Differentiation of maize inbred lines in order to assess their degree of relationship and their classification into germplasm groups or in heterotic groups is performed using different methods. For the primary differentiation the method of pedigree is used, which gives us information on the origin of the initial material of selection. Knowledge of the relationship between diversity and the maize inbreds has a significant impact on establishing maize breeding programs in creating hybrids for framing inbred lines germplasm in groups and for creating original biological material. The paper aim is to determine the degree of relatedness/ differentiation of the lines created from two synthetics (Tu SRR Comp. A and Tu SRR Comp. B). The two synthetic composites were created starting from the late maturity inbred lines B 73 (Tu SRR Comp.A) and Mo 17 and C 103 (Tu SRR Comp. B). B 73 inbred line is part of the Stiff Stalk Synthetic germplasm, while Mo 17 and C 103 belong in the Lancaster Sure Crop group. For Tu SRR Comp A there were used as parental genotypes A632, CM 105, TB 329 and T 291 inbred lines, while for the second synthetic composit, besides the two inbred lines from the Lancaster Sure Crop, there were also used T 248, W633 and TC 208. The biological material used consisted of eight inbred lines and 28 hybrids. Four inbred lines were obtained from Tu SRR Comp. A and four from Tu SRR Comp. B. between these inbred lines, there were performed (4) p(p-1)/2 diallel crossing, resulting in 28 hybrids. The study was conducted in the two experimental years: 2013 and 2014, at the Agricultural Research and Development Station Turda. The experimental model used was randomized block with four repeats. There were analyzed an important number of traits: for inbred lines: plant height, ear height, leaf area, total number of leaves/plant, number of leaves above the ear, number of tassel ramifications, tassel length and tassel main axis, while for hybrids there were taken into consideration the plant height, ear height, leaf area and the total number of laves/plant. In order to determine the factors involved in the expression of the traits we used the analysis of variance and the orthogonal variance decomposition into its components, inbred lines pedigree. There were performed biometric measurements of the phenotypic characters and general combining ability was calculated.

composite, germplasm, inbred

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