To confront climate change, farmers in Vietnam bet on wild rice-derived lines
(Reprinted from the original on the Mekong Delta Development Research Institute website)
Bonn, Germany and Can Tho City, Vietnam (January 2020) – Scientists are collaborating with farmers in Vietnam in a new project which is striving to develop improved varieties of rice which can withstand the challenges of climate change by tapping into the genetic diversity available in the hardy wild relatives of rice.
Vietnam produces enough rice to feed its 96.5 million inhabitants and is the third largest rice exporter in the world, after India and Thailand. But in the Mekong Delta, where 90 percent of the nation’s total rice exports are produced, erratic climatic conditions are making it harder for farmers to bring in a good harvest.
Salinity, floods, pests and even drought are significantly decreasing rice yields in the Mekong Delta. Some of these risks are forcing farmers to increase their investment in inputs such as pesticides, fertilizers and reinforcement of irrigation systems, which consequently and negatively impacts the environment and their already-low profit margins.
“That is not an option,” said Dr. Huynh Quang Tin, Senior Lecturer at Can Tho University. “What farmers in the Mekong Delta need are more resilient and high-yielding varieties that can thrive in their particular local environments, whilst facing this new unpredictable reality. And a little wild crossed back into our domesticated rice might give our farmers a proper more sustainable solution for rice production.”
The “little wild” that Dr. Tin refers to comes from a wild rice ancestor, Oryza rufipogon L., which was previously crossed with an elite Asian rice cultivar – Oryza sativa IRRI 154 – to develop new varieties that can adapt to and tolerate challenging environmental conditions. Today, under Dr. Tin’s leadership and guidance, 13 farmers’ groups – known as Seed Clubs – are evaluating and selecting the wild-derived lines in the Mekong Delta.
“The Seed Clubs are growing these wild rice-derived lines on their farms. They then select the most promising individuals to be regrown the coming season,” said Dr. Tin. “Farmers here harvest rice two or three times a year. This means that in a year, we are going through at least two selection cycles, choosing materials that really respond to the needs of each location.”
These Seed Clubs are located throughout the Mekong Delta, in eight of the region’s 12 provinces. The production challenges each of these farmer groups face are far from homogenous. For examples, in the An Giang province, on the north-western part of the delta, the Nui Voi Seed Club’s farmers are selecting the most promising lines based on drought and heat tolerance, number of panicles per plant, short-cycle duration, and resistance to blast disease, one of the most devastating cereal diseases that causes 10-30% of the global yield loss of rice.
In the Dong Thap province, in the central part of the delta, the Dinh An Seed Club is selecting the most promising lines based on tolerance to acid sulfate soils, high yield, and short-cycle duration. And in the Bac Lieu province, one of the coastal provinces of the Mekong Delta, the farmers of the Lang Tron Seed Club are selecting the most promising lines based on tolerance to salinity, strong stem, high yield, and short-cycle duration.
A Breeder-Farmer Collaboration
This participatory plant breeding (PPB) project started in late 2018. It is funded by the Global Crop Diversity Trust (Crop Trust) and is part its Crop Wild Relatives (CWR) Project, a global effort funded by the Norwegian Government that supports the collecting and use of CWR, the distant cousins of our domesticated crops, which house beneficial traits that can help “climate-proof” our food crops.
“Dr. Tin has a long, successful record of working with farmers in developing and releasing new rice varieties,” said Dr. Benjamin Kilian, Senior Scientist at the Crop Trust. “With his support, many of these farmers have become, in their own right, breeders themselves. Some of them have already released new rice varieties in the region.”
“The world needs more of these collaborations between breeders and farmers, as it is farmers who ultimately adopt, or not, new crop varieties,” he added.
The project, officially known as ‘Participatory Evaluation of Crop Wild Relative Introgressed Genetic Resources in Rice in the Mekong Delta, Vietnam’, builds on another Crop Trust funded pre-breeding project, wherein researchers from Cornell University and The International Rice Research Institute (IRRI) used four widely different accessions of the wild rice Oryza rufipogon L. (originating from Bangladesh, China, Malaysia, and Papua New Guinea) to develop the materials that are now being evaluated in Vietnam. That initial project was carried out between 2011–2016.
A Wild Promise
Half of Vietnam’s paddies are located in the Mekong Delta, where 80 percent of the 17 million people who live there are engaged in rice cultivation. Rice is their livelihood, their predominant dietary energy source, and a key ingredient in their national cuisine and culture. The Government of Vietnam has been continually implementing rice improvement programs. But the present environmental conditions and climate-related threats in the region are increasing, so Mekong Delta farmers are eager to promote the release of promising varieties that can respond to these realities.
Based on initial results, Mekong Delta farmers affirm that some wild rice-derived lines are well adapted to drought conditions in the An Giang province, and acid sulphate soils in the Vinh Long province. Most have also proven to be resistant to blast disease and the brown planthopper, which reduce rice production in all project sites.
Additionally, these new, wild-derived lines will also help to curb the pollution brought about by the intensification of agriculture, which is negatively affecting the soils, water, and farmers’ health in the region. Currently, half of the Mekong Delta rice farmers are using 30% more pesticides than needed, mostly to deal with insects, diseases or the golden snails. In monetary terms, this equals to USD 400 million wasted per year. Chemical fertilizers, which account for about 30% of a farmer’s total production cost, are also overused, which equates to USD 150 million wasted per year. Rational use of these inputs will minimize the impact on the land and on the farmers’ health and wallets.
“Overall, after the first two growing cycles, the farmers are very happy with the preliminary results,” said Dr. Tin. “I am too. And believe that by the end of the project in December 2020, the best of the wild rice-derived lines will be nearly ready to be released and shared with more farmers across the Mekong Delta.”
The Vietnamese word cơm translates literally to “cooked rice”; it is used as the general term for food. For most people in Vietnam, rice is their food security crop. And a “little wild” in these new materials will make a big difference in the lives of farmers in the Mekong Delta, and the countless rice eaters around the world who consume it too.
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The “Participatory Evaluation of CWR introgressed genetic resources in rice in the Mekong Delta, Vietnam” is one of 19 pre-breeding efforts (100+ partners in 45 countries) which form part of the Crop Wild Relatives Project “Adapting Agriculture to Climate Change: Collecting, Protecting and Preparing Crop Wild Relatives,” funded by the Norwegian Government, and coordinated by the Crop Trust. http://www.cwrdiversity.org/
All agronomic and genetic data generated throughout this project will be shared in the future on the online platform Germinate, a database platform that provides a standard and common interface to genetic resources collections.
Seeds of the improved wild-derived ricelines developed during this project will be stored at Can Tho University and IRRI (Philippines) and shared under the terms and conditions of the Standard Material Transfer Agreement (SMTA) within the framework of the multilateral system of the International Treaty for Plant Genetic Resources for Food and Agriculture.
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