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Hybrid rice for Latin America

April 24, 2013

Rice is the staple food of poor people in Latin America, a region with a Biofortified Rice 7_lopopulation of 577 million people; with an average annual rice consumption of 27 kilogrammes per person. 5.2 million hectares are under rice cultivation, but Central America, the Caribbean and South America still imports up to 3.4 million tonnes to meet demand. Just over 1% of the area under rice cultivation (about 70,000 hectares) is under hybrid seeds.

A new public-private partnership promises to boost rice productivity across the region. Launched in 2012, the Hybrid Rice Consortium for Latin America (HIAAL - Consorcio Hibridos de Arroz para America Latina in Spanish) brings rice scientists, traders, millers, and farmer organizations in 13 countries to develop high-yielding rice hybrids specifically adapted to the region. If successful, this initiative - led by the International Center for Tropical Agriculture (CIAT) - could transform the region into a global leader in rice production.

More vigorous rice

Hybrid rice involves crossing two distinct inbred rice lines to obtain genetically superior offspring that are up to 20% more productive. Hybrid rice production is well-established in Asia – over half of China’s rice comes from hybrids – and to a lesser extent in Africa. It is given high importance give by the CGIAR Research Program on Rice, the Global Rice Science Partnership (GRiSP), whose research aims to help meet the ever-growing world demand for rice.

Rice is self-pollinating, containing both male and female parts that produce offspring genetically identical to the parent plant. While this ensures the passage of particular characteristics from one generation to the next, it limits the options for crop improvement. To produce superior, hybrid rice that combines the beneficial traits of distinct rice varieties and takes advantage of “heterosis” – the tendency of crossbred varieties to outperform the parent plants – scientists first have to develop rice varieties with male sterility so that cross-pollination can occur.

As well as higher yields, the hybrid rice varieties developed by the Consortium will combine multiple additional traits that target some of the most critical constraints in the region. These include resistance to diseases, such as rice blast and rice
hoja blanca virus, and the need for high grain quality – essential for rice traders and processors. The varieties will also be developed to be better suited to the practice of direct seeding – the machine planting of rice seed straight into the ground, rather than the manual transplanting of seedlings common in Asia and Africa. Direct-seeded rice needs to have deep roots to avoid lodging – the windblown toppling of plants – and strong stems to bear the weight of heavy panicles. HIAAL’s hybrid rice research could combine all of these traits into single “super varieties.”

However, the adoption of hybrid rice technology in Latin America faces several challnges, including: issues of grain quality specially in appearance and milling yield; low seed production and and high seed prices; and lack of a distinct advantage for hybrids in environments with high yield potential.

If successful, the HIAAL initiative could make significant contribution to the global development of hybrid rice, including: adaptation to direct seeding with good tolerance to lodging; good grain quality for the indica;  a diverse germplasm group with long panicles and stay green traits; innovative breeding methods pioneered by EMBRAPA and Aceituno; and a significant market size.

Building on the best

In the newly established Consortium, CIAT will make the initial test crosses based on rice varieties in its own collection, those of the International Rice Research Institute (IRRI) in the Philippines, and the top-performing commercial rice varieties and experimental “elite lines” developed by participating institutions in Latin America. After initial testing, CIAT will distribute the hybrids to Consortium partners for subsequent testing and further improvement.

A system of royalties has been established to reward participating institutions when their rice varieties are used as parents of the new hybrid plants. The payments help ensure that participating institutions provide the breeding program with their best varieties and partners receive a steady stream of funds for continued investment in the initiative. “It’s high-risk, expensive research, but the benefits are potentially huge,” said Edgar Torres, leader of CIAT’s Rice Program. “But by forming a public-private partnership of this kind, we have two main advantages: access to the best germplasm – a lot of which is well adapted to the region – plus a strong, extensive testing network to test the varieties in different regions and environmental conditions. This is extremely expensive for private companies to do.”

One potential issue is that the benefits of the hybrid varieties only last one generation, before yields begin to drop and variability in the traits begins to creep in. For this reason, farmers will need to buy hybrid seed each year, instead of keeping a portion of their harvested seed for planting. For Torres, this is actually one of the advantages of hybrid rice in the region: “It means that farmers will have high-quality, certified seed each season, which will help to ensure consistently high yields and limit the spread of diseases and problems such as red rice. It also means that a seed market can be established, enabling us to reach many more farmers. With the deeper roots associated with lodging tolerance, we expect the hybrids to be able to access nutrients deeper in the soil, so the cost of buying the seeds will be partially offset by reduced expenditure on fertilizer.”

The first varieties to result from the partnership are expected to be formally released in 2016, with the establishment of a robust seed system to supply farmers with seed on a large scale, in around 5 years.

This piece is adapted from an article by published on the CIAT Website on the 23rd April, 2013, being an extract from the CIAT Annual report 2012-2013; and from the presentation Hybrid Rice in Latin America: A country report made by Edgar A. Torres of CIAT at the 6th International Hybrid Rice Symposium in Hyderabad, India, 10th - 12th September 2012.

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