Genetic Diversity and Biochemical Quality Assessment of Romanian Maize Germplasm for Grain Quality Improvement

Maize (Zea mays L.) is a major cereal used for food, feed, and industrial applications. This study assessed genetic diversity and biochemical variability among 49 maize genotypes to identify promising material for grain quality improvement. RAPD profiles were used to calculate Jaccard similarity coefficients and construct the UPGMA dendrogram. Total nitrogen, crude protein, starch, crude fat, and β-carotene were measured using standardized ISO/EN ISO procedures, Soxhlet extraction, and spectrophotometry. RAPD markers generated 42 amplified DNA fragments, of which 39 were polymorphic. Mean RAPD PIC values ranged from 0.187 to 0.424, with OPC-2 showing the highest value. RAPD-based clustering suggested two main groups of genotypes. Biochemical traits varied significantly among genotypes, with genotype means ranging from 8.67 to 13.72 g/100 g for crude protein, 62.50 to 74.50 g/100 g for starch, 2.61 to 5.06 g/100 g for crude fat, and 0.55 to 1.32 mg/100 g for β-carotene. HSF hybrids exhibited higher mean crude fat and lower mean starch than commercial cultivars, while crude protein and β-carotene showed no significant differences at the genotype level. These analyses identified maize genotypes with promising grain composition for further breeding evaluation aimed at improving nutritional quality. Their responses to environmental stress and the stability of their grain composition require assessment in dedicated stress experiments and multi-environment trials.