Histochemical Analysis and Protein Content of Maize Landraces (Zea mays L.)

Maize (Zea mays L.) has a wide range of food and non-food applications and is predominantly composed of carbohydrates, mostly in the form of starch, with considerable amounts of protein, as well as some lipids, vitamins and minerals. Both genetic and environmental effects create significant variation in the amount and quality of each of these constituents. Despite the fact that modern agricultural systems have greatly increased the yield of maize with modern cultivars, human domination of earths ecosystems is markedly reducing the biodiversity. To access the potential of Brazilian germplasm, seeds of eight maize landraces differing in their phenotypes were cultivated in Anchieta (trial 1) and Ressacada Research Farm, Florianopolis (trial 2) under a low input agricultural system. Alterations in primary metabolite (structural and reserve polysaccharides) were investigated by histochemical analysis and quantified the protein content. Significant protein contents were correlated with regional climatic conditions, cultivars and management practices. Samples of maize landraces of F0 progeny reacted more intensively to Toluidine Blue, Periodic Acid-Schiff and Coomassie Brilliant Blue, suggesting the occurrence of a higher content of acidic polysaccharides, starch, cellulose and proteins in that materials. F0 progeny showed high levels of proteins (e.g., LP and RX varieties). These results, together with our previous observations, confirmed the chemical diversity of maize landraces and can be more prospected to produce protein-rich derivatives due to the concerns on plant resources, biodiversity conservation contributing to local and global food security.