About 7,000 years ago, bananas were not the soft, fleshy, seedless fruits we know today. The pulp was full of black seeds and was almost inedible. Instead, people ate the banana flowers or their underground tubers. They also extracted fibers from the trunk-shaped stem to make rope and clothing. Banana trees back then were “a far cry from the bananas we see in the fields today,” says Julie Sardos, a genetic resources scientist at the Alliance of Bioversity International, which stocks banana varieties, and I totally agree from what I have learned.
Scientists know that the predominant wild ancestor of the banana is a species called Musa acuminata, which is found from India to Australia. Most researchers agree that Papua New Guinea is where domesticated bananas as we know them first appeared. In fact, in Central America there is a small species of banana called guineo. Even though most experts agree on these facts, they disagree as to which species moved first, whether the Musa paradisiaca or kitchen banana (the one we use for mofongo and piononos) or the Musa sapientium or banana (the one we call in Puerto Rico guineo, and which we use for guineítos pickled).
The writings of the early 16th century confirm the arrival in the Caribbean, in 1516, of a species of muses. In his General and Natural History of the Indies (1535) the chronicler Gonzalo Fernández de Oviedo records that this specimen first arrived in Hispaniola, brought from the Canary Islands by the friar Tomás de Berlanga. It would have arrived in the Canary Islands in the 15th century, brought from Equatorial Guinea by Portuguese navigators.
In his History, Oviedo himself indicates that the Spanish during the conquest assigned the name banana to this species, ascribing to it – wrongly according to the chronicler – the name of the bush called banana or European shade banana (Platanus hispánica). In this regard, Fernández de Oviedo wrote: “[there is] a fruit that here [in Hispaniola] they call bananas; but in truth they are not, nor are these trees, nor were there any in these Indies, and they were brought to them; “But they have to stay with this inappropriate name for bananas.”
“The name plantain and the name banana were used interchangeably by dozens of travelers and explorers, Arabs and Europeans, from the Middle Ages until long after the discovery. That is why, in many European countries, they still call banana a plantain, that is, the fruit that in Puerto Rico we call banana; and plantain for eating or cooking plantain which we use for spiders and tostones”. According to food historian Cruz Miguel Cuadra.
“The name plantain and the name banana were used interchangeably by dozens of travelers and explorers, Arabs and Europeans, from the Middle Ages until long after the discovery. That is why, in many European countries, they still call banana a plantain, that is, the fruit that in Puerto Rico we call banana; and plantain for eating or cooking plantain which we use for spiders and tostones” adds Cruz.
Some researchers also disagree regarding the prehistoric and historical chronology, and their trajectories and movements towards regions of the Middle East, Europe, Africa and the Caribbean islands. There are even naturalists from the 16th and 17th centuries, as well as botanical geographers from the 19th century, who think that before the Spanish conquest there were species of muses in America that were “native” to some subtropical regions of the South American continent.
Today, there are many varieties of banana, more than 1,000 at last count. Over the course of their domestication, modern bananas available in supermarkets lost their seeds and became meatier and sweeter. But it has been difficult to pinpoint exactly how and when that domestication occurred. In this case, I think it’s safe to say that modification has been a good thing, similar to watermelons, I can go further on that in another post.
To complicate matters, some bananas have the usual two sets of (parental) chromosomes, while others have three sets or more, suggesting that at least some modern bananas are hybrids that resulted from crossing two or more varieties, or even different species.
There is good reason to try to tap into the deep historical gene pool of the modern banana: Today the $8 billion banana sector, which produces 100 billion bananas a year, is threatened by diseases such as Panama disease and bacterial wilt. banana.
Banana growers are scrambling to find ways to combat these pathogens, particularly those that attack the Cavendish banana, which accounts for more than half of all bananas exported to the United States and Europe. Some are collecting wild relatives and dark varieties that are more resistant to disease. But introducing genes from distant ancestors could also help strengthen modern bananas. Genetic analyzes can help reconstruct the history of domestication and pinpoint the living members of these ancestral fruits.
Nabila Yahiaoui, a banana genomics scientist at the French Agricultural Research Center for International Development in Montpellier, and her colleagues previously compared DNA from 24 samples collected from wild and domestic bananas. In some of them, they found something disconcerting: DNA that didn’t match any of the other samples. Based on that finding, they proposed in 2020 that, in addition to M. acuminata and other known wild relatives, two unknown species contributed DNA to the modern banana.
Nabila Yahiaoui, a banana genomics scientist at the French Agricultural Research Center for International Development in Montpellier, and her colleagues previously compared DNA from 24 samples collected from wild and domestic bananas.
In the new study, Sardos and his colleagues expanded on that work, focusing on banana varieties with two sets of chromosomes, as they are likely most closely related to early domesticated bananas. (The Cavendish has three sets of chromosomes).
They sampled the DNA of 68 samples of wild relatives and 154 types of cultivated bananas, including 25 varieties that Sardos’ team collected in Papua New Guinea.
The comparison provided further evidence that bananas were originally grown in New Guinea and suggested that a subspecies of M. acuminata called “banksia” was the first to be domesticated. The same subspecies later contributed to more widespread cultivated varieties, Sardos and colleagues report this month in Frontiers in Plant Science. “This [conclusion] is significant,” says Denham. “It confirms previous archaeological, botanical, linguistic and genetic studies.”
The samples also pointed to the existence of a third, unknown source of banana genetic material, the team reported. Scientists have yet to identify all three species; Their data suggests that one came from New Guinea, one from the Gulf of Thailand, and the third from somewhere between northern Borneo and the Philippines.
Denham was surprised to discover that modern banana varieties in New Guinea are more genetically diverse than their wild ancestor. “This goes against most genetic arguments that speculate that initial domestication results in a bottleneck,” he says. He suspects that even as banana growers worked to improve bananas, there was rampant interbreeding with wild relatives, leading to clusters of varieties with different genetic ancestors.
“This work further confirms the importance of hybridization in the evolution of [certain] crops,” says Rieseberg, whose work with sunflowers has shown that interbreeding can be important for evolution.
The field remains full of possibilities: Sardinians and other banana fans hope to visit small farms and other sites in the ancestral banana lands to see if they can find more modern descendants. They can also produce disease-resistant stock that can be crossed with commercial bananas. “There is a lot of unsampled banana diversity,” says Loren Rieseberg, evolutionary biologist at the University of British Columbia, Vancouver.