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GENETIC IMPROVEMENT

Vitamin Enriched Cassava

More nutritious tubers and beans are available to feed Brazilians

100-103_Mandioca_200Leo RamosAgricultural staples richer in vitamins and nutrients than those currently consumed, such as a cassava with 40 times more vitamin A than the typical one, for example, are now in the final phase of field testing at the Campinas Institute of Agronomy (IAC). In addition, varieties of eight food species – pumpkin, rice, sweet potatoes, beans, cowpeas (black-eyed peas), maize (corn), cassava and wheat – richer in iron and zinc and with greater resistance to disease and climate change are already on the market or in the final phase of development at the Brazilian Agricultural Research Corporation (Embrapa). This is a process known as food biofortification, carried out through classical breeding methods that seek to crossbreed different varieties, such as plants with disease resistance, a high yield and good nutritional characteristics with more vitamins and minerals. The work is slow and time consuming and may take 10 to 15 years.

The new IAC cassava, called IAC 6-01, was first developed in 2000 and is still not quite ready for farmers. “We give this new variety to some farmers just to grow as a test,” says agronomist Teresa Losada Valle, the IAC researcher responsible for its development. “If it does not test well in the field, then having other qualities, such as greater nutrient density, does it no good.” Valle recalls that, strictly speaking, the work of improving this plant of the Euphorbiaceae family, native to western Brazil, is a continuation of something that began before Pedro Álvares Cabral discovered Brazil. “Indigenous peoples domesticated cassava and left us a great cultural and biological legacy: a rustic plant, well adapted to all Brazilian ecosystems,” says Valle. “Moreover, it is able to tolerate the very stressful conditions caused by pests and non-living agents such as drought or frost, for example, and meets the needs of today’s agriculture in terms of sustainability and low cost.”

Today, with annual production of about 27 million tons, Brazil is the world’s third largest producer, accounting for around 10% of the global total. The state of São Paulo produces 1 million tons per year, of which about 120,000 tons are of sweet cassava, while the rest is industrial for the production of flour and tapioca starch. “Production of the latter is done by small family producers who cater to local and regional trade,” says Valle. “In addition, there is another extremely important source of production, not included in official statistics. It comes from modern subsistence agriculture, done in backyards and small gardens on the urban periphery. This segment cannot be measured and produces less than the small family producers, but it has great socioeconomic importance because it is the basis of food security and generates income for the poor.”

Léo RamosValle, at IAC: “hopscotch” is also the result of research in the backyards of the urban peripheryLéo Ramos

Almost all of this production is to grow IAC 576-70, which began to be developed by the IAC cassava team in the 1970s and has been available to farmers since 1985. This cassava already had higher levels of vitamin A than the common variety. It was what earned Valle the 2012 Péter Murányi Food Prize, which is awarded by the foundation of the same name, for the social and economic importance that the variety had acquired over time. Also known as “hopscotch” or “five-seven-six,” this variety was the result of crossing the IAC 14-18, with white roots, also selected in the IAC, with the SRT 797 – gold-of-the-valley, with yellow roots. It was collected from rural farmers, cultivated for its own consumption and retained in the germplasm bank of the institute, which combines genetic material from several plants. According to Valle, who began her work on improving this plant in 1982, it started by selecting individual plants from crossbreeding, which had high yields, uniform roots and were resistant to diseases, especially bacteriosis, a cause of major epidemics in the central-southern region of Brazil.

The selection of plants with more carotenoids was made visually by choosing those with yellow roots that are characteristic of this nutrient. In a second phase they selected those with good organoleptic (sensory) characteristics, such as cooking time, texture and quality of the cooked food. Finally, they performed a chemical evaluation to quantify the proportion of vitamin A and carotenoids, especially beta-carotene. This phase confirmed the close relationship between the proportion of total carotenoids and the yellow coloring, and that almost all of the substance present in the variety was beta-carotene. Valle says that there are dozens of carotenoids, which give a yellow color to food plants, but only some of them are precursors of vitamin A, in other words, after they are ingested, they become the nutrient, the most important of which is beta-carotene.

