Somatic hybridization of nitrate reductase deficient mutants of nicotiana tabacum by protoplast fusion
Glimelius, K.; Eriksson, T.; Grafe, R.; Muller, A.J.
Physiologia Plantarum 44(3): 273-277
1978
ISSN/ISBN: 0031-9317 DOI: 10.1111/j.1399-3054.1978.tb08631.x
Accession: 006437518
Protoplasts were isolated from 2 mutant cell lines of N. tabacum L. cv. Gatersleben and fused with the aid of polyethylene glycol. Both mutants lacked nitrate reductase and were thus auxotrophic for reduced N. The fusion resulted in a high frequency of hybrid cells which were detected by their regained ability to grow in media containing nitrate as sole N source. Thus, the 2 mutants complement each other in the hybrids. In control experiments, back mutation and cross-feeding were excluded as possible explanations for the occurrence of cell lines utilizing nitrate. A total of 1061 hybrid lines capable of sustained proliferation were isolated. Some were further characterized with respect to nitrate reductase activity, chlorate sensitivity, chromosome number and shoot formation. Apparently protoplast fusion can be used for the genetic analysis of cell variants of higher plants and nitrate reductase-deficient mutants provide efficient selective systems for hybrid cells.
