Micropropagation and ex vitro acclimatization of Lonicera caerulea var. altaica: molecular identification and protocol optimization

Abstract

Abstract L. caerulea var . altaica occurs within diverse ecosystems of the Altai region and is highly valued for its frost tolerance and beneficial bioactive compounds. This study developed an efficient protocol for micropropagation and ex vitro acclimatization of valuable honeysuckle species. Species identification was performed using a dual DNA barcode approach with the combined rbcL and matK markers. Phylogenetic analysis revealed that specimen ABG_LA_kz grouped with the epitype, verifying its taxonomic identity. Shoot multiplication was conducted on QL medium supplemented with 0.5 mg·L⁻¹ 6-BAP, 0.2 mg·L⁻¹ GA₃, and 0.01 mg·L⁻¹ IBA. After 35 days, this treatment yielded an average of 6.53 shoots per explant, with shoot height of 2.96 cm and 37 leaves per explant. For in vitro rooting, ½ QL medium comprising 1.5 mg l − 1 IBA proved to be most effective, with an average 4.52 roots formed per explant and rooting percentage of 83.3% within the same culture period. An ex vitro acclimatization protocol using a peat: perlite (3:1) resulted in an average of 12.16 roots per plantlet, with an 100% survival. Thirty five days after acclimatization, 303 seedlings were transplanted to the nurseries of the RSE on REM “Altai Botanical Garden” and RSE on REM “Mangyshlak Experimental Botanical Garden”.