Analysis of ‘Marrakesh limetta’ (Citrus × limon var. limetta (Risso) Ollitrault, Curk & R.Krueger) horticultural history and relationships with limes and lemons

Abstract

Citrus (Rutaceae) species have a relevant role in the culture of the Mediterranean countries, not only for their gastronomic or medicinal value, but especially for their ornamental and symbolic importance. The interest on Citrus diversity led to collect and cultivate numerous cultivars around the Mediterranean Sea, at least since the Roman period. Their image is documented in mosaics, paintings, sculptures and coins since the first millennium BC. Among these, sweet and sour limettas Citrus × limon var. limetta (Risso) Ollitrault, Curk & R.Krueger stand for their history and conservation status. Presently sour limetta is cultivated in Morocco, especially in Marrakesh, and in the Valle de Ricote (Murcia, Spain). Our work has three main objectives: to characterize sour limetta on the basis of Spanish and Moroccan populations, as well as its cultural relevance throughout history, especially in painting, gastronomy, agriculture and gardening, to determine their relationships with limes and lemons and to evaluate the availability and state of conservation of that legacy.We analyze and illustrate the morphology of the plant, flowers and fruits of sour limetta and their differences with other related citrus species and cultivars: sweet limetta, lemon, common lime, Persian lime, bergamot, mellarosa, Meyer lemon, rough lemon, Pursha Romana lime, Palestine sweet lime, Pomum Adami lemon and Rangpur lime. The above species and cultivars were selected on the base of their known ancestry and pomological characters. The distinctive characters are useful for the identification of sour limetta in the field but also for the identifying images of this plant in paintings. We analyzed the ancestry of the different taxa involved and compared the classification based on phenotypes with the classification based on the proportion of ancestors’ genomes in each individual taxa. The image of sour limetta appears in different paintings, from the van Eyck's Ghent Polyptych (early 15th century), and numerous still life works by Italian and Spanish authors of the 16th to 18th centuries. A peculiar type of evidence is provided by presence of limetta in the pictorial catalogues of the Medici's fruit collections displayed in a series of paintings by Bartolomeo Bimbi.This distinctly sour limetta is sold in the markets of Rabat (and other cities of Morocco), either fresh, candied or brined and canned. It is an important ingredient of traditional Moroccan cuisine. Although sour lime was a widely used ingredient in Italian cuisine during the 17th century, its state of preservation is deplorable outside of Morocco, and even there it is gradually replaced by lemons. We recommend its cultivation as a resource both for obtaining rootstocks as well as for its fruits, both for Moroccan cuisine and that of other parts of the world for the excellent aromas and flavors that they contribute to the dishes. In this way, by promoting its crop, we will prevent it from disappearing. It is also important to preserve sour lime in germplasm banks.