Vitamin-rich crop to help stave off life-threatening diseases in Africa

Plant researchers at the National University of Ireland Galway (NUIG) have helped to make a significant contribution to the fight against micronutrient malnutrition in Africa by collaborating on the development of new vitamin A-rich lines of maize.

In partnership with the International Institute of Tropical Agriculture (IITA), NUIG announced that it had recently succeeded in identifying lines of maize, one of Africa’s staple crops, that contain eight times the amount of vitamin A found in traditional maize seeds.

The results, which came about after two years of painstaking crop trials in Nigeria, means that poorer households in Africa should be able to obtain much more of the recommended daily allowance of vitamin A from their staple diet of maize.

By improving their nutrition using such “biofortified” lines of maize, they will be better able to stave off numerous life-threatening diseases that cause hundreds of thousands of deaths each year.

Micronutrient malnutrition – where people do not get enough nutrients such as vitamin A, iron, zinc and iodine to meet their dietary requirements – is a serious problem in the developing world, as it causes retarded growth, increases the risk of disease and can lead to reproductive disorders.

According to experts, vitamin A deficiency alone leaves 500,000 children blind each year in developing countries, and more than half of these children die within a year of losing their sight. In Zambia, 54 per cent of children under five are deficient in vitamin A, while in Nigeria the figure is 30 per cent.

The NUIG/IITA collaboration contributes to a global overarching programme called HarvestPlus, which involves dozens of research organisations that are trying to increase the micronutrient content of staple crops of the poor such as cassava, beans and maize.

The NUIG/IITA crop research was funded by Irish Aid which has a focus on improving smallholder agriculture and preventing maternal and child undernutrition.

Prof Charles Spillane, head of NUIG's Plant and AgriBioscience Research Centre, says that a diverse diet rich in micro- nutrients was out of reach of many of the world's poor because meat, fruit and vegetables are too expensive for them to buy.

Poorer households rely primarily on a few starchy staples that are rich in energy, but not micronutrients. However, enhancing the micronutrients content of these energy-rich staples can increase a person’s intake of these life-saving nutrients.

“The absence of micronutrients in people’s diet debilitates their physical and mental growth, so the human capital in countries where this is a problem is drastically impaired, and the burden of disease on the nation is dramatically higher,” he says.

Maize is the staple food for more than one-billion people in Sub-Saharan Africa and Latin America, and efforts have been ongoing for some time to develop lines that contain higher levels of vitamin A.

HarvestPlus has aimed to develop maize varieties that can deliver 50 per cent of a person’s daily vitamin A requirement. Until now, the currently released vitamin A-enhanced maize varieties meet only 20 per cent of the daily requirement.

It typically takes up to 10 years of breeding and testing with farmers and consumers to develop a new strain of maize that can grow well across an entire region.

The NUIG/IITA work on identifying which lines had the highest levels of vitamin A began in 2009, when maize breeder Girum Azmach was seconded from the Ethiopian National Maize Breeding Programme to do a PhD at NUIG. After testing 130 diverse lines of maize at multiple test sites in Nigeria, he was able to identify three lines that had the required target levels of vitamin A.

“The best one Girum identified had 17 microgrammes of vitamin A compared to the two microgrammes of the nutrient found in normal maize seeds,” says Spillane.

The high vitamin A lines of maize were developed by IITA’s breeding programme by breeding temperate strains containing high levels of provitamin A with tropical adapted inbred lines.

“In 2009, Girum began working on inbred lines which were at an advanced stage of breeding and hence closer to being ready to be incorporated into finished maize varieties by national programmes for African smallholder farmers.

“His four-year PhD research project was slotted into the 10-year maize variety development cycle. The IITA inbred lines used by Girum were previously developed by Dr Abebe Menkir’s IITA breeding programme to the ‘near to variety stage’ with funding from the HarvestPlus challenge programme,” explains Spillane.

The next phase of the project will see the seeds of the vitamin A rich maize lines being provided to national agricultural programmes for testing, local variety development, multiplication and deployment.

These high vitamin A lines will be provided to national breeding programmes in countries such as Uganda, Ethiopia, Sierra Leone and Liberia for use to develop their own vitamin A-rich varieties for smallholder farmers and the rural poor.

“What Girum achieved is important crop research work that needs to be done, as it is a significant step in the development of high vitamin A maize varieties that can be used across Africa to reduce micronutrient malnutrition,” says Spillane.

“From here the lines identified will be developed into finished varieties and provided to smallholder farmers at the national level.”

The NUIG/IITA research was recently published in the international scientific journal, BMC Plant Biology.