Study and valorisation of an ancient maize from Northern Italy rich in phlobaphenes

After the discovery of the Americas, maize cultivation became diffused in Europe and elsewhere around the world where hundreds of different landraces have been used to feed the local populations. However in the second half of the last century the American dent hybrids began to be widely grown, leading to the disappearance or marginalization of the less productive traditional varieties. Nowadays the characterization of traditional landraces can help breeders to discover precious alleles that could be useful for modern genetic improvement. In this research we characterized the ancient pigmented “Mais Nero Spinoso” from Valcamonica (Northern Italy). A preliminary spectrophotometric analysis revealed the presence of flavonols, phenolic acids and in particular phlobaphenes, probably responsible for the ear coloration. Phlobaphenes are reddish insoluble substances synthesized in maize through the flavonoids pathway by the polymerization of the flavan-4-ols. In maize this pigment is due to the presence of the pericarp1 gene (p1), a transcription factor belonging to the MYB gene family driving the accumulation of this pigment in the pericarp layer. The genetic and molecular analysis confirmed the presence of the P1gene in this landrace and histological analysis confirmed that the pigment is accumulated in the pericarp. Given the chronic disease prevention property of the antioxidant molecules (phlobaphenes), this variety could become very interesting also by a nutritional point of view. In December 2015, this landrace was included in the National Register of conservation varieties with the aim to safeguard and promote its cultivation.