Theoretical and Applied Genetics

, Volume 115, Issue 2, pp 169–178

The negative influence of N-mediated TMV resistance on yield in tobacco: linkage drag versus pleiotropy

  • R. S. Lewis
  • L. R. Linger
  • M. F. Wolff
  • E. A. Wernsman
Original Paper

DOI: 10.1007/s00122-007-0552-y

Cite this article as:
Lewis, R.S., Linger, L.R., Wolff, M.F. et al. Theor Appl Genet (2007) 115: 169. doi:10.1007/s00122-007-0552-y
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Abstract

Resistance to tobacco mosaic virus (TMV) is controlled by the single dominant gene N in Nicotiana glutinosa L. This gene has been transferred to cultivated tobacco (N. tabacum L.) by interspecific hybridization and backcrossing, but has historically been associated with reduced yields and/or quality in flue-cured tobacco breeding materials. Past researchers have suggested the role of pleiotropy and/or linkage drag effects in this unfavorable relationship. Introduction of the cloned N gene into a TMV-susceptible tobacco genotype (cultivar ‘K326’) via plant transformation permitted investigation of the relative importance of these possibilities. On average, yield and cash return ($ ha−1) of 14 transgenic NN lines of K326 were significantly higher relative to an isoline of K326 carrying N introduced via interspecific hybridization and backcrossing. The negative effects of tissue culture-induced genetic variation confounded comparisons with the TMV-susceptible cultivar, K326, however. Backcrossing the original transgenic lines to non-tissue cultured K326 removed many of these unfavorable effects, and significantly improved their performance for yield and cash return. Comparisons of the 14 corresponding transgenic NN backcross-derived lines with K326 indicated that linkage drag is the main factor contributing to reduced yields in TMV-resistant flue-cured tobacco germplasm. On average, these transgenic lines outyielded the conventionally-developed TMV-resistant K326 isoline by 427 kg ha−1 (P < 0.05) and generated $1,365 ha−1 more (P < 0.05). Although transgenic tobacco cultivars are currently not commercially acceptable, breeding strategies designed to reduce the amount of N. glutinosa chromatin linked to N may increase the likelihood of developing high-yielding TMV-resistant flue-cured tobacco cultivars.

Abbreviations

TMV

Tobacco mosaic virus

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • R. S. Lewis
    • 1
  • L. R. Linger
    • 2
  • M. F. Wolff
    • 3
  • E. A. Wernsman
    • 1
  1. 1.Crop Science DepartmentNorth Carolina State UniversityRaleighUSA
  2. 2.AlamedaUSA
  3. 3.CaryUSA

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