In vitro propagation, genetic stability, and secondary metabolite analysis of wild lavender (Lavandula coronopifolia Poir.)

Lavenders (Lavandula species) are important aromatic ornamental medicinal plants with wide ranging applications in perfume and pharmaceutical industries. We developed an in vitro propagation protocol for Lavandula coronopifolia. Murashige and Skoog (MS) medium supplemented with 0.5 mg·L-1 N 6 -benzyladenine was the best medium for the proliferation of microshoots, while the highest rooting frequency was obtained using MS medium supplemented with 1.0 mg·L-1 indole-3-butyric acid. Inter-simple sequence repeat analysis revealed that the in vitro-propagated microshoots were highly genetically stable, even after subculture. The highest callus fresh weight (667.9 mg) was obtained by propagating on medium supplemented with a combination of 1.0 mg·L-1 naphthaleneacetic acid and 0.5 mg·L-1 butyric acid. Using the Folin-Ciocalteu method, methanolic extracts of wild L. coronopifolia revealed total phenolic content of 4.9 mg expressed in gallic acid equivalents (GAE) (mg GAE·g-1 dry matter). Radical scavenging activity was estimated at 85% using the free radical 2,2-diphyenyl-picrylhydrazyl assay. Using the brine shrimp assay for cytotoxicity, the methanolic extract was found to be nontoxic. Finally, liquid chromatography tandem mass spectrometry with standard reference compounds was used to quantify the key phenolic compounds in both in vitro and in vivo-grown L. coronopifolia. Six major phenolic compounds were identified: caffeic acid, rosmarinic acid, rutin, quercetin, luteolin, and hesperidin. Levels of these phenolic compounds were highest in wild plant extracts.