Micropropagation of lavender: a protocol for production of plantlets

Abstract

Lavender (Lavandula dentata) has several medicinal applications, both in the fresh form and after industrial processing. Productivity increase could be obtained through the mass propagation, expanding the possibility of obtaining raw material for production of essential oil. The objective of this work was to develop a micropropagation protocol from explants obtained from seeds. Aspects of in vitro germination, multiplication, elongation and rooting were evaluated and, in sequence, the acclimatization process as well. The in vitro germination of lavender seeds can be obtained using a medium composed of agar and water. For multiplication, the use of MS medium (Murashige & Skoog, 1962) added with 5.0 µM 6-benzylaminopurine to the nutrient medium is the most appropriate. For elongation and rooting, the use of growth regulators is unnecessary. Acclimatization can be obtained directly by transferring the explant to plastic bags with substrate, kept in a greenhouse. It was possible to develop a protocol for the in vitro cultivation (establishment, multiplication, elongation, rooting and acclimatization) of lavender from explants of seed origin.

Multiplication of lavender (L. angustifolia) and lavandin (Lavandula x intermedia) in explant culture

“…In our experiments, the formation of calluses on the base of shoot segments was observed, especially in varieties of L. x intermedia -the larger ones (up to 20 mm in diameter) on var. Budrovka, but they did not interfere with the shoot development, as was also reported in other papers (Mitrofanova et al 2020;Koefender et al 2021) li et al (2019) described the most effective shoot induction and multiplication from nodal segments of L. angustifolia (without variety specification) on the medium with 1 mg/L BaP combined with 0.3 mg/L IBa. Kara and Baydar (2012) compared the regeneration of shoot tips and stem nodes in the varieties of L. angustifolia var.…”

“…During regeneration, shoot vitrification occurred in all media and varieties, although the incidence of vitrification was half as low in the variety Budrovka. this problem has also been described in other species of lavender, like L. dentata (Koefender et al 2021) or L. pedunculata (Zuzarte et al 2010). Since vitrification is an irreversible physiological malformation, its occurrence is undesirable because it reduces the efficiency of multiplication.…”

“…However, some works concerning indirect propagation via callus have also been published (Dronne et al 1999;Leelavathi et al 2020;al-tai & Mohamed 2022). Shoot cultures of lavender are usually established from seeds (Kirimer et al 2017;vinh et al 2017;Miclea & Chifor 2018;Koefender et al 2021) or stem cuttings (Hamza et al 2017;Li et al 2019) from which apical buds or nodal segments are excised. However, only the establishment of culture from cuttings can be considered a strictly vegetative propagation method.…”

“…therefore, the micropropagation protocol needs to be optimized not only for each species but also for each variety. Usually, cytokinin BaP (6-Benzylaminopurine) (Kirimer et al 2017;vinh et al 2017;Li et al 2019;Koefender et al 2021), alternatively kinetin, thidiazuron or zeatin (Hamza et al 2011;Miclea & Chifor 2018) without or with auxins Naa (1-Naphthaleneacetic acid), Iaa (Indole-3-acetic acid) or IBa (Indole-3-butyric acid) have been used for shoot induction from initial explants and their multiplication. Plant regulators-free medium (Miclea & Chifor 2018;Koefender et al 2021) or media supplemented with auxins Iaa (vinh et al 2017), Naa (Li et al 2019) or IBa (Hamza et al 2011;Kirimer et al 2017) have been recommended for rooting of shoots.…”

“…Usually, cytokinin BaP (6-Benzylaminopurine) (Kirimer et al 2017;vinh et al 2017;Li et al 2019;Koefender et al 2021), alternatively kinetin, thidiazuron or zeatin (Hamza et al 2011;Miclea & Chifor 2018) without or with auxins Naa (1-Naphthaleneacetic acid), Iaa (Indole-3-acetic acid) or IBa (Indole-3-butyric acid) have been used for shoot induction from initial explants and their multiplication. Plant regulators-free medium (Miclea & Chifor 2018;Koefender et al 2021) or media supplemented with auxins Iaa (vinh et al 2017), Naa (Li et al 2019) or IBa (Hamza et al 2011;Kirimer et al 2017) have been recommended for rooting of shoots. Micropropagation of other lavender species (L. latifolia, L. vera, L. pedunculata, L. viridis, L. spica, L. dentata) have also been described (summarized in Gonçalves and Romano 2013), but there are only several papers concerning micropropagation of L. x intermedia by direct or indirect organogenesis (Kara & Baydar 2012;erland & Mahmoud 2014;Mitrofanova et al 2020).…”