The paper aims to appreciate the degree of relationship / differentiation of lines created from a single source of original material. Relatively limited research has been done with related inbred lines (Musteață and Mistreţ, 2002), which at the present stage predominates in the maize improvement programs. Differentiating the sister lines, made from a single source of source material and related lines from various sources with common genitors, allows for their identity to be identified, a necessary element in the selection and hybridization process. Differentiating the sister lines, made from a single source of original material and related lines originating from various sources with common genitors, allows the determination of their identity, a necessary element in the selection and hybridization process. Determination of the degree of similarity was done by various methods:the pedigreeof the lines, morphological characters, heterosis (production and production elements) and general combining ability. There were studied 7 inbred lines of common origin, among which crosses of type (4) p (p-1) / 2 dialel were made. Both parental lines and crosses were studied at SCDA Turda, within the maize amelioration laboratory in the year 2016. At the parental lines, 22 phenotypic characters were studied after the UPOV system. From the heterosis calculation made from the crossing of the 7 lines (of common origin), heterosis values> 90% result for: grain production, ear weight, grain weight, insertion height and foliar surface. The purpose of this paper is to assess the degree of similarity of the lines created from a single source of the original material, which has allowed the establishment of their identity, a necessary element in the selection and hybridization process.

similarity, heterosis, inbred lines

field crops and pastures

Presentation: oral