Maize introduction into Europe: the history reviewed in the light of molecular data

Abstract

The resolution that can be obtained from molecular genetic markers affords new prospects for understanding the dispersion of agricultural species from their primary origin centres. In order to study the introduction and the dispersion of maize in Europe, we have characterised a large and representative set of maize populations of both American and European origins for their variation at 29 restriction fragment length polymorphism loci. Polymorphism was higher for American populations than for European populations (respectively, 12.3 and 9.6 alleles per locus, on average), and only a few alleles were specific to European populations. Investigation of genetic similarity between populations from both continents made it possible to identify various types of American maize introduced into Europe at different times or in different places and which have given rise to distinctive European races. Beyond confirming the importance of Caribbean germplasm, the first maize type to be introduced into Europe, this research revealed that introductions of Northern American flint populations have played a key role in the adaptation of maize to the European climate. According to a detailed historical investigation, the introduction of these populations must have occurred shortly after the discovery of the New World.

Association mapping for phenology and plant architecture in maize shows higher power for developmental traits compared with growth influenced traits

“…They have cylindrical ears with 14-22 kernel rows and no tillers (Doebley et al, 1988). Diffusion of maize outside America led to additional races like European Flints that recombine genomes from Northern America and tropical origins (Rebourg et al, 2003).…”

Genetic diversity of the floury race of maize Avati Morotî from the Guaraní tribe in Paraguay

“…As a consequence, most of the autochthonous maize races hybridized and loosed their peculiarities so deeply that we 2 realized that maize was an interesting crop and introduced the new grain into Spain, Portugal and the Old World. Most authors believe that the origins of such introductions were mainly the Caribbean area and North America (Revilla et al, 1998(Revilla et al, , 2003Rebourg et al, 2003).…”

“…Indeed, some of the comprehensive studies of maize germplasm paid little or null attention to South-American genetic resources; e.g. Vigouroux et al (2008) only included five entries from Paraguay, and Rebourg et al (2003) completely skipped maize from this country. However, some of those germplasm pools could provide decisive information about the historical relationships and the potential inputs that we can still expect from unexplored variability.…”

Divergence in behaviour between the European corn borer,Ostrinia nubilalis, and its sibling speciesOstrinia scapulalis: adaptation to human harvesting?

“…Ostrinia nubilalis (the European corn borer, ECB) is a cosmopolitan pest of maize (Zea mays L.). It first appeared after the introduction of maize to Western Europe, approximately 500 years ago (Rebourg et al 2003) and was accidentally introduced in the Americas in the early twentieth century (Thompson & Parker 1928). The ECB is thought to have originated from O. scapulalis, its extant closest relative, which is sympatric with ECB in Europe but does not feed on maize: its main host plant is mugwort (Artemisia vulgaris L., Bourguet et al 2000;Malausa et al 2007a).…”