TRANSFER OF CYTOPLASMIC MALE-STERILITY BY SPONTANEOUS ANDROGENESIS INTOBACCO (NICOTIANA-TABACUM-L)

Five cytoplasmic male sterile lines of Nicotiana tabacum homozygous fo r a dominant rootless mutation [Rac-] were used as female parents in c rosses with three male fertile varieties. Androgenetic haploids were s elected by their ability to form plantlets with a normal root system, whereas hybrid plantlets failed to grow. High frequencies of androgene tic haploid plants were obtained with N. debneyi cytoplasm, and with o ne paternal genotype. Chromosome doubling was performed using three di fferent methods (pollination, in vitro culture, acenaphthen) and cytop lasmic male sterile doubled haploid plants have been obtained. The res ults demonstrate the efficiency of this method for a rapid cytoplasm t ransfer in Nicotiana tabacum; the integrity of the cytoplasm is conser ved. For the first time, we possess a counter selectable marker univer sally usable for Nicotiana tabacum and closely related species.