Estimation of the Heterotic Effect in F1 Generation of Various Tobacco Genotypes and Their Diallel Crosses

ABSTRACT

Two-years trial (2007 - 2008) was set up in the field of Tobacco Institute-Prilep, to study the mode of inheritance and heterotic effect for the characters: height of the stalk with inflorescence, height of the stalk without inflorescence, leaf number, middle belt leaf area, green mass yield and dry mass yield per stalk. The investigations included four parental genotypes (the oriental pink flowered Suhum S1, white flowered Suhum S2 and red flowered Prilep-84, and the large-leaf variety Burley B-2/93 in CMS form) and their six diallel F1 hybrids. The trial was set up in randomized blocks with four replications and traditional cultural practices were applied in tobacco growing.

The analysis of variance revealed statistically justified differences between parents and their progenies for the characters investigated. Positive heterosis with poor heterotic effect was recorded in S1 × S2 hybrid for stalk height with and without inflorescence and for green/dry mass yields in S2 × P-84, while in S2 × P-84 only for height of the stalk without inflorescence. Negative heterosis with poor heterotic effect was recorded in hybrids S1 × P-84 for leaf number and for green/dry mass yields and S2 × P-84 for leaf number and green mass per stalk. The low heterotic effect indicates that application of heterosis is economically unjustified, but in the same time it points out to the eventual breeding activities for creation of new and more superior varieties.

Keywords:

• tobacco
• Nicotiana tabacum L
• diallel cross
• inheritance
• heterosis
• heterotic effect