Molecular diversity and phenotypic responses of two in vitro Solanum tuberosum varieties by physical mutagen

ABSTRACT

Induction of mutation in potato (Solanum tuberosum L.) plants by gamma radiation is considered an effective method for plant improvement. Solanum tuberosum L. is a vegetative plant, its tuber is starch-rich and it has worldwide economic importance. Two potato buds varieties (Valor and Spunta) were cultured in vitro on MS medium supplemented with 0.2 mg/l 6-Benzylaminopurine (BAP). The resulting plantlets were irradiated with gamma radiation doses of 10, 20, 30 and 40 Gy. Irradiated single node pieces were transferred onto fresh MS medium supplemented with BAP. Plantlet survival percentage and the other phenotypic criteria were calculated after eight weeks. Gamma radiation caused a moderate decrease in the survival percentage and the phenotypic criteria. Microtubers produced from irradiated plantlets changed in size compared to the control. The estimated proline content in irradiated plantlets was increased with increasing gamma radiation dose. The genomic DNA of the two varieties generated 150 bands. The maximum number of bands was 13, while the minimum number of bands was 5. Fifty-four polymorphic bands were amplified and the percentage of polymorphism ranged from 12.50 to 66.66% for two varieties. The highest genetic identity was 0.9672, between irradiated plantlets of the Valor variety with doses of 20 and 30 Gy. However, the highest genetic distance was 0.3995 observed between irradiated plantlets with a dose of 20 Gy in the Valor variety and 30 Gy in the Spunta variety. The dendrogram generated by cluster analysis distinguished the irradiated plantlets genetically. All of the mutants Spunta obtained via gamma irradiation were genetically very distant from the control.

KEYWORDS:

• Solanum tuberosum
• in vitro culture
• gamma radiation
• phenotypic criteria
• RAPD
• DNA polymorphism

Disclosure statement

No potential conflict of interest was reported by the authors.