Identification of QTLs Associated with Some Morphological Traits in Oriental Tobacco

In order to identify quantitaive trait loci (QTLs) associated with morphological traits including number of leaves, leaf length, leaf width, leaf area, leaf fresh weight, leaf dry weight, plant height and stem diameter in oriental type tobacco, a genetic population comprising 100 F2 individuals from a cross between two oriental type genotypes, namely Basma seres 31 (maternal) x SPT 406 (paternal) was evaluated under field conditions. Subsequently a linkage map based on 23 simple sequence repeat (SSR) markers and 29 inter simple sequence repeat (ISSR) markers was constructed which covered 570.8 cM of tobacco genome. Composite interval mapping could identify 11 QTLs involved in controlling the investigated traits. The maximum percentage of phenotypic variance (R2) explained by QTLs was 25.2%. In this study, no QTL was identified for number of leaves. The results showed the existence of co-localized QTLs for some of the studied traits including plant height, leaf length, stem diameter and leaf dry weight which enhances the efficiency of marker-assisted selection in tobacco breeding programs.