Effect ofin vitro storage at 4°C on survival and proliferation of two apple rootstocks

Abstract

One cm long shoot explants of dwarf apple rootstocks P 2 and M.9 taken from 2 year-old cultures were stored at 4°C in the dark in three media differing in concentration of growth regulators. Every 6 weeks, some explants were transferred into proliferation medium and multiplication rate was observed during three or four consecutive passages. In a second experiment, the influence of explant type (1 cm long shoot tips, 1 cm long middle part of shoots or three-shoot tufts smaller than 1 cm) and transfer time to the cold room (immediately, 10 days, or 20 days after subculture) on explant survival and proliferation were analysed.Survival of explants was influenced by composition of the storage media. On medium without 6-benzylaminopurine, 70% of P 2 and 17% of M.9 explants became necrotic during 18 weeks of storage. P 2 rootstock proliferated better in three passages after storage than did unstored controls. Storage of M.9 rootstock reduced proliferation in the first and second passages if stored in media containing 6-benzylaminopurine in comparison with unstored controls. Explants stored as tufts and transferred to the cold room directly after subculture produced more shoots during two passages than cultures stored as single shoots.

In vitro slow growth storage of Senecio macrophyllus shoots

“…The best results have been observed when storage was performed in darkness for Malus (Orlikowska 1992), Pistacia (Koç et al 2014), Populus (Hausman et al 1994), and Quercus (Romano and Martins-Loução 1999). Similar results were reported for S. macrophyllus where light affected negatively culture viability, multiplication rate and rooting response.…”

“…The most important factor in the slow growth culture is temperature reduction, often with a simultaneous decrease in light intensity or even culture in the dark, which limits shoot growth from callus induction and proliferation of the base of the shoots. According to the data this minimizes further growth and the development of plantlets or other explants is already guaranteed by the use of a temperature of 0-10°C (Orlikowska 1992;Hausman et al 1994;Reed 2002). Furthermore, by modifying the composition of the medium mainly by reducing the sucrose content and/or minerals, the use of hormonal growth retardants, e.g.…”

In vitro storage of plum germplasm by slow growth

“…Among periods of storage, the multiple comparisons were performed using the Tukey's HSD or Scheffe's test while mean differences between samples were tested by the Student's t-test; n.s. -no significant differences; (-) -no regeneration or died during storage Several authors ascribed necrosis and browning during cold storage to the presence of light and found them to be less pronounced in darkness (Hausman et al 1994;Romano, Martins-Loução 1999) or when BAP was lacking in the storage medium (Orlikowska 1992). Furthermore, Bairu et al (2009) supposed that when plants are cultured in a cytokinin-free medium, cytokinins are depleted from the shoots; the absence of roots decreases the endogenous cytokinin level, stopping cell division and causing apical necrosis.…”

“…To our knowledge, little information exists on preserving P. domestica and especially P. cerasifera by slow growth, although some species and clones belonging to Prunus have been investigated by this technique (Marino et al 1985;Sauer 1985;Janeiro et al 1995;Pérez-Tornero et al 1999;Lambardi et al 2006). To slow down the growth, we preserved the genotypes at 4°C in the dark, as successfully tested in Prunus and in several other species (Marino et al 1985;Sauer 1985;Orlikowska 1992;Hausman et al 1994;Negri et al 2000;Lambardi et al 2006) testing two concentrations of sucrose and the presence/absence of plant growth regulators in the storage medium.…”

Efficient long-term conservation of Taraxacum pieninicum synthetic seeds in slow growth conditions

“…Similarly, Mallus sp. rootstocks (Orlikowska 1992), Prunus armeniac shoot tips (Pérez-Tornero et al 1999), rootstocks of different species of Prunus (Marino et al 1985) were best preserved in the dark. Necrosis and browning observed during cold storage under light conditions were less pronounced in darkness in Populus tremula × Populus tremuloides shoots (Hausman et al 1994) and Quercus suber shoots (Romano and MartinsLoução 1999).…”