Bull. Spec. CORESTA Congress, Guangzhou 1988, p. 123, PP-5
N. tabacum aneuploid plants from protoplasts
Istituto Sperimentale per il Tabacco, Scafati, Italy
In vitro culture techniques offer tools for genetic improvement of cultured plant species. Among these, somatic hybridization from protoplast fusion is widely used. In our research, freshly prepared protoplasts were incubated with a 50% PEG 6000 solution for ten minutes at room temperature, diluted with the culture medium (a final concentration of 20.000/ml), and cultured in the dark for 5 days at 24.degree.C. Protoplasts were then slowly diluted to 10.000/ml with fresh l ml of culture medium added each day for the next 5 days. After 2-3 months developed calli were transferred on solid MS medium lowered in macro and micro nutrients and cultured for a year with several transferring in the same medium, and the last one in a normal MS medium plus BAP 0,4 mg/ml. Regenerate plantlets that showed changes in chloroplast number of stomatic cells were isolated, and grown up till flowering. By the Feulgen technique on the root apex we observed that aneuploid plants with a chromosome number ranging from 36 to 86 were fertile, while a greater chromosome number gave sterile plants. It is argued that by anther culture and subsequent chromosome doubling other unfamiliar Nicotiana species could be obtained from these aneuploid plants.