Genetic Effects of Some Phenotypic Characteristics in Tobacco

The lifespan of tobacco seeds ranges from 5-7 years, and then they begin to deteriorate genetically as a result of hybridization and the occurrence of mutations naturally. Therefore, an genetic improvement process for this crop must be carried out continuously.

The experiment was carried out during the years 2023-2024 in kassab village, Lattakia, Syria, by cultivating three tobacco genotypes (Basma, Prilep, and Gob-Hasan). A half-diallel cross was made between different genotypes of tobacco.

In the following season, an evaluation of the genotypes was performed, which were distributed according to the randomized complete block design (R.C.B.D) with three replicates to estimate the nature of gene action for: plant height, leaves number, internodes length, plant leaf area and leaf area index.

The results show high differ significantly for all traits, which refer to differ among the parents. The genetic analysis shows important both additive and dominant effects to heredity in all studied characteristics. The additive gene action dominated the inheritance of: plant height, internodes length, plant leaf area and leaf area index. But the non-additive gene action dominated the inheritance of leaves number.

The prilep parent exhibited a high means for: leaves number (22 leaf/plant), plant leaf area (192 cm2). However, The Gob-Hasan parent exhibited a high means for: plant height (75.60 cm), internodes length (3.5 cm), leaf area index (1.26).

The hybrid Basma × Gob-Hasan exhibited the highest means for: plant height (72.70 cm), internodes length (3.46 cm). The hybrid Prilep × Gob-Hasan exhibited the highest means for: leaves number (24.6 leaf/plant), plant leaf area (136.20 cm2), leaf area index (1.3). We conclude that the hybridization method can be adopted to obtain new tobacco varieties with high leaf yield.