In vitro micropropagation of Dianthus plumarius subsp. praecox, a wild carnation species, for ornamental horticultural and gene conservation purposes

•A protocol for micropropagation of Dianthus plumarius ssp. praecox was developed.•Consecutive application of ZEA and BA resulted in high yield of in vitro shoots.•Replacement of ZEA with BA resulted in in vitro shoots with high rooting ability.•The hyperhydration of the shoots was recovered by using PGR-free medium.•The survival percentage of plantlets was high during the acclimatization. Carnation is important floral crop. The introduction of wild carnation species is carried out in parallel with research on existing species and varieties. Dianthus plumarius subsp. praecox is a wild species with an extremely high germplasm conservation importance. The most important step in the study of its cultivation is to propagate it in vitro under conditions of minimum impact on nature. Therefore, present work aimed to develop an in vitro micropropagation protocol for this species. Different types of cytokinins, such as 6-benzylaminopurine, 6-benzylaminopurine riboside, meta-topolin, N-(2-chloro-4-pyridyl)-N’-phenylurea, kinetin, N6-(2-isopentenyl) adenine, zeatin and adenine sulfate, was applied for the in vitro multiplication. Cytokinins were applied alone in a concentration of 4.5 µM, or in the combination of 2.25 µM BA and 2.25 µM KIN. Their effect on the in vitro shoot multiplication and their after-effects on the in vitro rooting were tested. Based on the present detailed study, a micropropoagation protocol was developed, where high shoot multiplication rate (4.7 ± 0.4 shoot/explant with 25.1 ± 1.4-mm-long shoots) could be achieved using zeatin as cytokinin source in the shoot multiplication medium. For successful in vitro rooting 6-benzylaminopurine-containing medium was applied for 3 weeks after shoots multiplication phase on zeatin-containing medium, then shoots were conditioned for 2 weeks on plant growth regulator free medium directly before rooting. With this treatment hyperhydration of in vitro shoots could be decreased from 91 % to 12 % and high frequency (86.7 %) in vitro rooting was gained. Rooted in vitro shoots were successfully acclimatized in 71 %.