Epistatic gene effects on the yield of the parents of F-1, F-2, BC1 and BC2 progeny

The genetic analysis of 5 tomato hybrids (Danubius F-1, Luna F-1, Lido F-1, Balkan F-1 and Mi-10 F-1) was made. We produced their F-1. F-2, BC1 and BC2 generations and analysed their yield (on the first three flower branches) as well as some of the yield components of tomato fruits (mean fruit weight, mean fruit weight on the first flower branch, fruit length, fruit width, and number of locules). In order to estimate the gene effects, we applied the additive-dominance mode with three and six parameters. Epistatic gene effects were estimated by applying the six-parameter mode (Mather and Jinks 1982). As for yield and yield components, there were significant differences between the mean values of parents and their progeny. On the basis of the investigated genetic parameters, the obtained results suggested that the additive and dominance gene effects prevailed in the yield and yield components (Danubius F-1, Luna F-1, Lido F-1, Mi-10 F-1), whereas epistatic gene effects were excluded. As for the hybrid Balkan Fl, we recorded significant gene effects, both the additive and the dominance ones in the yield inheritance: additive x additive and dominance x dominance (with the negative sign). The estimated values of the epistatic gene effects were the most prominent in inheriting the feature average fruit weight on the first flower branch - additive x dominance gene effects. They represented the most frequent type of the interallele interaction recorded in the investigated hybrids