Traits and technologies to boost North African protein self-sufficiency (BEANS4N.AFRICA)

Lead Research Organisation: University of Reading
Department Name: Sch of Agriculture Policy and Dev

Abstract

Faba bean is a grain legume whose nutritional value, particularly its high protein content, has earned it the nickname "poor man's meat" and for hundreds of millions of inhabitants of North Africa, the Nile Valley and the Middle East, it is the dominant source of staple dietary protein. Furthermore, in times when sustainable agricultural productivity is more important than ever, faba bean stands out as THE grain legume that combines very high yield potential, low environmental impact due its ability to fix its own nitrogen fertilizer in its root nodules, high nutritional value and widespread cultural acceptance.
Unfortunately, production of faba bean in North Africa has undergone a long-term decrease, simply because it is grown on far less land than just a few decades ago. The major reason for this alarming abandonment of areas previously planted to faba bean is not the result of a fall in demand but due to the spread of a parasitic weed known as broomrape (Orobanche). Broomrape is unable to photosynthesize and must attach itself to a host root system in order to develop and reproduce. The inability to eradicate it from infested soil arises from the fact that it produces up to two hundred thousand tiny seed per flowering head that can lie dormant for decades in the soil until triggered to germinate and attach when the chemical signature of a nearby host root is detected.
Fortunately, there are researchable solutions to equip the faba bean to live and thrive in the presence of Orobanche seed, but to succeed in the battle on the ground, there is a need to take action on several fronts. This project recognises faba bean as a key crop underpinning the most basic level of food security in North Africa and puts forward an integrated, multi-disciplinary programme of research that addresses the faba bean self-sufficiency issue at three different levels.
Firstly, we propose immediate investment in high throughput genetic profiling technology, which we will put to use in creating a map of the six chromosomes of the faba bean genome that is orders of magnitude more detailed than any currently available. This technological step change will mean many previously untackled problems such as finding genes that confer resistance or tolerance to a range of pests, diseases and stresses will become feasible. However, on its own, this technology would have limited relevance to the nutritional and economic welfare of the developing world.
Therefore, our second level of activity is to deploy this new mapping technology in partnership with some of North Africa's best breeders and geneticists to locate genes that confer two distinct mechanisms for thriving in the presence of broomrape: one mechanism involves removing the chemical signals that trigger parasite germination, the second mechanism involves improved ability to compete with the parasite after it has attached to the root. We will complement this gene hunt (which will improve future prospects for accelerated breeding of highly broomrape-tolerant faba bean protected by both mechanisms) with capacity-building work using two traits which can be efficiently selected for already - one a novel faba bean herbicide resistance that will permit treatment of the crop with herbicides that kill the broomrape and not the crop, and the second, removal of an anti-nutritional factor called vicine that causes a serious hemolytic disorder called favism in predisposed individuals constituting 5-10% of the population.
Thirdly, because no breeding achievements actually make a difference without widespread uptake of new varieties, we integrate here a thorough socio-economic study that will produce recommendations to the project participants on what and how to deliver their breeding and agronomy innovations to maximise uptake and more generally to governments and the foreign aid community to highlight bottlenecks and potential solutions in the rollout of new varieties and agronomy advice

Technical Summary

Uncontrolled spread of the parasitic weed, Orobanche crenata, across North Africa has led to a long-term decline in production of faba bean - a staple protein source - that impacts economic and nutritional welfare of smallholders and urban poor across the region.
We propose a multi-disciplinary research program focused on this key legume, together with partners in Egypt and Tunisia, to simultaneously address: 1. the need for an efficient, high-throughput genotyping platform to make rapid progress in quantitative genetics, 2. The opportunity to exploit new discoveries and genetic resources that promise to deliver major breakthroughs in our understanding of the genetics of host tolerance to Orobanche, 3. the desire of well-trained geneticists in our partner institutes in Egypt and Tunisia to partner directly with the UK to deploy existing traits and technologies and 4. the recognition that adoption of new traits and varieties can be improved through a better understanding of barriers to uptake.
Specifically, we will design and validate a 50K SNP genotyping array and use it do develop a high resolution genetic map based on a new multi-parent mapping population. High resolution genotyping and precision phenotyping of the Orobanche-faba interaction under controlled conditions will be combined to genetically dissect two distinct tolerance mechanisms - low strigolactone exudation and greater post-attachment competitive ability. Beside these mapping studies, we will also initiate a capacity-building breeding pipeline with our Egyptian and Tunisian partners to introgress two traits of immediate value - resistance to a sulfonylurea herbicide and low vicine-convicine (anti-nutritional) content - into locally adapted backgrounds. Finally, a socio-economic study of the agri-innovation systems in Tunisia and Egypt will ensure a better understanding by project participants of end user needs and involvement of stakeholders in designing ways to increase adoption rates and impact.

Planned Impact

The overarching impact this project has been designed to deliver is to secure stable, home-grown supplies of nutritious and affordable faba beans, traditionally widely grown and hugely valued across North Africa as a protein-rich and satisfying staple food, earning it the moniker of "poor man's meat".
The project works across disciplinary boundaries with inputs from life sciences, social sciences and economics to act across the whole agronomy and breeding innovation pipeline in two contrasting North African countries, Egypt and Tunisia to build the capacity of breeding to deliver better solutions to the challenges faced, faster.
The first area of impact surrounds the adoption of the ultimate products of the research proposed here: new varieties with combinations of Orobanche tolerance mechanisms and herbicide resistance. Such varieties have the potential for faba bean production to resume in heavily infested areas, achieving high yields and depleting the Orobanche seed bank year on year. To achieve this high level impact we envisage activities to ensure that marker-assisted breeding can be perpetuated in our current partner countries and others beyond the timescale of the project by facilitating planning for transfer of marker-based selection technologies to Tunisia and Egypt and by holding a workshop to involve non-project participants in sharing our experiences. We also envisage working on involving in-country stakeholders in gathering evidence to demonstrate the value of the traits being introgressed. Using the low vicine-convicine trait as an example, we plan to generate collaborations with an Egyptian University hospital which screens and treat favism sufferers to work with us on assessing the safety of our low vicine breeding lines.
The second area of impact is in breaking down barriers to uptake of varietal and agronomic innovations. Here the approach involves activities to partner with and widen the scope of extension projects already up and running, to extend the socio-economic study to a targeted engagement of key stakeholders and to use web and social media to disseminate and engage in interactive discussion with the wider public.
Thirdly, a desirable legacy of this project would be if our developing country partners feel empowered and capable of proposing quantitative genetics research into other traits of interest, in which UK collaboration might figure in a supportive role or not at all. Towards this end, our Tunisian and Egyptian partners will write research proposals by the end of this Foundation Award that embody their enhanced capacity to undertake internationally competitive underpinning research.

Publications


10 25 50