University of Debrecen Centre for Agricultural and Applied Economic Sciences, Faculty of Agricultural and Food Sciences and Environmental Management, Institute of Crop Sciences Böszörményi u. 138 H-4032 Debrecen Hungary
Five inbreds (UDL1, UDL4, UDL5, UDL6, 126) from our preliminary maize improvement program for increased starch content and some of their hybrids were grown in 2008 at the field of Horticultural Institute, Debrecen University. Three chemical parameters (starch-, protein-, oil content) and the weighing of one physical trait (thousand-kernel weight) were analyzed. The starch content varied from 64.29–70.80% in lines and from 70.84–72.29% in case of hybrids. Protein content in the dry material was between 9.04–12.62% in case of the parent lines and it was 7.61–9.56% in the single cross hybrids. Strong negative correlation (r = −0.834**) was found between starch and protein content of the examined hybrids. The oil content varied from 2.70–3.64% and 2.87–3.39% in lines and hybrids, respectively. The thousand-kernel weight (TKW) varied between 213.6–341.3 g in case of the lines and it was 314.3-426.3 g in hybrids. Significant differences were found among hybrids in TKW (SD5% = 34.66%). Heterosis was experienced in the starch content of UDH6 hybrid. Both the relative and absolute values of heterosis for starch content and kernel weight were positive for each single cross hybrid.