Sixteenth-century tomatoes in Europe: who saw them, what they looked like, and where they came from

Abstract

Background: Soon after the Spanish conquest of the Americas, the first tomatoes were presented as curiosities to the European elite and drew the attention of sixteenth-century Italian naturalists. Despite of their scientific interest in this New World crop, most Renaissance botanists did not specify where these 'golden apples' or 'pomi d'oro' came from. The debate on the first European tomatoes and their origin is often hindered by erroneous dating, botanical misidentifications and inaccessible historical sources. The discovery of a tomato specimen in the sixteenth-century 'En Tibi herbarium' kept at Leiden, the Netherlands, triggered research on its geographical provenance and morphological comparison to other tomato specimens and illustrations from the same time period.

Methods: Recent digitization efforts greatly facilitate research on historic botanical sources. Here we provide an overview of the ten remaining sixteenth-century tomato specimens, early descriptions and 13 illustrations. Several were never published before, revealing what these tomatoes looked like, who saw them, and where they came from. We compare our historical findings with recent molecular research on the chloroplast and nuclear DNA of the 'En Tibi' specimen.

Results: Our survey shows that the earliest tomatoes in Europe came in a much wider variety of colors, shapes and sizes than previously thought, with both simple and fasciated flowers, round and segmented fruits. Pietro Andrea Matthioli gave the first description of a tomato in 1544, and the oldest specimens were collected by Ulisse Aldrovandi and Francesco Petrollini in c. 1551, possibly from plants grown in the Pisa botanical garden by their teacher Luca Ghini. The oldest tomato illustrations were made in Germany and Switzerland in the early 1550s, but the Flemish Rembert Dodoens published the first image in 1553. The names of early tomatoes in contemporary manuscripts suggest both a Mexican and a Peruvian origin. The 'En Tibi' specimen was collected by Petrollini around 1558 and thus is not the oldest extant tomato. Recent molecular research on the ancient nuclear and chloroplast DNA of the En Tibi specimen clearly shows that it was a fully domesticated tomato, and genetically close to three Mexican landraces and two Peruvian specimens that probably also had a Mesoamerican origin. Molecular research on the other sixteenth-century tomato specimens may reveal other patterns of genetic similarity, past selection processes, and geographic origin. Clues on the 'historic' taste and pest resistance of the sixteenth-century tomatoes will be difficult to predict from their degraded DNA, but should be rather sought in those landraces in Central and South America that are genetically close to them. The indigenous farmers growing these traditional varieties should be supported to conserve these heirloom varieties in-situ.

Keywords: 16th century; Botanical illustrations; Colonial history; Crop diversity; Historical herbaria; Landraces; New World crops; Renaissance; Solanum lycopersicum; Tomato.

Figure 1. All extant specimens of tomatoes in sixteenth-century herbaria, in chronological order.

(A) Ulisse Aldrovandi (c. 1551), Vol 1, p. 368. The pair of leaves at the bottom of the page belong to a Citrullus. Photo credit: University of Bologna. (B) Francesco Petrollini (pre-1553) Photo credit: Biblioteca Angelica, Rome, c.49r, Erbario Cibo B, vol. 3. (C) Francesco Petrollini (c. 1558), L.2111092, ‘En Tibi tomato’. Photo credit: Naturalis, Leiden. (D) Leonhard Rauwolf (1563), Photo credit: Naturalis, Leiden. (E) Caspar Bauhin (1577-1624) B15-075.2A. Photo credit: Herbaria Basel, University of Basel. (F) Bauhin B15-075.2B_1. Photo credit: Herbaria Basel, University of Basel. (G) Bauhin B15-075.2B_2. Photo credit: Herbaria Basel, University of Basel. (H) Hieronymous Harder (1576–1594), Photo credit: Bayerische Staatsbibliothek München, Cod.icon. 3, fol. 140v. (I) Ducale Estense herbarium (1570–1580), Photo credit: Archivio di Stato di Modena. (J) Caspar Ratzenberger (1592), Photo credit: Naturkundemuseum Kassel. Written permission to publish these images is provided in Fig. S3 .

Figure 2. Published and unpublished 16th century tomato illustrations, in chronological order.

(A) Dodoens (1553), (B) Dodoens (1554), (C) Gesner (1553), image credit: Universitätsbibliothek der FAU Erlangen-Nürnberg, MS 2386, 37v, (D) Gesner manuscript (1553), image credit: Universitätsbibliothek der FAU Erlangen-Nürnberg, MS 2386, 42r, (E) Fuchs (1549–1556–1561), image credit: Österreichische Nationalbibliothek, (F) Domenico Dalle Greche/Michiel (1550–1576), image credit: Biblioteca Marciana, (G) Oellinger manuscript (1553: 541), image credit: Universitätsbibliothek der FAU Erlangen-Nürnberg, MS 2362, 541, (H) Oellinger (1553: 543), image credit: Universitätsbibliothek der FAU Erlangen-Nürnberg, MS 2362, 543, (I) Oellinger (1553: 545), image credit: Universitätsbibliothek der FAU Erlangen-Nürnberg, MS 2362, 545, (J) Libri Picturati (1565–1569) A f(olio) 81r, image credit: Jagiellonian library, (K) Libri Picturati A 28 f(olio) 81v, image credit: Jagiellonian library, (L) De Lobel (1572), (M) Camerarius (1586: 821), (N) Camerarius, 1590: 378), (O) Bauhin (1598). Written permission to publish these images is provided in Fig. S3.

Figure 3. Results of the Neighbor Net clustering analysis, showing the genetic similarity of the wild relatives and the domesticated tomato specimens analyzed by Michels (2020).

(A) Wild individuals of S. pimpinellifolium and S. lycopersicum L. var. cerasiforme from Peru (green circles) and Ecuador (bright green circles) show a high genetic diversity (left of the figure), while a dense cluster of domesticated, genetically less diverse tomatoes is visible on the right, which includes the En Tibi specimen. (B) Enlargement of the cluster with domesticated tomatoes from Fig. 3A, showing the nearest neighbors of the En Tibi tomato (gray circle). All distances expressed in Kimura 2-parameter substitutional distance; parsimony-uninformative SNPs excluded.