Steamed basmati rice and hammour with a side of dates is a staple meal around the Arabian Gulf. It represents the combination of local ingredients on offer in the harsh environment and highlights the intensive trade that allowed for faraway ingredients to become mainstays of the Arab kitchen. But research at NYU Abu Dhabi has now exposed the genetic complexity of each of the individual ingredients as more than the singular variety they were once thought to be.
Basmati rice is the most commonly consumed carbohydrate for residents of the Gulf and hundreds of millions of others around Asia. Muslim traders, who coveted the variety’s slender grain and fragrance, first introduced this rice from the Indian sub-continent some 300 years ago. It’s so prevalent today that the national dish of many countries in the region includes basmati rice, an ingredient that cannot grow in the Arabian Peninsula’s desert environment.
Despite the economic and cultural importance of Basmati and related aromatic rice varieties, their evolutionary history is not fully understood. Now, researchers from NYU’s Center for Genomics and Systems Biology, which is partially funded by NYUAD, assembled the complete genetic blueprint of basmati rice, showing that basmati rice is actually a hybrid of two other rice groups.
Using innovative genome sequencing technology, the researchers discovered that most genetic material in Basmati comes from japonica (a rice group found in East Asia), followed by the rice group aus (found in Bangladesh).
Now that the genome sequences of basmati rice have been established, the researchers aim to work with the scientific and rice breeding communities to identify important genes, see what makes the Basmati group unique, and even develop molecular markers to help breed new varieties.
Divers who have seen hammour in its natural habit note the fish’s sheepish disposition as it hovers on the Arabian Gulf’s sandy seabed hiding from predators and bate alike. Its reluctance to expose itself has challenged fishermen for centuries and now it seems that secretiveness has expressed itself in the grouper’s genes.
As one of the most sought after eating fish, hammour is commonly sold around markets in the Middle East – often it’s advertised as one species. But research from NYUAD shows that the fish commonly thought of as one species is actually three.
The researchers at NYUAD sequenced mitochondrial DNA from 140 tissue samples collected in four fish markets and analyzed the data to reveal the presence of three distinct Epinephelus species being marketed and sold as one: hammour. In fact, the hammour on sale in the UAE is not only Epinephelus coioides, but also Epinephelus areolatus and Epinephelus bleekeri.
According to NYUAD associate professor of biology John Burt, “This was the first application in the Gulf of genetic approaches to hammour, one of the most highly valued fish species in the region. The results were highly informative in showing us that what is being marketed as a single species — hammour — is actually three separate species. These species look similar, but are genetically distinct from one another. This has important implications for fisheries management, as earlier management efforts, which had assumed there was just one species, need to be broadened to account for possible differences in the biology of these three species.”
Youssef Idaghdour, NYUAD assistant professor of biology, said, "This work provides a much needed snapshot of the genetic makeup of grouper species in the UAE. With the rates of climate change, overexploitation and other environmental pressures in the region, biodiversity and genetic variation of marine species are under severe threat. These findings reinforce the importance of genetic monitoring for sustainable management practices."
Records from early life in the region show local Bedouins subsisting for weeks, if not months on end, on nothing but camel milk and dates. The superfruit is packed with nutrition, easily consumed and easily transportable. In fact, it travels so well that seeds from as far away as Crete and Turkey mixed with local date palms to create the Middle Eastern varieties that are so prevalent today.
To solve the mystery of the origin of North African date palms, the researchers at NYUAD working with colleagues from NYU in New York and others around the world, sequenced the genomes of a large sample of date palms from Middle East, North Africa and South Asia, as well as palms from related but distinct wild species.
The genome analysis found that hybridization between date palms and P. theophrasti, a species known as the Cretan wild palm found in the Eastern Mediterranean, is the source of the mixed ancestry and genetic distinction of North African date palms.
Genome analysis reveals that North African date palms are a hybrid between cultivated date palms from the Middle East and a different, wild species of palm that grows on the island of Crete and in small areas of Southern Turkey.
These findings, the result of research at NYU Abu Dhabi’s Center for Genomics and Systems Biology (NYUAD CGSB), shed new light on the evolutionary history of one of the earliest domesticated tree crops in the world, which remains a major fruit crop in North Africa and the Middle East.
Previous studies have shown that while dates from the Middle East and North Africa belong to one species – Phoenix dactylifera – the date palms from these two regions are genetically different. The distinct nature of North African dates, which include such popular date varieties as Medjool and Deglet Noor, has led to questions as to how they originated. There have been suggestions, for example, that North African date palms may have been domesticated independently from date palms in the Middle East.
Rice, hammour and dates is a complete meal that represents the variety of ingredients on offer, some from the land but mostly from trade. The importance of understanding the genetic depth of these ingredients is more important today than ever, as genetically modified crops and aquaculture gains traction. Research from NYU Abu Dhabi and its network will continue delving into the essence of all that is eaten for granted.