Genome size and chromosome number for six taxa of<i>Origanum</i>genus from Morocco

Abstract

The majority of the Origanum species are important medicinal plants as well as culinary herbs and have thus a great economic value. Some taxonomic issues are still pending within the genus and the cytogenetic studies about this genus are still very scarce. Therefore, studies concerning chromosome number and genome size can provide complementary data that may be useful to characterize the genus Origanum. These two approaches have been used to characterize five Moroccan taxa of the genus Origanum occurring in the wild in addition to the exotic species O. onites. All investigated taxa are diploid with chromosome number of 2n = 30. This is the first time the chromosome numbers have been counted in O. grosii, O. compactum and O. × font-queri as well as in O. vulgare subsp. virens from Morocco. The genome sizes are considered as small, and the mean values ranged from 1.43 pg/2C in O. vulgare subsp. virens to 1.53 pg/2C in O. compactum. Besides, no significant intraspecific variability in genome size was observed among populations of O. elongatum as well as of O. grosii.