Ali Izzo(1)*, Hassan Khojah (1), Abdel Mouhsen Marie(2)
(2) Department of Horticulture, Faculty of Agriculture, Tishreen University, Latakia, Syria.
(2) General commission for scientific Agricultural Research (GCSAR), Syria.
(*Corresponding author: Ali Izzo; E-Mail: izzo198899@gmail. Com).
Received:29/08/2021 Accepted: 19/10/2021
Abstract:
The study was conducted in Al-Jamasah station, Tartous agricultural research center, Syria, during 2019 and 2020 seasons. Randomized Complete Blocks Design (RCBD) with three replications was used. Generation mean analysis method was used to study the type of gene action using some genetic indices of the six population of two individual hybrids of tomato (T2×T8) and (T8×T16). Single plant yield, number of days to first flowering, number of fruits per cluster, fruit weight, fruit length, fruit diameter, number of locules per fruit were studied. Average and close phenotypic and genotypic coefficients of variation values were detected for most of the studied traits. This indicates a high contribution of the genetic component in trait expression. Heterosis compared to the better parent in the first filial (F1) was accompanied by genetic Inbreeding depression in the second filial (F2). Most of the traits had average estimates of the degree of heritability in their narrow sense, which indicates that the additive and non-additive gene actions controlled their inheritance. The analysis of the average generations showed that the additive and dominance gene actions were significant for most of the studied traits, with superiority of the dominance gene action values. Epistasis gene action from the additive × additive and dominance × dominance types contributed in the inheritance of most of the studies traits. The contrast between the two signs of the dominance and the epistasis gene actions from the type (dominance × dominance) in most of the traits indicated that it was from the duplicate type in majority of the studied traits and consequently selection could be conducted in later filials. while gene action was from the Complementary type for number of days to flowering in the second hybrid and number of locules per fruit in the first hybrid, so those traits could be improved by taking advantage of heterosis.
Key words: Tomato, yield, gene action, heritability, Genetic advance, Potence ratio.
Full paper in Arabic: pdf