Long-term cold storage of clonal apple rootstocks on growth media with added jasmonic acid: effect and their subsequent development <I>in vitro</I>

Abstract

The article examines the effect of jasmonic a cid used at concentrations of 0.1-1.0 mg/L in the longterm continuous in vitro cold storage of clonal apple rootstock explants (54-118, 57-490, 57-545, and MM 106) on their subsequent development on under standard cultivation conditions. A positive effect of jasmonic acid was noted on the preservation of the viable explants of clonal apple rootstocks at all used concentrations over a period of 48-54 months (+3-6 ℃) of continuous cold storage, as compared to the explants cultivated without its application. Different concentrations of jasmonic acid in the cold storage medium were found to have no significant effect on the net reproduction of explants that were subsequently cultivated without jasmonic acid under standard cultivation conditions (+20-22 ℃). However, a significant increase in the length of microshoots (by 1.4-1.6 times) and the average number of leaves per microshoot (by 1.2-1.6 times) was observed in all studied forms of clonal apple rootstocks on growth medium with a jasmonic acid concentration of 1.0 mg/L. Subsequently, these explants exhibited no delay in vegetative development in vitro as compared to the explants that did not undergo cold storage (control). Jasmonic acid addition to the growth medium for long-term continuous cold storage at can be recommended as a way to improve the preservation of explants when clonal apple rootstock collections are stored for long periods of time in in vitro culture.