Pedigree and Breeding MethodsDelgold was developed in an inter-specifichybridization study. A colchicine-derivedtetraploid (4n) Nicotiana tabacum L. 'Vir-ginia 1 l5' was crossed in 197 | to a deploid(2n) female parent from N. rustica L. 'Ba-bor'. The resultant interspecific hybrid didnot produce seed on selfing indicating ste-rility. However, repeated pollination of thehighly sterile F, inter-specific hybrid withdiploid (2n) Virginia 115 produced a fewbackcross-one (BC,) seed in 1972. TheseBC, progenies were grown in a breedingnursery in 1913 for their agronomic, mor-phological and chemical characterization.Most of the BC, progenies were off-typesCan. J. Pfant Sci. 64t 233-236 (Jan. 1984)233with a bushy habit of growth and high de-gree of sterility. An individual BC' selec-tant, with high leaf total alkaloids, wasbackcrossed to N. tqbacwn 'Hicks Broad-leaf' as a diploid female parent in thegreenhouse. A selected high leaf total al-kaloid genotype from the second backcross(BCr) generation was further backcrossedas the female parent with a diploid Virginia115. Normal floral fertility and flue-curedtobacco phenotype were restored amongthe segregants of the BC, generation. Sub-sequent to the BC. generation, individualplant selection and selfing were carriedout, and by 1976 a fully fertile diploidstrain 76N2 was evaluated in an early gen-eration testing program. A set of sevenwell-differentiated sister-1ines, based onleaf dimension and shape, plant type andcolor, was established from the 76N2 bulkpopulation. Performance evaluations con-ducted under the designation 76N2-E iden-tified the strain to be superior to its othersister-lines and the check cultivar Virginia115. Certified seed production began in1 980.