With 1 figure and 4 tables
Abstract
Fertile sesquidiploid BC1 of interspecific hybrids between N. tabacum cv. ‘Wiślica’ and N. glauca were previously produced to transfer N. glauca‐type resistance into tobacco. Tobacco breeding lines (‘WGL’) BC2F5–BC2F7 carrying black root rot resistance were obtained after one generation of backcrossing to cv. ‘Wiślica’ followed by five to seven generations of selfpollination. A 3‐year study was conducted to compare the agronomic value of ‘WGL’ lines with that of the parental cultivar ‘Wiślica’. Plant height and number of leaves per plant in all ‘WGL’ lines were similar to that of ‘Wiślica’. There were some significant variations for leaf characteristics. The most distinct effect was extended duration of the vegetative stage. All the ‘WGL’ lines showed delayed flowering compared to ‘Wiślica’. The ‘WGL’ lines were inferior to the parental cultivar with regard to weight of 10 dm2 of leaf blade. There were no major differences for nitrogen, sugars and nicotine contents. These results indicate that incorporation of the N. glauca‐type resistance into tobacco genome did not produce negative effects on morphological and chemical traits.