The effect of plant growth regulators on the in vitro regeneration capacity in some horticultural crops and rare endangered plant species

The screening of PGRs for their influence on in vitro regeneration pathways of some valuable cultivars Fragaria × ananassa, Lavandula × intermedia, Chrysanthemum × morifolium, Ficus carica, and rare endangered species, Aconitum lasiostomum and Crithmum maritimum was carried out. Twenty-one variants of the MS medium were tested. For the chrysanthemum shoot tip development, the MS culture medium with 0.5, 0.75 mg L^‑1 kinetin, and 0.05 mg L^‑1 NAA were optimal. The use of 0.73-1.46 mg L^‑1 metatopoline (mT) promoted better regeneration of explants in chrysanthemum, strawberry, common fig, lavandin, and A. lasiostomum. It was found out that using 3.0, 9.0 µM mT, 6.0, 9.0 µM TDZ, or 1.5 mg L^‑1 BAP + 1.5 mg L^‑1 IBA induced direct regeneration in A. lasiostomum. Active development of adventitious buds and root formation on the shoot slices were observed. 0.5, 1.0 mg L^‑1 BAP + 0.05 mg L^‑1 NAA, or 1.5 mg L^‑1 BAP + 1.5 mg L^‑1 IBA in the culture media stimulated the regeneration up to 4-5 microshoots explant^‑1 in lavandin. At 3.0 and 6.0 μM mT, a high morphogenetic response in C. maritimum explants was noted with initiation of development up to 12 buds explant^‑1 and spontaneous rhizogenesis. The optimal concentrations of PGRs in the MS culture medium for successful in vitro regeneration of the studied genotypes were determined.