Genes of Gold
The top-level biennial meeting of the United Nations Convention on Biological Diversity (CBD) is now underway in Hyderabad, India – not far from our ICRISAT Headquarters. A crucial challenge for this Eleventh Conference of the Parties (COP-11) will be to mobilize the resources needed to achieve the twenty biodiversity conservation targets for this decade that COP 10 agreed upon two years ago.
Mobilizing resources for major global initiatives is always challenging. It is difficult to convince voters of the priority and urgency of issues such as biodiversity loss and climate change. These issues seem too big and too abstract, too far from the daily lives of citizens, to merit their attention and action.
Recognizing this problem, the CBD strives to better articulate the case. One of its top-level initiatives is ‘The Economics of Ecosystems and Biodiversity' (TEEB). TEEB “seeks to draw attention to the global economic benefits of biodiversity” and “to highlight the growing costs of biodiversity loss and ecosystem degradation”, among other objectives.
A major part of our work at ICRISAT has much to do with the first of these objectives – generating benefits for the poor from agricultural biodiversity (agro-biodiversity). We scour the world for genetically-diverse types of our five focus crops that we can use in plant breeding to improve crop productivity and crop tolerance/resistance to diseases, insects and environmental stresses.
Our experiences certainly support the case made by TEEB. To illustrate the value of agro-biodiversity, I’d like to briefly describe ten “genes of gold” traits that are having enormous impact in our five focus crops.
1. Resistance to the downy mildew fungus
Before resistance became available farmers often lost half of their yields of millet grain to this disease. Our scientists found resistance in land races (farmer-evolved varieties) from Africa and Asia, and incorporated it into high-yielding modern varieties on both continents. We estimated in 1996 that the annual benefits were worth US$50 million, and have surely grown since then.
2. Iniadi land races from West and Central Africa
Iniadis are a distinct genetic type of pearl millet that have contributed a number of important qualities to our breeding pools: high dry matter, early maturity, cytoplasmic male sterility and good combining ability (requirements for breeding hybrid varieties), tolerance to drought, high levels of nutritious iron and zinc in the grain, and resistance to downy mildew. Iniadi genetic heritage has contributed to most of the varieties developed by ICRISAT. The benefits of these many traits are difficult to isolate and quantify in dollars, but have been enormous.
3. Higher yields from intercrossing between Caudatum, Guinea, and Durra races
Cultivated sorghum encompasses five sub-types or ‘races’. Intercrossing among the above three, which originated in different regions of Africa and Asia, combined a number of strengths. A particular benefit was that some crosses resulted in ‘hybrid vigor’, that is, more vigorous growth and approximately 40% higher net income from the crop for millions of farmers in India. Efforts are underway to develop hybrid seed systems and varieties in Africa.
4. Resistance to grain mold
The densely-packed grains of high-yielding Caudatum varieties of sorghum can become moldy when rains are unusually frequent, causing 30-100% yield losses, lower market value and even nutritional hazards for humans that consume them. In 1992 ICRISAT estimated the annual economic losses in Asia and Africa as US$ 130 million. Moderately-resistant land races were found and grain mold tolerant hybrids have been released in India. In West and Central Africa, Guinea land races are inherently resistant, though lower-yielding.
5. Resistance to fungal leaf spot diseases
Groundnuts (peanuts) are particularly susceptible to attacks by fungi. Moderately resistant land races have been found and utilized in breeding in both Africa and Asia. For example, ICG 7878 was selected directly from germplasm collections as resistant to both early and late leafspots and was released by Mali in 2002 as ‘Waliyar Tiga’; similar successes have occurred in other regions.
6. Early maturity
Early maturation of the crop is a trait that is greatly appreciated by poor farmers worldwide. It enables them to harvest food and receive income sooner, and to escape many droughts. The groundnut line most utilized in breeding this trait, ‘Chico’, has contributed earliness to cultivars released across Africa and Asia such as ICGV 91114, now having major impact in Anantapur district, India – the largest groundnut growing district in the world; and Nyanda (ICGV 93437), cultivated on about 50,000 hectares in Zimbabwe, Zambia, Mozambique, and South Africa.
7. Early maturity
Early-maturing chickpeas are having major impact in Ethiopia, India and Myanmar. Benefits to Ethiopia alone over the period 2001-2030 are projected to be worth US$111 million. The land area sown to chickpea in Myanmar, and also the grain yields per unit land area both doubled during 2001-09. In Andhra Pradesh state, India the early-maturing varieties stimulated a fivefold increase in sown area plus a 2.4-fold increase in yield over the same period.
8. Fusarium fungal wilt resistance
Fusarium wilt strangles a plant by cutting off the flow of water to its shoot. We identified resistant chickpea land races such as WR 315 and deployed this resistance in varieties around the world. In combination with early maturity this enabled the chickpea revolution in Andhra Pradesh that I described above.
9. Fusarium wilt resistance
Fusarium wilt resistance has also generated enormous impact in pigeonpea. Its agro-biodiversity source is an Indian landrace ‘ICP 8863’ that was released in 1986 as ‘Maruthi’ for cultivation in Karnataka, Maharashtra and Andhra Pradesh states. The value of wilt resistance from ICP 8863 was estimated at US$ 61.7 million by 1996, and continues to deliver enormous benefits in both Asia and Africa to this day.
10. Hybrid seed system
ICRISAT and partners utilized Cajanus cajanifolus, a wild relative species of pigeonpea, to develop the world’s first hybrid seed system for any grain legume crop. In more than 2,000 on-farm trials conducted in five states of India these hybrids produced an average 30% higher grain yield than the best available local variety. We expect enormous impact over the rest of this decade as seed enterprises make these hybrids widely available to farmers.
Will gold turn to dust?
These ten examples are just the beginning. We and many others are actively mining for more genes of gold. The new tools of molecular biology and genetics are enabling us to mine faster and deeper than ever before.
The risk, though is that the gold could be gone before we find it – if humanity continues to permit the accelerating erosion of Earth’s biodiversity resources. Perhaps one way that we can give back in return for all that we’ve gained, is by better explaining those gains to the world – and by better explaining how much poorer we all will be if we continue our careless ways.