Microsatellites, morphological, and alkaloids characterization of Zephyranthes fosteri and Z. alba (Amaryllidaceae): Allopatric populations

Zephyranthes (Amaryllidaceae) is a taxonomically complex genus due to the frequent overlap of interspecific morphological variation. In Mexico, Z. alba and Z. fosteri are herbaceous plants that, when distributed in sympatry, generate individuals with complex patterns of morphological variation, leading to taxonomic confusion. Therefore, it is necessary to first characterize these species in allopatric populations. In this contribution, molecular, morphological, and alkaloid profiles were used to characterize both species in allopatric sites. Our results show that Z. alba and Z. fosteri allopatric populations are two well-defined genetic and morphological groups. Flower-related characters were the ones that best allowed us to distinguish between species. In a similar fashion, the alkaloid profile showed remarkable differences among species: four alkaloids were specific to Z. alba and five to Z. fosteri. Lycorine (43.3-88.8%) and galanthamine (87.7-91.4%) were the most abundant alkaloids for each species, respectively. In conclusion, Z. fosteri and Z. alba exhibit noticeable differences when distributed in allopatry. In addition, Z. fosteri has greater genetic and phenotypic plasticity compared to Z. alba, which could be related to the former's ability to colonize new habitats. Finally, the molecular, genetic and chemical markers developed here will provide a framework to further studies aiming to explore if hybridization among Z. alba and Z. fosteri occurs in sympatric populations. •Differences between Zephyranthes fosteri and Z. alba was determined in allopatric populations.•Z. fosteri and Z. alba are two well-defined genetic groups.•Their alkaloid profile is different between species.•Floral morphological characters allowed a clear distinction between species.