Accepted 22nd June, 2020.
Growth and ripening rates are important traits in flue-cured tobacco (Nicotiana tabacum L.) farming as they determine the field management required and indirectly influence the yield and quality of the cured leaf obtained from a variety. In this study growth rate was measured as the number of days from planting to 50% topping and while ripening rate was measured as the number of days from onset of reaping to 50% reaping. Understanding the nature of genes controlling growth and ripening rate in flue-cured tobacco is important as it allows breeders to predict with relatively high precision the outcome of breeding programmes. The F1 offspring of a 10 × 10 full Griffings’ Diallel Method IV cross were evaluated in an alpha – lattice design experiment containing 100 entries in two replicates over a period of two years during the 2015/16and the 2016/17 summer seasons at Kutsaga Research Station under rain-fed conditions. Hayman analysis in the Statistical Package for the Sciences (SAS) 2014 Version was employed on the growth and ripening rate data which showed that the two traits exhibited partial dominance. The results indicate that it is possible to select for growth and ripening rate in flue cured tobacco breeding programmes.
Keywords: Nicotiana tabacum L.; growth rate; ripening rate; partial dominance; alpha lattice design; Hayman analysis