engleski

Quantitative parameters of some Burley tobacco traits

The purpose of this study was to determine manner of inheritance, heritability, heterosis effect and inbreeding depression in Burley tobacco for days to flowering, height after topping, number of leaves, yield and grade index. Four parental cultivars (TN 86, BL1, Hy 71, Poseydon) and their F1, F2, Bc1 and Bc2 progenies were studied in a four-year experiment carried out in the region of Zagreb. The experiment was organized as a RCBD with four replications. Twenty five plants per experimental plot were used for analyses of the morfhological and agronomic traits. Larger nonadditive, than additive, variance was found for all the studied traits. For most traits in most years an overdominance was found. Rather high values of h2b were determined for almost all the traits whereas h2n was very low. Positive heterosis effect in F1, in comparison to the the better parent, was found for topping height, number of leaves and yield, and negative for days to flowering and grade index. The highest trait values were obtained with the Hy 71 x BL1, Poseydon x BL1 and Poseydon x TN 86. F1 hybrids. Also in F2, inbreeding depression was found for all the traits for which the positive heterosis effect in F1 was found. Distribution of parental genotypes along the expected regression line showed genetic divergence of the parental cultivars for most studied traits. The highest number of dominant genes were found for the TN 86 cultivar and of recessive genes for the BL1 and Hy 71 cultivars.

Burley tobacco; heritability; heterosis; inbreeding depression; regression analysis

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