The seedbank that preserves historical wonder crops

Behind Kenya Agricultural Research Institute’s spirited efforts to save endangered plant species sits a little known storage facility: the National Gene Bank of Kenya, a repository that houses over 49,000 seed samples, both local and international, for long term seed conservation and safe keeping, making it the largest in Sub Saharan Africa.  

The seed repository’s up-to-date facilities for seed processing and drying, viability testing, sealing, packaging and long-term storage - for up to 20 years - complements the role of other regional gene banks, which only store seeds for a short time.

As a co-ordination of effort and intent the gene bank now represents a national asset, with seeds and crops previously grown in the country but since forgotten or wiped out still found, alive and well, in the gene bank. For example a high yielding, drought and pest resistance local maize variety grown predominantly in Central Kenya two decades ago, which farmers abandoned after new varieties came to the market, is still preserved in the gene bank.

“This maize variety is one of the wonder crops. Its what the farmers need, but unfortunately they think it was wiped out of the market and all they just need to do is come and request for it from the gene bank,” said Dr. Desterio Ondiek of the National Gene Bank.

Since the gene bank became operational in 1988, a total of 49,000 seed samples representing 165 plant families and 1,725 species have been assembled through both in-country collection missions and donations from within and outside Kenya. Over 60 per cent of the samples conserved are from Kenya, while the rest have come from more than 137 countries, including the UK, Asia and other African countries, with forage and cereal seed samples forming the bulk.

This has already led to some remarkable recoveries. For example, in 1989 a scientist travelled from Somalia to Kenya with a duplicate set of 284 samples of high yielding sorghum and maize genetic material from Somalia’s Baidoa/Afgoigene bank and brought them to the Kenyan gene bank. Two years later, a bloody civil war broke out in Somalia which has been going on to date.

The entire gene bank was bombed and all local plant crop varieties preserved in the gene bank destroyed. A survey carried out in Somalia in 2000 found that the prolonged state of unrest in Somalia has not only severely damaged farm production, but also led to the loss of some local crop species altogether.

But scientists keen on rebuilding Somalia are now travelling to the Nairobi gene bank to acquire the sorghum variety and repatriate it to Somalia for planting.

The gene bank is also the only duplicate global repository of sesame, having close to 2,000 recorded specimens of both wild and cultivated sesame assembled from over 50 countries.

Sesame is one of the worlds most sought after plants, whose seeds are used whole in cooking for their rich nutty flavor or for making the popular sesame oil. The seeds are also added to breads, including bagels and the tops of hamburger buns. Indeed, according to Assyrian legend, when the gods met to create the world, they drank wine made from sesame seeds.

The gene bank has two cold storage rooms each the size of a conventional bathroom with a storage capacity of 60,000 seed samples. One storage room runs at - 20ºC, while the other is kept at + 5ºC. There is also a dehumidified walk-in, walk-out drying unit, which runs at 20ºC and 18-20 per cent relative humidity with the capacity to handle over 200 seed accessions and dry seeds to below 5 per cent moisture content. Drying is key in seed storage, since moisture is thought to affect seeds’ shelf life.

Once the seed samples are collected from the field they are registered and given a unique number, called an accession number, for ease of registration. Tests are performed to check the health of the seed before continuing with the accession process, which comprises the recording of an addition of the new seeds to the bank.

 If seeds are in good condition, data received with the samples, including when and where the sample was originally collected, names or numbers allotted after collecting, and any other relevant information is recorded for documentation. The seed samples are then cleaned to remove debris and examined for fungal and insect infestation. The cleaning process ends with the drying of seeds with high moisture content, like fruits or recently harvested seeds, to levels that will increase shelf life without adversely affecting seed viability.

The seed samples are then packaged to prevent absorption of water from the atmosphere and contamination by pests. This is done by using securely sealed aluminum bags, which are placed in the seed store. Their location is recorded in a documentation system to ensure easy access of the seed sample anytime it is needed.

Once someone is interested in a seed sample from the bank, they have to make a formal request.  If there are enough of the seed in the store, a sample is removed and packaged for distribution. If there aren’t, the seeds must first be propagated to make more before any seed is distributed.  

However, while a majority of plants produce seeds which can be dried to enable long term conservation in seed banks, there are some that produce seeds which cannot withstand either dehydration or freezing. Other plants do not produce seeds at all and are vegetatively propagated.
The gene bank therefore also has field gene banks for crops such as cassava, yams, sweet potatoes, mangoes, sugarcane and coconut.

The next move, according to Dr Desterio, is to ensure the seed samples are conserved in other gene banks now being established in other countries. “In these times, you never know, anything can happen, and it would be really catastrophic if we lost the very important seed samples that we have in this repository, and which hold the key to food security globally. That’s why partnerships with other gene banks are key,” he said.

Written by Bob Koigi for African Laughter

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