Léo RamosCooked cassava: from left to right, common cassava; with 220 IU of vitamin A and the one with 800 IU, a deeper yellow colorLéo Ramos

According to Valle, the common cassava with white roots has 20 International Units (IU) (international measuring system for quantifying vitamins) of vitamin A per 100 grams of fresh roots, while the 576-70 variety has about 220 IU. For purposes of comparison, the daily requirement for an adult is 2,000 IU. The IAC 6-01, which is being developed by crossing the SRT 1221 (whisk-broom-yellow) with the IAC 576-70, will have almost four times more vitamin A than the 576-70 now on the market, or more precisely 800 IU. Furthermore, the two (576-70 and 6-01) yield twice as much crop as the ordinary plants and are much more resistant to disease and climatic and environmental changes.

Global Network
In the case of Embrapa, the project is more extensive. The company is part of a global network, HarvestPlus, which brings together researchers from various countries to work on food biofortification. “By using classical breeding techniques to obtain crop varieties with more nutrients, scientists found that biofortification was a way to improve the diet of poor families and provide alternative work for small farmers in countries around the world,” says Marília Regini Nutti, the HarvestPlus leader for Brazil, Latin America and the Caribbean, and researcher at Embrapa Agroindústria de Alimentos, based in Rio de Janeiro. “The goal is to obtain more nutritious basic foods.”

HarvestPlus emerged in 2002 as an initiative of the Consultative Group on International Agricultural Research (CGIAR), with funding provided by the Bill and Melinda Gates Foundation and other donors. Today the project is coordinated by the International Center for Tropical Agriculture (CIAT) and the International Food Policy Research Institute (IFPRI), an institute founded in 1975 with the goal of finding sustainable solutions to meet the need for food in developing countries. HarvestPlus has more than 200 agricultural and nutritional scientists worldwide.

Embrapa Embrapa maize (corn) in the process of selection for more nutrients.Embrapa

In Brazil, the project began in 2003, coordinated by Embrapa and it is now part of the BioFort Network, which brings together more than 150 professionals of various disciplines in 11 states. “Through this network created by Embrapa, we interact with universities, national and international research centers, associations of producers, the government, municipalities and non-governmental organizations,” says Nutti. “BioFort aims to reduce malnutrition and ensure greater food security by increasing the levels of iron, zinc and vitamin A in the diet of the poorest populations.” There are now eight agricultural products that Embrapa biofortifies. The goal is to produce varieties of pumpkin and maize (corn) with high levels of carotenoids and other precursors of vitamin A; rice, cowpeas (black-eyed peas), wheat and beans with high concentrations of iron and zinc (the latter also with great drought resistance); and cassava and sweet potatoes richer in beta-carotene. “So far, we have developed and launched 10 crops: three cassava and one sweet potato with higher levels of beta-carotene, three of cowpeas (black-eyed peas) and three of ordinary beans richer in iron and zinc,” says Nutti. “It took us about five or six years to develop each one, all by conventional breeding, not genetic modification.”

Cultural Heritage
The work of the IAC and Embrapa is not limited to developing new plants however. The two institutions also distribute them to farmers and thus to the population at large. “The HarvestPlus projects and BioFort consider the entire process of feeding people from the moment the food is produced until it reaches the consumer’s table,” says Nutti. “With this in mind, it considers and analyzes the responsiveness producers in rural communities have to new varieties. Therefore, it is important that these varieties, in addition to increased nutritional value, have agronomic and commercial advantages. “With this objective, Embrapa is working in collaboration with several Latin American countries, for example, Panama and Colombia. It has also sent some crops for adaptation testing in Haiti and is working with countries in Africa and Asia through HarvestPlus.

Biofortified foods can act as an innovative tool to improve the quality of life of the poor, as was the case of IAC 576-70. “The first segment to be targeted was low-income residents on the urban periphery, who arrived from rural areas as a result of migration caused by the modernization of agriculture in the 1970s,” says Valle. “These people brought with them their culture, seeds and knowledge of plants. Of these species, the most important was the cassava.” According to Valle, a large gene pool came with this to the periphery of urban areas, accompanied by popular knowledge of plants accumulated for centuries, so had nothing been done, this knowledge would have quickly been lost with the passing of generations and the integration of migrant children into urban culture.

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