Field Response of Tobacco after Ten Generations of Selection for Seedling Weight
1989
Matzinger, D. F. | Wernsman, E. A.
Indirect selection may be a viable technique in certain situations for improving correlated traits. This study was designed to evaluate the efficacy of seedling selection as a means of improving mature plant performance. Field evaluations were conducted on nine generations of a Black Shank Resistant Synthetic tobacco (Nicotiana tabacum L.) population that had been selected 10 generations for 19-d seedling weight on regular or stress nutrient agar. Linear increases in mean yield cycle⁻¹ were 1.43 g plant⁻¹ for the population selected on stress nutrient agar and 0.99 g plant⁻¹ when selection was on regular nutrient agar. The only other significant change detected was a decrease in total alkaloids of 0.65 mg g⁻¹ cycle⁻¹ for the regular nutrient agar selections. The lack of a decrease in total alkaloids accompanying the increase in yield of the stress agar selections suggests indirect selection of root modifications that increased the efficiency of total alkaloid synthesis. The increase in yield from 10 cycles of indirect seedling recurrent mass selection on stress agar was equivalent to about 1.5 cycles of direct recurrent mass selection for yield in other field experiments. Paper no. 12005 of the Journal Series of the North Carolina Agric. Res. Serv., Raleigh, NC 27695-7643.
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