Morphological and Genetic Characterization of Local Maize Accessions from Emilia Romagna Region, Italy

Italian maize germplasm is particularly rich in local materials and each region is characterized by the presence of peculiar local varieties deriving from centuries of adaptation, selection and cultivation. While the introduction of hybrids, during the 1950s, led to the disappearing of many of these varieties, some have been maintained in cultivation by farmers, frequently in marginal areas, as a kind of family heritage. Local varieties were identified throughout field surveys carried out in recent years. The discovery of a traditional popcorn variety over the most common flint and semi-flint materials used for production of polenta was interesting. Since these varieties have never been adequately described and reported in scientific literature, this study was aimed to solve this lack of knowledge on recently discovered local maize populations. Characterization represents the first step of a process focused on the preservation and possible exploitation of important genetic resources. Traditional materials are a useful reservoir of genes for adaptation to local conditions and climate changes. Adequate breeding programs can use such germplasm for developing new and more resilient varieties. These local materials have been characterized at the morphological level highlighting plant, ear and kernel differences. Genetic characterization, carried out on 455 individuals by the use of 10 SSR markers, revealed 62 different alleles ranging from four for markers phi127, phi076 and phi084 to nine for marker p-bnlg176 . The landraces are well distinguishable at genetic level since 40% of genetic variability is present among accessions. Five landraces are characterized by the presence of private alleles and heterozygosity levels are generally good. These findings support the possibility to correctly preserve local materials through in situ conservation. Phylogenetic analysis evidenced the presence of varietal clusters, the clearest one formed by three red-pigmented accessions. STRUCTURE analysis revealed that five landraces have a well-defined genetic attribution while the remaining two (EMR04-Mais Rosso di Rasora and EMR10-Mais del Principe di Scavolino) are both constituted by two different backgrounds.