ISHS Acta Horticulturae 447: III International Symposium on In Vitro Culture and Horticultural Breeding
INTRASPECIFIC SOMATIC HYBRIDIZATION IN DIHAPLOID POTATO |
| Authors: | K. Sonntag, R. Thieme, H. Tiemann |
| Keywords: | Solanum tuberosum, protoplasts, electric fusion, hybrid identification, flow cytometry |
| Abstract:
Intraspecific somatic hybridization by using electrofusion was performed with 12 clones of dihaploid potatoes (2n=2x=24) to combine genomes and to transfer interesting agronomic traits for quality and resistance and to supplement and complement conventional breeding methods. The techniques used for the isolation of protoplasts from leaf mesophyll tissue of plantlets have been described previously. Dielectrophoresis was induced by an AC field of 18 – 20 Vcm-1 and fusion was effected by two DC pulses each of 15 μs duration. Different shoot culture media were required. Four percent of protoplast-derived calli regenerated shoots, depending on the cultivar genotype and the genotype combination. Flow cytometric measurements of the ploidy level showed that more than 60 % of the regenerants were tetraploid, 7 % were diploid and 33 % were hexa-, octo- or mixoploid. 464 somatic hybrids, i.e. 39 % of the analyzed plants were identified by isozyme and RAPD analysis. For further investigations the hybrid plants were transferred to the greenhouse and to the field. Evaluation of intraspecific somatic hybrids revealed new variability among the hybrids. Their yield is dependent on the parental genotype and the ploidy level. The best results were obtained in genotypes with tetraploid level. | |
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