Study of an ancient maize from Valcamonica (northern Italy) rich in carotenoids and 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. Furthermore the detailed characterization of these ancient cultivars will allow the correct conservation of these open pollinated varieties (opvs) necessary for assessing their value and for further studies. In this work we characterized the ancient pigmented “mais nero spinoso di Vallecamonica”. A preliminary spectrophotometric analysis revealed the presence of flavonols, phenolic acids and in particular phlobaphenes, probably responsible for the ear coloration: further investigations to better characterize this pigment by HPLC are in progress. 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 P1 gene in this landrace and histological analysis confirmed that the pigment is accumulated in the pericarp. In the mean time HPLC analyses showed also the presence of a big amount of carotenoids and probably thanks to the high amount of pigments, this maize variety showed a very high antioxidant ability. Given the chronic disease prevention property of the antioxidant molecules, this variety could become very interesting also by a nutritional point of view. This characterization will allow an accurate description of this landrace with the aim to study and preserve the maize biodiversity in Europe and in particular in Italy. We are collaborating with the municipality of Esine and Piancogno to the application process needed to register this ancient cultivar to the National Register of conservation varieties with the aim to valorize this ancient landrace.