Madang Province in Papua New Guinea is home to an International Coconut Genebank, a collection of the South Pacific’s coconut palm species to conserve the diversity of the species across the region.
That collection is now under threat from Bogia coconut syndrome (BCS), a largely fatal bacterial disease first identified in nearby coconut groves in Madang Province in 2008.
An ACIAR-funded project launched in 2019 is working with partner countries in the Pacific region to collect, conserve and redeploy the collection to protect the future of the crop and the Pacific island communities that rely on coconuts for food, construction materials and income.
Coconuts contribute directly and indirectly to the livelihoods of approximately 5 million vulnerable people in the coastal communities of the Pacific islands.
BCS is caused by a phytoplasma, a group of bacteria that also causes the more common lethal yellowing disease that affects many palm species. BCS is primarily spread by insects, making it difficult to contain, and it is usually lethal to infected palms.
Papua New Guinea was initially chosen as the site of the gene bank in the 1990s because it had few coconut pests and diseases. But the appearance of BCS, along with other disease threats on the horizon, is driving the search for new ways to conserve the region’s coconut genetic diversity.
One tactic has been to move trees to other countries. But this comes with the risk of spreading BCS outside Papua New Guinea, where it is currently contained.
This has led to the ACIAR-supported project to develop new approaches to conserve coconut genetics while reducing the risks of disease transfer.
The Pacific Community (SPC) is leading the research, with support from the University of Queensland and agricultural government ministries in Fiji, Papua New Guinea, Samoa, Solomon Islands and Vanuatu.
There is a high level of coconut diversity in these countries, and we’re trying to characterise and preserve their diversity.
Dr Carmel Pilotti
Associate Scientist for Coconut Genetic Resources with the SPC Land Resources Division and Project Lead
Due to a long history of human interference, coconut varieties have huge variation in physical characteristics, including colour, size, shape and husk proportions. Through the characterisation of the genetic structures that drive these physical differences, breeding programs will have the ability to become more targeted.
‘Through partnerships with these countries and the University of Queensland, we’re working to develop tissue culture laboratory protocols to conserve Pacific coconuts,’ said Dr Pilotti.
This involves collecting isolated embryos from mature coconuts and using tissue culture to germinate plants in laboratories. The new coconut trees are then planted out in a new field collection at the Pacific’s regional gene bank, the Centre for Pacific Crops and Trees, housed at SPC in Fiji. The 5-year project also aims to improve coconut cryopreservation (ultra-low temperature freezing) processes. This allows samples of genetic material to be preserved cryogenically (in a suspended, frozen state) to create a gene bank that is less labour-intensive than field collections and also more protected from biosecurity threats such as BCS.
‘The idea is to have the germplasm available and fully characterised so the countries can look at the varieties and make a choice on what they want to be introduced to their breeding programs,’ explained Dr Pilotti.
Characterising the gene bank creates the potential for new markets by selecting and breeding varieties for specific uses and products, to develop value-added coconut enterprises.
Dr Pilotti said this will increase opportunities for smallholder farmers to replace aged trees with cultivars that show increased coconut production, improved quality and greater adaptability to challenges such as climate change and biotic threats.
The tissue culture program relies on the movement of coconut germplasm between countries. Dr Visoni Timote, plant pathologist adviser at the SPC Land Resources Division, highlighted the development of protocols for the safe exchange of genetic material as a crucial aspect of this project.
‘If you want to move any agricultural product, you need to be aware of the most likely pathways for pests and diseases to come into countries, and the biosecurity treatments to mitigate those threats,’ said Dr Timote.
‘We want to help farmers, producers and exporters improve their ability to address some of the biosecurity threats and create opportunity to improve the value of coconuts.’
Dr Timote also reflected on the cultural significance of coconuts to his home country of Fiji, as well as other Pacific islands, where many people rely on coconuts for their livelihood.
‘From a young age I was taught to respect coconut trees because they give you everything you need: from coconut leaves to thatch your house, to coconut milk, to using the shells as cups to drink from. The coconut is the tree of life for all of us in the Pacific.
‘I would like my great-grandchildren to see and know what a coconut tree is because it’s not affected by a pest or threat that causes it to become obsolete.’
Approach to climate change
The future of the coconut industry, including breeding for climate resilience, was an important topic at the 50th international COCOTECH conference held in November 2022 in Kuala Lumpur, Malaysia.
The industry’s approach to climate change, appropriate policies, agronomic practice strategies and genetic development strategies were part of the discussion.
Dr Julianne Biddle, ACIAR director of multilateral engagement, having a background and continued interest in coconut research, attended the conference.
Coconuts are regularly grown in areas that are exposed to extreme weather events such as cyclones, typhoons, tsunamis and droughts. With climate change further aggravating these conditions, Dr Biddle noted that there appeared to be a common drive towards seeking new coconut varieties with more resilience to these conditions.
‘Some farmers are living and growing coconuts in areas that are becoming quite challenging at the moment, and some are not going to be able to stay where they are. We’ve already seen areas in Fiji where people have had to move due to constant water inundation,’ said Dr Biddle.
She said breeding for traits such as higher tolerance to water inundation and salt exposure are things that may be able to reduce the challenges created by changing climate conditions.
‘We’re looking at more extreme weather and ways we can create more tolerant varieties for these conditions is becoming a priority.’
Conserving and analysing coconut genetic resources will be a very important step in working towards more resilient varieties, and Dr Biddle is optimistic about the growing collaborative spirit in the coconut sector.
‘The network seems to be more connected than I have ever seen it over the years, more motivated,’ she said. ‘There’s a lot of people willing to collaborate and willing to find solutions and I’m hopeful that they will be successful in doing that: in sharing germplasm, protecting germplasm and then classifying it.’
The collaboration of Pacific island countries through this ACIAR-supported project aims to empower regional authorities and farmers alike with the resources and knowledge they need to protect this culturally and economically important crop. The project is expected to run until the end of 2025.