comparison of burley tobacco doubled-haploid lines with their source inbred cultivars

A doubled-haploid line was randomly derived from each of seven burley tobacco, Nicotiana tabacum L., cultivars using anther culture and leaf-midvein chromosomal doubling. The doubled-haploid lines were compared to their source inbred cultivars in two experiments for several agronomic and chemical characters. A consistent relationship between anther-derived materials and reduced vigor was not observed in these doubled-haploid lines. Significant differences between the doubled-haploid mean and their source cultivar mean were observed only for days to flower and total alkaloids. The doubled-haploid means were not significantly different from their source cultivar means for yield, plant height, and leaf number. In total, 26 of the 35 individual comparisons between a doubled-haploid line and its source cultivar were nonsignificant. Reciprocal crosses between the doubled-haploid lines and their source inbred cultivars also demonstrated no significant differences. The diallel progeny of the seven doubled-haploid lines showed a similar genetic performance to that of diallel progeny from conventional materials in previous studies. The differences observed between the doubled-haploid lines and their source inbred cultivars could be explained by residual heterozygosity. The performances of the doubled-haploid progeny could also be attributed to the presence of residual heterozygosity in the original cultivars. As tested by reciprocal crosses, cytoplasmic effects were not significantly involved in the performance of the double-dhaploid lines.