Investigations were made on the mode of inheritance of green and dry mass yields per stalk and genetic analysis was of six parental tobacco genotypes (P-23, MB-3, SM-1, YV 125/3, FL-5 and O-87), with fifteen diallel crosses of each generation: F1, F2, BC1(P1) and BC1(P2). The trial was set up in 2008-2009 on the Experimental field of Scientific Tobacco Institute - Prilep in randomized block system with four replications, using standard agrotechnical practices during the vegetation period. The aim of investigations was to study the genetics of inheritance of green and dry mass, using genetic components of variance to determine the types of genes as carriers of the characters and to assess the impact of the environment on their manifestation. The yield is the most important agronomic character inherited mostly by partial dominance. Positive heterosis was observed in the hybrid MB-3 x YV 125/3 and negative heterosis in FL-5 x O-87. Genetic analysis of the four investigated generations revealed that additive genes were dominant in creation of yield. Results presented in this paper will give good directions in tobacco selection.

Key words:Tobacco (Nicotiana tabacum L.), mode of inheritance, heterosis, genetic analysis,components of genetic variance