Plantes Haploides et Lignes Isogeniques deNicotiana TabacumObtenues par Cultures D'Antheres et de Tiges in Vitro

Abstract
SUMMARYThe in vitro production of tobacco haploid plants by anther culture (NITSCH'S medium) was applied to various tobacco cultivars of great agronomic interest.The origin of the embryoids appears to be mostly due to the division of the vegetative nucleus of the male gametophyte but one albina plantet was obtained indicating that the generative nucleus can occasionally give a haploid plant.The cytophotometric measurements of the DNA content of the pith nuclei in the haploid plants, compared with the chromosome numbers of the plants regenerated from haploid stem calluses, shows that haploid cells are generally responsible for plant regeneration (ca. 50 to 60%), but also diploid and, in exceptional cases, tetraploid cells can regenerate a plant.The in vitro culture of stem disk coming from haploid plant thus offers the possibility of i) multiplying the haploids and ii) obtaining, at same time, plants isogenic at the diploid and tetraploid levels.