Technology

Arabica & Robusta, meet your new friend Brassii

In 1801 botanist, Robert Brown, joined Commander Matthew Flinders on the HMS Investigator for the first circumnavigation of Australia. On 2 November, 1802 the Investigator weighed anchor at Goods Island (Palilug Island) in the Torres Strait, allowing Brown to collect a rather insignificant and unknown plant belonging to the coffee family (Rubiaceae).  This same plant was collected again in 1821 by botanist and explorer, Allan Cunningham, from Sunday Island.  It was not seen again on Australian soil for 150 years until 1971 on the island of Dauan in the Torres Strait. Three years later, rainforest botanists, Len Webb and Geoff Tracey, found the same plant growing on a remote headland on the east coast of the Cape York Peninsula, near the mouth of the Pascoe River. In the meantime, this unknown plant was finally named as a new species, Paracoffea brassii, which later changed to Psilanthus brassii. Nearly four decades later, this plant would find itself the subject of discussion among the coffee industry at large, after taxonomic research undertaken earlier this year – led by Dr Aaron Davis at the Royal Botanic Gardens, Kew, in the United Kingdom – confirmed a close relationship between the coffee genus, Coffea and the genus Psilanthus. As it turns out, what Brown had discovered 209 years ago, was Australia’s first and only known indigenous coffee species. Scientists can now confirm that Psilanthus, which includes 20 or so species, is now accepted as part of the natural variation of coffee. Subsequently, to reflect the latest findings, this wild Australian coffee has been reclassified as Coffea brassii. Genetic analysis of C. brassii shows that it is closely related to the Asian coffee species, which in turn, are related to the all-important cultivated species, Robusta (C. canephora) and Arabica (C. arabica). Records show that Coffea brassii was collected in 1933 in the Central Province of Papua New Guinea.  However, it is possible that the plant was collected earlier and that specimens have languished in piles of unidentified specimens in herbaria. According to Professor Darren Crayn, Director of the Cairns-based Australian Tropical Herbarium at James Cook University and who is heading the Australian side of the research on C. brassii, the genetics of the Coffea genus and Psilanthus are very similar and the one thing they both have in common is that they possess coffee beans. Since the discovery, Crayn has spent four days on the Cape York Peninsula collecting fresh samples of the native species for further testing. Between 50 and 100 plants were found in a localised area. “The plants themselves don’t look anything like commercial coffee plants,” Crayn says. “They were found to be much smaller and they don’t produce as much fruit. We now know what the species is related to, but we don’t know what the beans contain or how the plant behaves ecologically or in cultivation.” It is thought the plant could be known to Indigenous tribes that inhabit the Cape York region, as Indigenous people elsewhere in the world use a number of wild coffee species as a stimulant.  Quite a few wild coffees are cultivated on a small scale and consumed locally, such as the Kafé kely species from Madagascar. Translated as “small coffee,” this plant contains tiny beans that are more or less caffeine free. Davis says this coffee is collected from the wild and consumed directly by the collectors or sometimes sold in local markets and roasted by the Indigenous community who seem to favour Kafé kely over Robusta. Roasters eager to sip this new bean, however, should hold off on warming their machines just yet. Scientists are yet to determine if the latest find even contains caffeine, but the new discovery is an exciting feat for the coffee industry and scientists alike. The scientific community has historically found that wild coffee species are critical for conservation and in the future these genetic resources are key to the long-term sustainability of coffee production. Naturally occurring Arabica coffee populations are already suffering from climate change and deforestation in Ethiopia, Sudan and Kenya, according to studies by Davis and co-researchers. Davis notes that it is no surprise that climate change is a contributing factor to the sharp rise in coffee prices. According to Davis, nearly 70 per cent of more than 100 coffee species found globally are threatened by extinction. Arabica coffee is considered vulnerable and it is possible that four species are already extinct.  When Arabica trees were first taken out of Ethiopia in the 1700s, they went on wooden sailing ships to be dispersed across the world. The end result of the long voyages was that few plants survived and our modern coffee crops are based on very low genetic diversity. This means that Arabica doesn’t have sufficient flexibility to deal with stress from disease and climate change. Davis says it is well documented that many coffee plantations are already suffering from climate change and increased pest attack and that in some areas plantations will disappear in as little as 10 years. “The industry must focus on the two crop species Arabica and Robusta,” Davis says. “In the long-term we should still be looking at the wild species, as you never know what potential you’ve got or what potentially valuable important species you might lose. Now that we know what the relatives of coffee are we can move forward and look at sustainability and conservation of its close relatives.” Through Davis’ research, he hopes to discover how Arabica, Robusta and other species, including C. brassii will deal with climate change. Davis has worked on coffee research for nearly 15 years with a particular focus on the wild coffee species of Madagascar, East Africa and Asia. Up to the 1950s, a lot was already known about wild coffee species, although from the 1960s onwards there has been a great acceleration in the knowledge of these plants. In 2001 Davis started a project that looked at the DNA and relationships of coffee species to each other, which subsequently lead to the discovery of the close relationship between Coffea and Psilanthus. Alongside this 21st Century approach, Davis adopted a traditional approach to exploration and discovery, which has changed little since Brown and Cunningham’s days in the early 1800s. Davis says he wants to find out how many wild coffee species exist and where they are found. To do this, rigorous botanical exploration is required. Understanding the fundamental information for a single species is also important.  