Successes in quinoa breeding programme

Increasing demand for quinoa makes agricultural companies in Germany interested in cultivating it too. Suitable varieties are being bred and researched at Kiel University. A new cultivation trial begins in April.

Close up of quinoa plant
© Monika Bruisch, Kiel University

These quinoa plants are one of six promising populations now being sown in small plots at the Hohenschulen experimental farm.

Quinoa is very popular, primarily in vegetarian, vegan and gluten-free cuisine. The seeds can be prepared like rice or cereal, but contain considerably more, higher quality protein. They are also a good source of iron, calcium and other valuable micro-nutrients. These benefits are also reflected in the growing demand for the product. Around 175,000 tonnes of quinoa were produced across the globe in 2020, more than double the amount produced in 2010. In 2020, Germany imported almost 8,000 tonnes of the popular "superfood", which is mainly grown in Bolivia and Peru. Import volumes have risen continuously over the past few years. Agricultural companies in Germany could also jump on this trend, but suitable varieties would need to be bred for this to work.

"Quinoa is a short-day plant. It only needs a few hours of sunlight to flower. And if it does not flower, it also means we cannot harvest any seeds," explained Dr Nazgol Emrani from the Institute of Crop Science and Plant Breeding (led by Professor Christian Jung). Emrani has dedicated five years to a research project on the genome analysis of quinoa and the breeding of new varieties for cultivation in temperate regions. The project has produced its first results. "First of all, we studied quinoa from 310 different provenances cultivated in the fields here. Of these, 90 were ripe at harvest time and so theoretically suitable for cultivation here." The genome was sequenced from all 310 provenances, also called accessions or genotypes. By comparing the genome and certain features of the plant (phenotype), it was possible to identify the genetic region, which is responsible for the time of flowering. Emrani: "This enables us to select the plants that also flower with long days. It means we no longer have to plant out 300 genotypes in the fields, we can just look at the genome."

As the next step, the scientist has cross-bred plants with favourable characteristics. That sounds simple, but was a particular challenge, said Emrani. This is because quinoa is a self-pollinator, which means that the flowers of a plant can be pollinated by their own pollen. In order to perform targeted pollination with a different variety, the anthers, i.e. the male part of the flower, must be removed from every single mother plant. Particular dexterity is required for this. "As quinoa has very small flowers, we had to use magnifying glasses to pull out the anthers. I thought it would never work. But we tried it and it was a success." How they did it and which method was successful in the end was published in an article by Emrani in the specialist journal Plant Breeding in 2020.

The offspring of these cross-breeds was propagated and plants with the desired characteristics were selected. There are currently six promising populations which will be planted out on small plots at the Experimental Farm Hohenschulen from April onwards. "There we will examine important features. Until then we will not know whether we have made a success of the cross-breeding," said Emrani, who is already very excited about how it will turn out. Alongside timely flowering and harvest, other factors play a role, such as plant height and side shoots. Some quinoa varieties can grow to three metres high. This is not beneficial because the plants can easily fall over. The best height would be between 100 and 120 centimetres. Pronounced branching of the plant is also undesirable as the seeds on the side shoots ripen at a later stage. A low saponin content is another goal of breeding. Saponins are bitter substances found on the seed coat. Emrani: "We have found lineages in our varieties that contain fewer saponins. We have also used these as parents for cross-breeding, in other words, they are included in our populations." However, it will not be possible to determine how high the saponin content is in the seeds until after harvesting. The plants can also be harvested using the same machines as used for rapeseed or corn, just with the settings adjusted for quinoa.

Author: Kerstin Nees