Effect of a Second Cycle of Anther Culture on Flue‐Cured Lines of Tobacco1

Abstract

Doubled haploid (DH, 2n = 48) lines were produced via anther culture from two long‐term inbred flue‐cured tobacco (Nicotiana tabacum L.) cultivars. Anther culture was then performed on the first cycle DH lines, generating arrays of second cycle DH lines. Chromosome doubling was accomplished either with colchicine treatments or via leaf midvein culture. Source cultivars and first and second cycle doubled haploids (DHS) were tested in agronomic performance trials in 1980 and 1981. Each cycle of anther culture resulted in a reduction in vigor approximately equal in magnitude when compared to selfed progenies of their respective anther source. Cured leaf yields were reduced an average of 17% per cycle of androgenesis. Anther culture was also associated with the creation of significant genetic variability among lines arising from a single homozygous source, regardless of cycle number. These results cannot be explained in classical genetic terms by the existence of residual heterozygosity in the original source cultivar. Results of the second cycle of anther culture and chromosome doubling of the haploid confirm the capacity of the system to induce genetic changes in flue‐cured tobacco.