Comparative Study of Drought Tolerance of Virginia Tobacco Genotypes Differing in Origin and Their Corresponding Hybrid Progenies

Abstract

Soil drought is a serious problem in agriculture leading to considerable loss of production. Tobacco is relatively sensitive to water scarcity, and the selection of resistant drought varieties is of particular importance. In this study we compared the tolerance to three different levels of drought of six genotypes of Virginia tobacco – two varieties were introduced in Bulgaria, two lines are of Bulgarian origin, and two are their hybrids. Biochemical markers of stress (malondialdehyde, hydrogen peroxide and free proline) were determined. The results showed that the Polish genotype V 385 and one of the Bulgarian lines L 0842 were moderately sensitive to drought, while the parental genotypes – the American variety Coker 254 and the Bulgarian line L 0543, as well as the two newly created Bulgarian hybrids H 27 and H 135 were relatively resistant to drought. These data can serve as a basis for selection and development of new genotypes with increased resistance to drought.