Minimal growth conservation of potato microplants: silver thiosulfate reduces ethylene-induced growth abnormalities during prolonged storage in vitro

Abstract

 Efficacy of silver thiosulfate (STS) in reducing ethylene-induced culture abnormalities during minimal growth conservation of microplants was studied in seven potato (Solanum tuberosum L.) genotypes. Different concentrations of STS (0, 1.5, 3.0, 4.5, 6.0, 7.5 and 9.0 μg ml^–1) were tested in minimal growth medium based on MS medium supplemented with 20 g l^–1 mannitol and 40 g l^–1 sucrose. STS improved the microplant growth and reduced the culture abnormalities during prolonged maintenance of potato shoot cultures in vitro. The beneficial effect of STS was most prominent for number of green leaves per microplant and leaf senescence. After 16 months of storage, desirable microplant growth was observed in cultures conserved in medium containing 6.0–9.0 μg ml^–1 STS. The profile of the peroxidase isozymes of conserved cultures did not show any apparent genetic variation due to the presence of STS in the conservation medium.