Morphological characterization of the genetic resources of Moroccan white mulberry (Morus alba L.)

The White mulberry (Morus alba L.), also known as "Toot" in Arabic, is a member of the Moraceae family. The leaves of the white mulberry, which is widely grown all over the world, are the main food source for silkworms. It is cultivated for its fruit in North African nations, and it is also eaten as a vegetable in some European countries. The leaves are used to make tea and powdered juice in Japan. The plant's fruits, leaves, roots, branches, and bark are all used in traditional medical systems, for their potential to promote health and provide antioxidants.

White mulberry is abundant in bioactive compounds, including phenolic acids, flavonoids, flavanols, anthocyanins, as well as essential macronutrients, vitamins, minerals, and aromatic volatile compounds. These naturally occurring substances exhibit potent biological activity and provide notable pharmacological benefits in the prevention and treatment of various diseases.

This work characterised and assessed phenotypic variation within this species. Forty-four qualitative and quantitative morphological characters pertaining to the tree, flowers, and fruit were evaluated across thirteen natural accessions sampled throughout its native Moroccan range. Significant intraspecific phenotypic variability was indicated by the analysis of variance, which showed significant variations between accessions for most characteristics. Moreover, the principal component analysis allowed for the classification of M. alba accessions into three distinct morphological categories. These observations reveal a great phenotypic diversity among the natural specimens of this species in Morocco. The study highlighted the phenotypic diversity that could serve as an attractive approach to consider the valorisation of this species in Morocco.