Heterosis and combining ability analysis in some Turkish tobacco varieties

Abstract

Six Turkish tobacco cultivars and their 15 F1 hybrids, excluding reciprocals, were evaluated to obtain estimates of combining ability and heterosis for five agronomic and four chemical traits. With the exception of ash content, average heterosis was significant for all characters studied. The average yield of hybrids was 15.2 % above that of the parents. Higly significant general combining ability (GCA) variances were observed for all traits evaluated. On the other hand, variances of specific combining ability (SCA) were significant for chemical attributes. Additive gene action appeared to play a greater role in the inheritance of all characters, except total nitrogen. The line 40-18B was identified as being the most combiner overall parent in the experiment for improving the characters investigated. Based on signifiant SCA effects, together with significant heterosis. the crosses 3×4. 3×6. and 2×3 would be suitable combinations.