Cold storage of in vitro apple germplasm in Kazakhstan

B. Kabylbekova, I. Kovalchuk, N. Chukanova, T. Turdiyev
The duration of in vitro cold storage (at 3 and 4°С, 7-15 μmol m‑2 s‑1 light intensity and 10 h photoperiod) in plastic breathable packages of three apple cultivars ‘Voskhod’, ‘Golden Delicious’, and ‘Maksat’ were studied. The effect of three sources of carbohydrates (3% sucrose, 2% or 3% mannitol, or 2% sucrose + 2% mannitol) in MS culture medium with 0.5 mg L‑1 BAP and 0.1 mg L‑1 IBA or without plant growth regulators (PGRs), the effect of abscisic acid (AA) in three concentrations (0.1, 0.5, and 1.0 mg L‑1) and three concentrations of nitrogen (NO3) (100, 50, and 25%) were determined. Apple shoots remained viable for 18-20 months without repeated multiplication under conditions of cold storage on a standard (control) MS medium with 3% sucrose (1962) with and without PGRs. The effect of the cultivar and medium composition on the duration of cold storage was determined. The increase in storage time was with a decrease in the nitrogen concentration in the MS medium to 25 or 50%. In these cases, the storage time was extended to 30 months without PGRs and up to 28 months with PGRs compared to controls. The shoots depending on the cultivar remained viable (rating ≥2) from 24 to 25 months on MS medium and a combination of carbohydrates of 2% sucrose + 2% mannitol regardless of the hormonal background. The addition of abscisic acid regardless of the concentration in the medium with 3% sucrose increased storage also up to 24-30 months. The effect of the cultivar was insignificant. The longest storage time was recorded for ‘Golden Delicious’ (30 months), the shortest storage time for ‘Maksat’ (24 months). In vitro germplasm bank contains 27 apple cultivars on an optimal MS medium with 50% NO3 and 2% sucrose + 2% mannitol without PGRs.
Kabylbekova, B., Kovalchuk, I., Chukanova, N. and Turdiyev, T. (2021). Cold storage of in vitro apple germplasm in Kazakhstan. Acta Hortic. 1324, 77-82
DOI: 10.17660/ActaHortic.2021.1324.11
apple cultivars, growth regulators, carbohydrates, germplasm bank

Acta Horticulturae