Transfer of cytoplasmic male sterility by spontaneous androgenesis in tobacco (Nicotiana tabacum L.)

Five cytoplasmic male sterile lines of Nicotiana tabacum homozygous for a dominant rootless mutation of (Rac super(-)) were used as female parents in crosses with three male fertile varieties. Androgenetic haploids were selected by their ability to form plantlets with a normal root system, whereas hybrid plantlets failed to grow. High frequencies of androgenetic haploid plants were obtained with N. debneyi) cytoplasm, and with one paternal genotype. Chromosome doubling was performed using three different methods (pollination, in vitro culture, acenaphthen) and cytoplasmic male sterile doubled haploid plants have been obtained. The results demonstrate the efficiency of this method for a rapid cytoplasm transfer in Nicotiana tabacum ; the integrity of the cytoplasm is conserved. For the first time, we possess a counter selectable marker universally usable for Nicotiana tabacum and closely related species.