In vitro shoot multiplication of Haplophyllum virgatum and flavonoid elicitation in proliferated shoots by methyl jasmonate

Haplophyllum virgatum var. virgatum is an Iranian endemic plant. Its only natural habitat is the Geno region in the Hormozgan province of Iran. This plant’s limited distribution and special habitat conditions prompted us to investigate the possibility of its micropropagation and different biological aspects. In this study, while evaluating seed germination and seedling production of H. virgatum in two Murashige and Skoog (MS) and Gamborg (B5) culture media, shoot multiplication and rooting of single-node shoot explants of this plant were also investigated in the MS culture medium containing different concentrations of growth regulators. Flavonoids are part of the medicinal metabolites of different Haplophyllum species. Here, the flavonoid elicitation in the proliferated shoots of H. virgatum under 0, 100, and 150 µM methyl jasmonate (MeJA) treatments was done. The results demonstrated that the MS culture medium was more suitable than B5 for seed germination and natural growth of seedlings. Moreover, for H. virgatum shoot multiplication, one mg/L kinetin was more appropriate compared to other concentrations of this cytokinin (0.5, 1.5, 2, 2.5, and 3 mg/L) and the corresponding concentrations of benzyl amino purine. Rooting was achieved only in a limited number of shoots, so it needs further investigation. Meanwhile, MeJA increased total phenolic, total flavonoid, and rutin (the main flavonoid of Rutaceae) contents in the proliferated shoots. This research provided new information about the micropropagation of H. virgatum and flavonoid elicitation by MeJA in this plant.