Direct and Maternal Genetic Variances and Covariances of Seedling Characters in Tobacco1
- D. A. Van Sanford and
- D. F. Matzinger2
A diallel crossing scheme was used to estimate genetic parameters for seedling weight, root length, and day of germination in a random mating tobacco (Nicotiana tabacum L.) synthetic population. Estimates were obtained from plants grown under two nutrient levels in aseptic culture in controlled environmental growth chambers. Significant estimates of direct additive and dominance variances and, maternal additive variance for seedling weight were obtained in both stress and optimal nutrient levels. The heritability for seedling weight in the optimal environment, 0.178, was larger than that in the stress environment, 0.124. Predictions of selection response were greater for performance on either the stress or optimal nutrient level if selection would be conducted in the optimal environment. Correlations among characters varied between the two nutrient levels. The large correlations between seedling fresh weight and root length for direct additive and maternal additive effects were of opposite sign, leading to prediction of little change in root length when selecting for increased seedling weight.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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