ChroMorocco: the first georeferenced chromosome-number database for the Flora of Morocco, with initial coverage of the Asteraceae family

The chromosome number data of Asteraceae in Morocco have been compiled into a pioneering online database, establishing the first platform dedicated to georeferenced chromosome numbers in both Morocco and the African continent. The accumulation of cytogenetic data since 1957 needed the development of a comprehensive database to facilitate access to chromosome numbers and to provide associated metadata. The resulting database, accessible at https://www.chromorocco.com/ , is designed to accommodate chromosome-number data for the entire Moroccan vascular flora; in this first release, Asteraceae are presented as a case study to illustrate the database’s structure and functionalities. The dataset was meticulously assembled from 866 records extracted from 32 published articles and two books, encompassing 276 species and subspecies (36% of the 762 recognized taxa) and 40 genera (28% of the 141 known genera). Chromosome counts range from 2n = 6 to 2n = 64, with 2n = 18 being the most frequent. Among the studied genera, Centaurea is the most thoroughly investigated karyologically, with 21 taxa representing 30% of the 77 Moroccan species and subspecies. B-chromosomes were recorded in seven taxa (2.5% of the available data), occurring across arid, semi-arid, and Saharan bioclimatic zones and varying from one to two in number. This comprehensive resource provides an invaluable foundation for further research on the chromosomal dynamics and diversity of Moroccan Asteraceae.