According to Davis, Ethiopia still has an abundant wild population of Arabica coffee; some more adapted to drought, others to higher precipitation and some better able to deal with certain pests and diseases. In this way, wild coffee genetic diversity can be used to mitigate negative impacts and enhance the production of Arabica in plantations across the world. In terms of cross-breeding the C. brassii with commercial varieties, Davis says at this stage it’s almost “science fiction” to have this coffee involved in breeding programs. “It’s unlikely to happen in the short-term, but you just never know,” he says. “It’s not just about transferring genes. On the basis of the research from this plant, you might discover something about coffee which you didn’t know about before. It could be a chemical pathway that teaches us something about genetics, which could also be used in some way to enhance coffee production of the other species. We just don’t know what attributes this coffee might have. It’s about understanding the coffee genus and then this might give us some positive use for production.” Whether C. brassii has a future as a coffee producing plant or not, it’s discovery, Davis notes, teaches us how valuable our plant species are.  “If we don’t look after these things [coffee species] we’re basically reducing our spectrum of potential in the future,” he says. “If Arabica became extinct in the wild, the medium to long-term future of this crop species could become increasingly problematic. It is important to remember that around 75 per cent of the coffee produced globally is from Arabica and nearly all the coffee we drink in Australia is Arabica.” Thankfully for the coffee connoisseurs of the world Davis says we’re still going to be able to enjoy coffee for years to come.  “If we manage our wild coffee resources with care and due respect, it looks like Arabica is going to be safe until the end of the century. [Arabica] will have the potential to withstand climate change, however deforestation is more likely to be an issue than climate change over the next 100 years.” In the late 1990s a program of research was initiated by the Royal Botanic Gardens, Kew, to reinvestigate the diversity of coffees in Madagascar and selected areas of Africa, which included field research expeditions to explore rarely visited locations, particularly in Madagascar. Over the last 10 years, Davis and his co-researchers have discovered 21 new coffees, which is nearly a quarter of the species diversity for the genus. One of the most remarkable new species found includes the large fruited Ambongo (C. ambongensis) and Boina coffees (C. boinensis), which possess the world’s largest coffee beans. Since 2006, Kew has been carefully monitoring the conservation scenarios for all wild coffee species, using modern mapping technology in combination with historical distribution data from plant collection records and information on vegetation change. In situ conservation is extremely important for long-term survival of coffee species, as they cannot be stored in seed banks using conventional methods, requiring cryopreservation (storage in liquid nitrogen) or other laboratory based methods. Coffee germplasm can and is, being stored in field gene banks, which consist of living trees, cultivated under controlled conditions. However, field gene banks are costly and vulnerable to a wide range of hazards and the collections often suffer from genetic erosion. For wild populations of Arabica, one solution to reduce the effects of climate change and the potential threat of extinction from deforestation, is to plant more shade coffee in Ethiopia – a movement Davis sees as having considerable potential. The aim is to preserve the wild Arabica gene pool as well as the natural genetic diversity of other crop species. It would provide an income for local people, enhance biodiversity and offer a more realistic model of sustainability for the industry.  “It’s about thinking of an approach to conservation with tangible outcomes with local people and everyone involved in Arabica production,” Davis says. While funding these projects is costly and difficult, he believes in time it will happen. Already the United Nations has designated two protected areas in Ethiopia, which will help to preserve the natural genetic variation of Arabica.  Davis says the key to these projects is good planning and management. Arabica data and climate change predictions can be used to pinpoint reserve location and guide management and planning. In addition, coffee plantations should have the potential and flexibility to withstand a two-degree temperature rise by the end of the century. With the inclusion of Asian and Australasian species from Psilanthus, the Coffea genus now comprises 125 species. With species from Africa and Madagascar still requiring scientific names, the final number is likely to be nearer to 140. Our coffee crop species, Arabica, Robusta and Liberica (C. liberica) occur naturally in Africa, but they are outnumbered by the more than 100 other coffee species. According to Davis, Madagascar has 60 species of coffee, Africa 41, Asia 20, the Mascarenes Islands (Mauritius and reunion) three and Australia now has one. As scientists continue to discover and understand the wild coffee species of the world, the potential benefits for the coffee industry increase. New research is currently under way to determine the biochemistry of the C. brassii coffee bean. Crayn and colleagues will conduct chemical analyses of samples to discover its quality and flavour. Further tests will analyse whether the coffee beans are rich in caffeine or if they contain caffeine at all – a step towards knowing what the beans will taste like if they are roasted. “If the chemical analysis shows there’s nothing too toxic in the beans and the plant, then we’ll try roasting some and we can perhaps have our own brew,” Crayn says. Whether the beans turn out to produce a horrible flavour or make a delicious brew, Crayn says that taxonomy, the science of naming and classifying organisms, is an exciting field to be in. The latest discovery is symbolic of the vast unknown biodiversity within Australian and the world. “This new finding highlights the fact that there is a world of undiscovered species in the wild,” he says. “We don’t know what’s out there, not only in Australia, but in other countries. Over 200 new species of plants and fungi are discovered each year across Australia and many more globally. We’ve only scratched the surface of knowledge of our biodiversity, particularly in the tropics.”
Brassii, Arabica and Robusta may have several new cousins before the end of the century.

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