Abstract
Understanding how farmers name and categorize their crops in relation to the way they propagate them is critical for a proper assessment of agrobiodiversity. Yet, indigenous knowledge is often overlooked in genetic studies which may result in an underestimation of crop diversity preventing its conservation and mobilization for developing sustainable agrosystem.Here, we study the status of the barnī date palm, the local elite variety of the oasis of al-‘Ulā, Saudi Arabia. We conducted an ethnobotanical survey on local phoeniculture practices and generated whole-genome data to determine whether or not barnī palms are exclusively clonally propagated. Further, we contrasted the genomes of barnī and two other palms from al-‘Ulā with 112 Phoenix spp. to provide a first insight into the origin of date palm diversity in this millennia-old oasis.Results show that behind the name barnī lies a single clone line, a true-to-type cultivar, indicating clonal propagation by offshoots with name maintenance even between distinct cultivating situations in al-Ulā and a nearby oasis. Nonetheless, it is distinct from the prominent barnī cultivated in Oman. Its ancestry is comparable to other West Asian date palms but we found that the ancestry of another palm from this oasis shows influence from North African date palm.What lies behind the cultivar name barnī in al-‘Ulā and further afield in the Arabian Peninsula has been deciphered through the key disciplinary combination of social anthropology and genetics. Future studies will provide additional insights into the original genetic make-up of this oasis.