through the elevation of oil and protein concentrations; however, studies to enhance the composition quality of oil have been limited. Maize genotypes with special fatty acid composition may confer different end uses and added value. We investigated eight maize inbreds for kernel quality and fatty acid composition. Kernel samples from a two-year experiment were analyzed for oil, protein, moisture and ash, as well as several fatty acids, including oleic, linoleic, and linolenic acids. Results indicated differences among the genotypes for all traits, except for behenic acid. A680 appeared to be a promising parent to elevate oleic acid, while N194 and RSSSC were the genotypes with the highest oil and protein levels, respectively. A new statistical approach, Canonical Discriminant Analysis with Hypothesis-Error plot technique was utilized to evaluate the data. It showed a good level of agreement with linear tests, and show similar results with those of multi comparison test. With the easily understandable graphical outputs that can interpret the interaction of variables and cases, it offers a good alternative way in analyzing data.Keywords: Zea mays, oil, protein, multivariate analysis. RESUMO. Análise de linhagens de milho quanto às características de qualidade da semente e à composição de ácidos graxos por uma técnica multivariada. Considerase que a qualidade está relacionada principalmente com a concentração de proteínas e de óleos na semente de milho. Grandes esforços foram feitos para elevar as concentrações de óleos e de proteínas; no entanto, os estudos para realçar a qualidade da composição do óleo têm sido limitados. Os genótipos de milho com composição especial de ácidos graxo podem conferir diferentes utilizações finais e maior valor. Foram investigados oito linhagens de milho quanto à qualidade da semente e à composição de ácidos graxos. As amostras de sementes de um ensaio de dois anos foram analisadas quanto aos teores de óleos, proteínas, umidade e cinza, assim como diversos ácidos, incluindo oleico, linoleico e linolênico. Os resultados indicaram diferenças entre os genótipos para todas as linhagens, com exceção do ácido behênico. O A680 pareceu ser promissor para elevar os níveis de ácido oleico, enquanto o N194 e o RSSSC foram as linhagens com os níveis mais elevados de óleos e de proteínas. Uma nova abordagem estatística, a Análise Discriminante Canônica com a técnica de Hipótese-Erro, foi utilizada para avaliar os dados. Esta indicou bom nível de concordância com os testes lineares, e mostra resultados semelhantes aos do teste de comparação múltipla. Os resultados gráficos são fáceis de interpretar e constitui boa alternativa para análise dos dados. Palavras-chave:Zea mays, óleos, proteínas, análise multivariada.

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