Beans and Other Paragons of Dietary Virtue

9 November, 2015 by (comments)

When the United Nations (UN) General Assembly designates an issue to be the focus of an international year, this is usually a tacit admission that people around the world tend to take the issue for granted, even though they shouldn’t.

The International Year of Pulses (IYP 2016) – which is being formally launched on 10 November at the headquarters of the Food and Agriculture Organization of the UN (FAO) in Rome – is no exception. Despite pulses’ nutritional and other virtues, and their enormous potential for helping confront the most daunting dietary and environmental challenges of our time, vital efforts to improve and promote these food grain legumes are often overlooked.

IYP2016Such has decidedly not been the case, however, at CIAT and several other CGIAR centers. Even though the big three cereals – rice, wheat, and maize – continue to have pride of place in CGIAR’s global crop research, center “mandates” also give precedence to the six most important pulses: common bean, chickpea, cowpea, faba bean, lentil, and pigeonpea. Moreover, in the last 4 years, our longstanding commitment to improve these crops has been reinforced by the CGIAR global research program on grain legumes.

For us, IYP 2016 thus offers a welcome opportunity to celebrate the major impacts that our research has registered so far, and also to call on donors and partners for renewed support. Their commitment is critical for translating the remarkable achievements of recent years into new rounds of improvement in global pulse performance, and in the food and nutritional security of the approximately 300 million people who depend on these crops.

So, be prepared, readers, for a steady stream of CIAT blog posts, publications, images, tweets, and other products over the next year – all singing the praises of the common bean (Phaseolus vulgaris). Every month, we’ll treat you to a unique bean type, bean scientist, bean-growing country, bean recipe, and bean fact.

Common bean is the most important of CGIAR’s six mandate pulses, in terms of global production and area planted, and donors’ investment in research on this crop has yielded especially high returns. According to a 2008 study, bean improvement had an estimated economic value of US$200 million – more than 12 times the cost.

Recent breakthroughs in the Center’s bean research respond to one of the crop’s greatest strengths –superior nutritional value – and also to one of its main weaknesses – poor performance under stress in comparison with other pulses.

Sometimes referred to as the “meat of the poor,” beans provide a low-cost source of protein, complex carbohydrates, and valuable micronutrients. Yet, even a nearly perfect food may still have room for improvement. To this end, CIAT researchers and their national partners used a breeding approach called crop “biofortification” – under the auspices of CGIAR’s HarvestPlus Program – to develop bean varieties possessing much-increased levels of iron. Offering a practical solution to widespread deficiencies of this key micronutrient among women and children, the biofortified beans have been adopted by more than a half million rural households in the Democratic Republic of the Congo and Rwanda.

In addition to its princely nutritional traits, the bean has a privileged evolutionary background, which has unfortunately given rise to a serious hereditary flaw. The crop was domesticated in a mid-altitude forested environment of tropical America, characterized by moderate temperatures and nutrient-rich organic soils. As a consequence, it isn’t really cut out for the warm, dry climate and poor soils of the areas in Latin America and eastern, central, and southern Africa where beans are widely grown today.

Nonetheless, through years of genetic improvement, CIAT scientists have succeeded in making beans far more resilient in the face of drought by changing the plant’s ancestral habit of delaying seed production when faced with water shortage. Two keys to success were the rich genetic diversity of beans safeguarded in the CIAT genebank, and skillful exploitation of certain root and shoot traits that contribute to drought tolerance.

Now, Center bean breeders are trying to marry increased drought tolerance to bean traits associated with higher yield under low soil fertility, another major constraint of production. The idea is to create a new generation of bean varieties that are highly robust under conditions that are typical of smallholder production.

A few years ago, our researchers discovered that many drought-resilient lines offer the added advantage of tolerance to temperatures 4 degrees Celsius above the crop’s normal “comfort zone.” Most of these heat-beater beans resulted from crosses made about a decade ago between common and tepary bean. The latter is a little-known “sister” species – another of the high-value assets tucked away in our genebank – that was domesticated in the arid climate of the southwestern USA and northern Mexico, and is more heat tolerant than any other grain legume.

In a further priceless coincidence of bean improvement, it turns out that some of the heat beaters have also been biofortified for high iron.

Even before these recent developments, modern bean varieties with improved yields and disease resistance were already widely adopted in Latin America and sub-Saharan Africa. In the latter region alone – thanks to the efforts of the national programs belonging to the Pan-Africa Bean Research Alliance (PABRA), which CIAT coordinates – the new varieties have reached more than 5 million rural households over the last decade or so. They have not only helped farmers strengthen food and nutrition security but also improve household income through the sale of surplus grain.

The groundwork is thus in place for a powerful bean-based response to two closely intertwined challenges that many developing countries now face. These are the impacts of climate change (including higher temperatures and more frequent drought) and a nutritional triple whammy that includes (1) continued prevalence of chronic hunger, (2) the larger but more subtle scourge of micronutrient malnutrition, and (3) rising incidence of overeating and diet-related diseases, such as diabetes and cancer.

To fully mobilize bean science against these challenges requires a major push to both consolidate the research that has made possible recent breakthroughs in bean improvement and also to accelerate the dissemination of new varieties through more concerted efforts to strengthen seed systems, as is being done in Ethiopia, Kenya, and Rwanda. We will highlight advances in those and other countries throughout IYP 2016.

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Filed Under: Beans @en, Crops @en