Back to beaked: Zea mays subsp. mays Rostrata Group in northern Italy, refugia and revival of open-pollinated maize landraces in an intensive cropping system

Abstract

Crop landraces are fundamental resources to increase the eroded genepool of modern crops in order to adapt agriculture to future challenges; plus, they are of immeasurable heritage and cultural value. Between the 1940s and the 1960s open-pollinated varieties (OPVs) of flint and semi-flint maize in Europe were almost completely replaced by high-yielding hybrid dent cultivars selected in North America. No comprehensive assessment was performed after the 1950s to understand which maize genetic resources survived genetic erosion in northern Italy, an area characterized by a high degree of landraces extinction and introgression, intensive hybrid dent monocultures, as well as being one of the hotspots of maize cultivation at a continental level. Among these landraces, beaked maize represents a peculiar case study for assessing the survival of OPVs in intensive cropping systems. By means of ethnobotanical and literature surveys, the history of Zea mays subsp. mays Rostrata Group and its current distribution were reconstructed. It emerged that beaked maize originated in the study area and it is one of the oldest genepools available not subjected to formal crop improvement. We identified 28 landraces of beaked maize currently cultivated, 18 here recorded for the first time. The cultivation of more than half of the 28 landraces has continued throughout the last 80 years in a few fragmented localities that can be regarded as “refugia”. The survival of these landraces from substitution with high-yielding cultivars and unidirectional introgression has been mainly due to active on-farm conservation performed by custodian farmers and secondarily to cultivation in isolated areas (e.g., mountain valleys). After decades of genetic erosion, beaked maize has since the late 1990s experienced a revival, in terms of an increasing number of cultivation localities and the level of product commercialization. This process is mostly spontaneous and only occasionally mediated by governmental institutions; it is linked to the rediscovery of local food products, in this case mainly polenta, a dish made of corn flour, which used to be the staple food across northern Italy. The ex situ conservation of beaked maize and on-farm measures put in place by the farmers to prevent introgression are also assessed. Further research and collecting missions are needed to provide an inventory of open-pollinated landraces of other landrace groups that have survived genetic erosion in Europe. To meet this aim, extensive ethnobotanical surveys, such as the one performed here, are very powerful tools in detecting these genetic resources.

Hidden Rice Diversity in the Guianas

“…Not a single restaurant in Cayenne or Paramaribo sells Maroon rice dishes. Given the increased interest by global consumers in traditional food products (Ardenghi et al, 2018), a greater awareness of the unique Maroon rice varieties could stimulate their conservation in the face of increased urbanization and outside pressures. An appreciation of the role of Maroons as custodians of rice diversity would benefit not just local food security, but also safeguard a precious global resource.…”

“…Wild relatives of rice and traditional landraces often show adaptations towards marginal environments and pest resistance and are therefore considered as an untapped genetic resource for breeding new cultivars resilient to future challenges (Alvarez et al, 2007; Wang et al, 2018). Landraces are also of key importance in local food security and preserving cultural heritage (Perales et al, 2005; Ardenghi et al, 2018), and reveal past migration patterns of humans and their contacts with outsiders (Westengen et al, 2014). Over the last few decades, a severe genetic erosion of crops has taken place due to the replacement of landraces by modern cultivars (Zeven, 1998; Dyer et al, 2014).…”

“…Much effort has been made to safeguard landraces ex situ (in gene banks) to make their genetic resources available for breeders, but the in situ conservation of agrodiversity within traditional farming systems has not been pursued to the same extent (Maxted et al, 2002). Ethnobotanical inventories are powerful tools in detecting these neglected genetic resources and understanding the social and cultural factors involved in generating and maintaining their diversity and distribution (Westengen et al, 2014; Ardenghi et al, 2018). Here, we describe the rice landraces that are grown by Maroons, descendants of escaped slaves in Suriname and French Guiana and discuss their efforts and motivations to maintain this diversity.…”

Hidden Rice Diversity in the Guianas

“…Landraces are also of key importance in local food security and preserving cultural heritage (Perales et al, 2005;Ardenghi et al, 2018), and reveal past migration patterns of humans and their contacts with outsiders (Westengen et al, 2014). Over the last few decades, a severe genetic erosion of crops has taken place due to the replacement of landraces by modern cultivars.…”

“…Much effort has been made to safeguard landraces ex situ (in gene banks) to make their genetic resources available for breeders, but the in situ conservation of agrodiversity within traditional farming systems has not been pursued to the same extent (Maxted et al, 2002). Ethnobotanical inventories are powerful tools in detecting these neglected genetic resources and understanding the social and cultural factors involved in generating and maintaining their diversity and distribution (Westengen et al, 2014;Ardenghi et al 2018). Here we describe the rice landraces that are grown by Maroons, descendants of escaped slaves in Suriname and French Guiana and discuss their efforts and motivations to maintain this diversity.…”