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University of Copenhagen
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Fighting disease in the 'Bolivian' plant quinoa

Science — PhD student Carla Colque-Little is doing her research on disease resistance in quinoa plants. The topic is important for the Bolivian economy, but also for the recovery of national identity after years of colonialization.

»As we recover our pride in quinoa, we recover our identity,« says Bolivian PhD student Carla Colque-Little.

As part of the Plant Protection group at the University of Copenhagen, she is doing research on the quinoa plant’s resistance to the fungi disease downy mildew – a disease found in the vast majority of the plants.

The loss of quinoa at the heart of Bolivian identity, which Carla Colque-Little refers to, dates back to colonial times, when European conquerors did not see quinoa as the kind of ‘super food’ that many do today.

»They tried to erase the culture and the food – so quinoa became food for the outcast,« Carla Colque-Little explains.

Quinoa originates from an area surrounding Lake Titicaca in Peru and Bolivia and evidence indicates it was domesticated between 3,000 and 5,000 BCE. Spanish conquerors replaced quinoa with other crops during colonial times, and now – more than 500 years later – the Bolivian government and the UN are working to revive pride in the quinoa crop. The UN’s food and agriculture organisation FAO named 2013 the Year of Quinoa and the same year the Bolivian government set up an international quinoa center in Bolivia. The Bolivian government also supports research on quinoa, like Carla Colque-Little’s research, through scholarships. Her focus is on the diseases infecting quinoa leaves and seed.

Downy mildew »reduces the area of photosynthesis of the whole plant. It weakens it, and more importantly it goes inside the seed and preserves itself for the next season,« Carla Colque-Little explains. The disease reduces the harvest – especially if the plant is not a resistant species: »It could be by 90 per cent in a suitable environment for the pathogen«.

Downy mildew thrives in humid environments like in the lowlands of Bolivia especially near lakes. The disease is found worldwide, however, also in dryer areas.

»It is almost everywhere because it travels with the seeds,« Carla Colque-Little says.

New discoveries: Do not judge a book by its cover

Carla Colque-Little tested 100 different quinoa seeds from Bolivia to examine their reactions to downy mildew. During her experiments, she discovered something surprising in the plants, which looked to be untouched by the downy mildew disease.

»We we’re thinking ‘how can this be?’« Carla Colque-Little says about the day she showed her results to her supervisor.

»When we see dry conditions we don’t see the symptoms of this disease, so we thought it wasn’t there and it just died and the other diseases more suitable to dry weather came in and that was our assumption. But the DNA results show that it is still there in big proportions – we think it manages to survive with the help of other diseases,« Carla Colque-Little says adding: »That is very new« .

Carla Colque- Little’s PROJECT

Supervising institution:
University of Copenhagen

Collaborating institution:
University of Hohenheim

Main supervisor: Associate Professor Christian Andreasen

Co-supervisor: Postdoc Daniel Buchvaldt Amby

Previous supervisor: Associate Professor Ole Søgaard Lund

Carla Colque-Little began her PhD in Denmark in 2016 and will finish in 2020.

The PhD is funded by the Bolivian Ministry of Education as part of the ‘Scholarships for scientific and technological sovereignity’

Home institution: The Bolivian Ministry of Education 

Downy mildew and other diseases cooperate in the plant in what Carla Colque-Little describes as ‘symbiosis’. Looking into this symbiosis, the research also revealed which other diseases attack quinoa. According to Carla Colque-Little, the other diseases have only been documented in some internal reports in Bolivia, which did not go into the same depth as the research she currently works on. Her supervisors at the University of Copenhagen and collaborators at Hohenheim University have helped her develop experiments to elaborate on how downy mildew and other diseases live in symbiosis in quinoa.

»Internationally we do not have a set of genotypes with known reactions, so if we can start building this, it will be useful for studying the pathogen,« Carla Colque-Little says.

»These places are almost a desert. It is so dry, it is only sand, and the soil is poor. You can’t see many plants growing there except quinoa«

Carla Colque-Little

When her research finishes in 2020, Carla Colque-Little plans to publish a paper in an international journal on the 100 genotypes’ reactions to downy mildew. This, she hopes, can contribute to putting Bolivia on the world map of quinoa research.

Climate change calls for new crops

Interest in quinoa is growing because climate change will create harsher conditions for crops like wheat.

»There is a lot of interest all around the world because of the resilience of the plant,« says Carla Colque-Little, and refers to her recent field visit to the Bolivian highlands:

»These places are almost a desert. It is so dry, it is only sand, and the soil is poor. You can’t see many plants growing there except quinoa« .

Quinoa is resilient. It is also nutritious. Quinoa has up to 17 per cent protein, contains all of the eight essential amino acids, is rich on minerals like iron, magnesium and zinc, and on vitamin B, according to the FAO website. To revive quinoa, Carla Colque-Little thinks it is important to link the international knowledge with the reality of South America. Her stay in Copenhagen has proved useful in this regard:

»Being here has enabled me to meet prominent researchers throughout the world,« Carla Colque-Little says.

Highlands, lowlands, quinoa lands?

The mountainous landscape and bare, unprotected, land resulting in poor soil makes it hard to grow quinoa in the highlands. The humid environment in the lowlands, on the other hand, is favorable to downy mildew. The problems with growing quinoa in large quantities and growing exports, have made the crop expensive to buy in Bolivia. In addition, many Bolivians still think of quinoa as food for ‘indio’. ‘Indio’ is short for indigenous, a derogatory term meaning being from the countryside.

»The Spanish conquerors prohibited it. If you ate quinoa it meant you belonged to the indigenous tribes and that led to being discriminated against,« Carla Colque-Little says.

However, things are heading in the right direction.

»Even as a child I felt my country had a lot of poor farmers (…) I thought I wanted to help somehow and I am still trying,«

Carla Colque-Little

»Now we have a native president. He came to power in 2005 and we are recovering a lot of our identity, so if you look brown that’s good now. Things are changing slightly,« says Carla Colque-Little.

As you ascend to the highlands of Bolivia, people have a different perspective on quinoa.

»They know, they feel, they can see it is very nutritious to them,« Carla Colque-Little says, adding: »everything else will dry out and there will still be one stem of quinoa left … They are very proud of that« .

The growth in export of the plant has pulled some of the highland quinoa farmers out of poverty, but not made the communities rich. According to Carla Colque-Little, some big companies have taken advantage of the unregulated quinoa trade to become rich. These issues are among the reasons why Carla Colque-Little chose to study agriculture in the first place.

»Even as a child I felt my country had a lot of poor farmers (…) I thought I wanted to help somehow and I am still trying,« she explains. One solution is to improve commercialization practices and, say, label the origin and quality of the products to assure that the farmers get a fair price for what they produce.

Carla Colque-Little hopes to continue her research on quinoa when returning to Bolivia. Her goal is to support the quinoa sector through her academic work, while at the same time replacing the diet of coca cola and pasta with quinoa – thereby working to regain Bolivian identity and pride.

This article was produced in collaboration with UCPH SCIENCE and DDRN.

Listen to the podcast below to hear a longer version of the interview with Carla Colque-Little (also known as Carla Xinema-Little). The music used in the podcast is “Electro Lab” by Scott Gratton, produced under NonCommercial 4.0 International.