Effects of various preculture, pretreatment, and recovery conditions on the morphogenetic response of cryopreserved Lady Orange chrysanthemum shoot tips

Abstract

The aim of this research was to optimize the encapsulation-dehydration cryopreservation protocol of Lady Orangechrysanthemum explants on the preculture, pretreatment, and post-rewarming recovery steps. Shoot tips were precultured on MSmedium with various abscisic acid concentrations (0–30 µM). Next, the encapsulated explants were osmotically dehydrated for 3 or5 days and desiccated for 3–4 h and, after rewarming, they were subcultured on recovery media of various compositions (control andcytokinin/auxin-supplemented). A high explant survival rate, even up to 100%, was observed. The value of this parameter, however,changed depending on the post-rewarming culture duration. Moreover, not all the viable explants were capable of forming shoots. Alower ABA concentration (15 µM) during preculture and the presence of 4.65 µM kinetin in the post-rewarming recovery mediumenhanced cryopreservation efficiency with a high survival rate and typical microshoot formation. A higher ABA concentration andthe presence of 6-benzylaminopurine in the recovery medium resulted in shoot multiplication, abundant callus formation, and rootformation inhibition.