DNA Amplification among Anther‐Derived Doubled Haploid Lines of Tobacco and Its Relationship to Agronomic Performance

Abstract

Anther culture in tobacco (Nicotiana tabacum L.) has been associated with yield losses and DNA amplification without chromosome number changes among doubled haploid lines. The objectives of this study were to confirm the amplification phenomenon and to determine if increases in DNA are correlated with yield losses. Total nuclear DNA was determined for two cultivars, ‘NC95’ and ‘Coker 139’ (C139), and six doubled haploid (DH) lines derived from cultivar. The DHs were selected so that approximately equal increments of yield losses would be present among the array. The DNA analysis was performed via flow cytometry on isolated nuclei stained with the DNA‐specific fiuorochrome propidium iodide. Agronomic data also were collected on the DH lines. Results indicated that genotypic effects for nuclear DNA were highly significant. While the DNA increases observed among the NC95 genotypes were not statistically significant, doubled haploids derived from C139 had significantly more DNA per nucleus than C139. Coker 139 DHs also sustained greater yield reductions from the parental cultivar than did the NC95 DH lines. Regression analyses of meanuclear DNA values of C139 genotypes on mean leaf yields resulted in a correlation coefficient of ‐0.69; this was significant only at the 0.1 probability level. While DNA amplification among anther‐derived doubled haploids of tobacco was confirmed in one cultivar, DNA amplification and yield losses do not appear to be strongly correlated. The lack of a linear relationship between these two variables may be caused by different chromosomal amplification sites among the doubled haploid lines.