Glycoalkaloid aglycone accumulations associated with infection by Clavibacter michiganensis ssp. sepedonicus in potato species Solanum acaule and Solanum tuberosum and their interspecific somatic hybrids

• Published in: Plant cell reports 2005-03, Vol.23 (10-11), p.683-691
• Main Authors: Rokka, V.M, Laurila, J, Tauriainen, A, Laakso, I, Larkka, J, Metzler, M, Pietila, L
• Format: Article
• Language: English
• Subjects: Actinomycetales - physiology; aglycone; anther culture; backcrossing; bacterial ring rot; Biological and medical sciences; Biotechnology; Clavibacter michiganensis; Clavibacter michiganensis subsp. sepedonicus; Eukaryotic cell cultures; Fundamental and applied biological sciences. Psychology; Genetics; glycoalkaloids; hexaploidy; Hybridization, Genetic; Hybrids; interspecific hybridization; Methods. Procedures. Technologies; Miscellaneous; Plant cells and fungal cells; Plant Diseases - microbiology; plant pathogenic bacteria; plant regeneration; Potatoes; protoplast fusion; Regeneration; Solanaceous Alkaloids - metabolism; Solanum; Solanum - metabolism; Solanum - microbiology; Solanum - physiology; Solanum acaule; Solanum tuberosum; Solanum tuberosum - metabolism; Solanum tuberosum - microbiology; Solanum tuberosum - physiology; somatic hybridization; tetraploidy; Tissue Culture Techniques; Vegetables
• ISSN: 0721-7714; 1432-203X
• DOI: 10.1007/s00299-004-0868-x

Solanum acaule Bitt., a wild potato species, is closely related to cultivated potato (Solanum. tuberosum L.). Incorporation of desirable traits from allotetraploid [2n=4x=48, 2 endosperm balance number (EBN)] S. acaule (acl) into autotetraploid (2n=4x=48, 4EBN) S. tuberosum (tbr) is difficult due to incongruity boundaries. In this study, three hybrid combinations, each with a specific genome constitution, were produced through protoplast fusion: (1) hexaploid 2x acl (+) 4x tbr, (2) tetraploid 2x acl (+) 2x tbr, and (3) hexaploid 4x acl (+) 2x tbr hybrids. In terms of glycoalkaloid aglycones, the hybrids produced demissidine, tomatidine and solanidine, similarly to the S. acaule parental species, but S. tuberosum synthesised only solanidine. Inoculations with Clavibacter michiganensis ssp. sepedonicus (Cms), which is the causal agent of bacterial ring rot in potato, yielded significantly lower total glycoalkaloid aglycone accumulation both in S. acaule plants and in interspecific hybrids in comparison with the corresponding mock-inoculated plants. However, in S. tuberosum the aglycone levels were either higher or unchanged as a result of infection by Cms. To incorporate the desirable traits of the interspecific somatic hybrids into 4EBN S. tuberosum, sexual backcrosses were carried out. The hexaploid 4x acl (+) 2x tbr hybrids with the hypothetical 4EBN showed the greatest capacity to undergo backcrosses with S. tuberosum.