Sara de Almeida Rios

Oil palm natural diversity and the potential for yield improvement

African oil palm has the highest productivity amongst cultivated oleaginous crops. Species can constitute a single crop capable to fulfill the growing global demand for vegetable oils, which is estimated to reach 240 million tons by 2050. Two types of vegetable oil are extracted from the palm fruit on commercial scale. The crude palm oil and kernel palm oil have different fatty acid profiles, which increases versatility of the crop in industrial applications. Plantations of the current varieties have economic life-span around 25–30 years and produce fruits around the year. Thus, predictable annual palm oil supply enables marketing plans and adjustments in line with the economic forecasts. Oil palm cultivation is one of the most profitable land uses in the humid tropics. Oil palm fruits are the richest plant source of pro-vitamin A and vitamin E. Hence, crop both alleviates poverty, and could provide a simple practical solution to eliminate global pro-vitamin A deficiency. Oil palm is a perennial, evergreen tree adapted to cultivation in biodiversity rich equatorial land areas. The growing demand for the palm oil threatens the future of the rain forests and has a large negative impact on biodiversity. Plant science faces three major challenges to make oil palm the key element of building the future sustainable world. The global average yield of 3.5 tons of oil per hectare (t) should be raised to the full yield potential estimated at 11–18t. The tree architecture must be changed to lower labor intensity and improve mechanization of the harvest. Oil composition should be tailored to the evolving needs of the food, oleochemical and fuel industries. The release of the oil palm reference genome sequence in 2013 was the key step toward this goal. The molecular bases of agronomically important traits can be and are beginning to be understood at the single base pair resolution, enabling gene-centered breeding and engineering of this remarkable crop.

Variabilidade de genótipos de milho quanto à composição de carotenoides nos grãos

O objetivo deste trabalho foi caracterizar e avaliar a variabilidade quanto ao teor e perfil de carotenoides nos graos de 134 genotipos de milho (Zea mays), com vistas a utilizacao em programas de biofortificacao. Os materiais foram provenientes dos campos experimentais e do Banco Ativo de Germoplasma da Embrapa Milho e Sorgo, Sete Lagoas, MG. Sao cultivares e hibridos comerciais, linhagens-elite e outros acessos escolhidos com base na coloracao amarelo-alaranjada do endosperma. A quantificacao do teor de carotenoides totais, carotenos e xantofilas mono-hidroxilada e di-hidroxilada dos graos foi realizada por metodo cromatografico-espectrofotometrico. As medias encontradas nos graos foram 22,34µ gg-1 de carotenoides totais, 2,55µ gg-1 de carotenos, 3,86µ gg-1 de xantofilas mono-hidroxiladas e 15,93µ gg-1 de xantofilas di-hidroxiladas. Os genotipos foram agrupados em 18 grupos pelo metodo de Tocher. O germoplasma da Embrapa possui potencial para ser usado em programas de desenvolvimento de linhagens de milho biofortificadas, quanto ao total de carotenoides pro-vitamina A.

Color of Corn Grains and Carotenoid Profile of Importance for Human Health

The increasing on the levels of carotenoids in staple foods of broad human consumption is one of the strategies of food biofortification programs, mainly due to the importance of these compounds to human health on the prevention of vitamin A deficiency. Maize is a major staple food due to its high consumption in regions where problems of Vitamin A deficiency are of great relevance. Maize biofortification programs have made progress in determining the amounts of carotenoids in grain of thousands of accesses. This work aimed at studying the influence of the color of the grains in the profile of carotenoids in four different Brazilian genotypes. The selection of ears within the same genotype was based on a color scale, considering the lighter (lightest yellow) in one group and the most colorful (darkest orange) in another group. Significant interactions (p 0.05) between the color of the grains and the genotypes for all the variables were detected in addition to genetic variability for both groups (lightest yellow and darkest orange). The colored ears of corn showed a high level of total carotenoids (TC) and fractions in RS 535 and RS 445, and the colorful ears of genotype RS 535 showed 300% more α + β carotenes (μg·g-1) in relation to lighter of this same material. The results of this study showed the influence of genotype on the grain color and content of carotenoids, indicating that breeders have the flexibility to make selection of some genotypes based on grain color, reducing cost and time compared to laboratory methods used for the screening of genetic materials.

Análise de trilha para carotenoides em milho

Path analysis for carotenoids in maize Although aspects of magnitude and significance are considered, the study of correlations between traits, alone, does not necessarily guarantee a cause and effect relationship between them. Therefore, the objective of this study was to use path analysis to allow the unfolding of correlations in direct and indirect effects, considering the carotenoids profile of maize genotypes. Data was obtained from the national assay of maize cultivars conducted by Embrapa Maize and Sorghum in the 2004/2005 growing season, with means of ten genotypes in five environments. The contents of total carotenoids (CT), alpha and -carotene, lutein, zeaxanthin and -criptoxantin were evaluated. Xanthophyll zeaxanthin provided the highest direct effect on -carotene. The high correlations between -carotene and total carotenoids and between -carotene and -criptoxanthin are due the indirect effect via zeaxanthin. The direct selection of genotypes with high levels of -carotene appears as a more effective alternative, but if other fractions of carotenoids were also considered, methods of simultaneous selection of characters using selection indices are more efficient in

Influence of the moisture at harvest and drying process of the grains on the level of carotenoids in maize (Zea mays)

Maize is considered a source of carotenoids; however, these compounds are highly unstable, degraded by high temperatures, exposure to light and presence of oxygen. The objective of this work was to evaluate the influence of the moisture and type of drying applied to grains on the level of carotenoids in yellow maize. The experiment was conducted in a completely randomized design (2 × 4 factorial), two levels of initial moisture at the harvest (22 and 19%) and three types of drying (in the sun; in the shade and in a dryer) and control (no drying). The samples of grains after drying with 12% of final moisture were analyzed by concentration of total carotenoids, carotenes (α-carotene + β-carotene), monohydroxilated carotenoids (β-cryptoxanthin), and xanthophylls (lutein + zeaxanthin). Initial moisture, type of drying and the interaction between moisture versus drying influence (p≤0.05) the levels of carotenoids in grains. This is the first report about the drying conditions and harvest’s initial moisture as influence on the profile and content of carotenoids in maize grains. Based on the results, this work suggested that the harvest be carried out preferably when the grains present 22% humidity, with drying in a dryer or in shade for further use or storage.