Combining ability analysis in tobacco (Nicotiana tabacum L.)

Five tobacco varities viz., 2–1 Gujrat Tobacco 5 (GT 5), Gujrat Tobacco 7 (GT 7), Anand 145 and Anand 119 thier twenty hybrids (including reciprocals) were evaluated in randomised block design with two replications. The mean squares for gca were significant for all the caracters under study barring spangle score and leaf thickness, while sca mean squares were significant in case of plant height, leaf length and leaf breadth. Reciprocal mean squares were non significant for all characters. The ratio of gca to sca variances was greater then unity suggesting preponderance of additive gene action for all the characters under study. General combining ability effects suggested that variety 2–1 and Anand 145 for early flowering, and 2–1 for leaf curl incidence, GT 5 and GT 7 for yield, plant height, number of leaves, leaf length and leaf breadth were good general combiners. Cross GT 5 x A 145 for number of leaves per plant, GT 5 x A 119 for leaf length and breadth showed significant desired sca effects.