Wild relatives of crops – or – Crop wild relatives (CWR) are exceptionally useful plants. They contain an incredible amount of genetic diversity, representing an invaluable resource for crop improvement. Many of their traits have the potential to help crops become more resistant and resilient, enabling them to adapt to the new conditions caused by climate change.
Kew’s crop wild relative research aims to document, collect and share the wild relatives of crops in order to broaden the genepool available for pest and disease resilience and for agricultural improvement.
Astonishingly, some of the most widely cultivated crops on earth have relatives that are on the brink of extinction. Researchers have found that 12% of crop wild relatives are threatened by extinction and all are likely to have suffered a loss of genetic diversity due to urbanisation, climate change and conflict in hotspot areas.
Kew is part of a global crop wild relative project, storing seed at the Millennium Seed Bank, and in partnership with national and international gene banks and plant breeding institutes around the world.
The Madagascar Banana (Ensete perrieri, Musaceae) is a wild relative of the Abyssinian Banana (E. ventricosum). An extinction risk assessment of Ensete perrieri has been completed and published on the updated IUCN Red List this week. The IUCN Red List is the most widely recognised list that documents extinction risk of species. Two Kew scientists, Richard Allen and Hélène Ralimanana, have been working on assessing the Madagascar banana.
This species is found only in the dry tropical forests of western Madagascar and is under pressure from deforestation. Only five mature individuals of E. perrieri have been previously identified in the whole of Madagascar, and a recent survey has suggested that now only three of these may be left (Analavelona, Ampefy and Maintirano areas). Its Red List assessment classifies it as critically endangered (CR).
There are only a few localities known for this banana relative. Luckily seedlings have been seen growing around the bottom of mature plants, giving hope that these seedings will grow to become mature plants, capable of flowering and producing more seed. Plants have also been found growing in the Tsingy de Bemaraha Strict Nature Reserve. This is a protected area managed by the Madagascar National Parks, giving the wild banana protection from potential dangers to its habitat.
Kew Madagascar Conservation Centre has been part of a partnership, led by FOFIFA (National Center for Applied Research and Rural Development) conducting field surveys, looking for wild bananas. Forest clearance has been reported as a threat to wild banana populations. Burning is a traditional way to clear land for grazing animals such as zebus. But, increasingly, farmers are reported to clear areas by burning to get more space to cultivate food crops for their households (maize, cassava and sweet potatoes).
There are many endangered species in Madagascar including the Madagascar Banana. Now that we know how threatened this species is, we can look at making this a target species for collecting seed, and storing ex-situ at the Millennium Seed Bank, Wakehurst.
The current variety of banana most commonly sold in the US and Europe is called the Cavendish banana. However, it is coming under threat from several diseases.
Tropical Race 4 (TR4), a fungal disease, is one of the pathogens endangering the Cavendish. The fungus grows in the roots and xylem (veins) of the plant, blocking the passage of water and nutrients, causing the slow starvation of the banana. It is impossible to treat TR4 with fungicides and soil fumigants so the disease has already eliminated bananas in southeast Asia.
Cavendish Bananas are triploid, meaning that they have three sets of chromosomes instead of the two sets found in most plants. This chromosomal anomaly results in them being sterile which has three main effects: firstly, they have no seeds, which makes them more palatable, second, they can only be cultivated clonally via cuttings and third, because they are all genetically identical, there is no opportunity to find natural resistance to pests and diseases. So, while their wild relative, Ensete perrieri is not commercially viable as its fruit contains large unpalatable seeds, genetic diversity held within the seed may offer an opportunity to find some natural resistance genes that can be used for the development of new banana crops.
The extinction risk assessment of Ensete perrieri was undertaken as part of Kew’s contribution to the ‘Adapting Agriculture to Climate Change project’, supported by the Government of Norway and managed by the Global Crop Diversity Trust with the Millennium Seed Bank.
Meanwhile at Kew, we are redoubling our efforts to produce extinction risk assessments of thousands more plant species, co-ordinated through Kew’s Plant Assessment Unit. This work benefits from Toyota funding, which is being channelled to Kew through Toyota Motor Corporation's five year partnership with the International Union for the Conservation of Nature to develop the Red List of Threatened Species (TM).
- Richard, James & Hélène -
See the Red List assessment for Ensete perrieri
• Global Crop Diversity Trust (Crop Trust)
• Government of Norway
• Toyota Motor Corporation
• Kew Madagascar Conservation Centre (KMCC)
• National Center for Applied Research and Rural Development, Madagascar (FOFIFA)
A focal point for extinction risk assessments at Kew, funded by Toyota.
Within the vaults of the Millennium Seed Bank is the Seed Collection, which represents the greatest concentration of living seed-plant diversity on earth. The bank is a global resource for conservation and sustainable use of plants.
The tale of the sleeping beauties unveiled: Kew scientists delve deep into the seed vault of Kew’s Millennium Seed Bank to uncover the conservation value of the seeds stored at -20°C.