A robust in-vitro protocol for shoot multiplication of Echinacea angustifolia

Abstract

Echinacea angustifolia is an important medicinal and ornamental plant found in various regions of the world. This species may become threatened due to over-exploitation for medicinal uses. The present study was carried out to develop a rapid in vitro multiplication protocol using explants raised from seedlings. Complete plantlets have been successfully regenerated from shoot tip, leaf, petiole, stem, and root explants. The explants were incubated on Murashige and Skoog (MS) culture medium supplemented with different combinations of 6-benzyl amino purine (BAP) naphthalene acetic acid (NAA). Multiplication of shoot tips was achieved on BAP while from other explants; multiple shoots were regenerated on MS medium supplemented with BAP and NAA. The response of growth regulators was investigated. The shoot tip explants showed the highest rate of shoot induction (80%) and a shoot regenerated about 25 shoots per explants when cultured on MS media supplemented with BAP (4 µM) within 6–7 weeks. The leaf explants also developed shoots and each shoot generated 15 shoots in MS medium supplemented with BAP (5 µM) and NAA (5 µM). Shoot regeneration was also achieved with other explants mainly root, petiole, and stem on MS medium containing BAP (5 µM) + NAA (5 µM). The multiple elongated shoots were obtained on MS basal medium. Well-developed roots were achieved on MS medium in combination with BAP and NAA and 80% of plantlets were survived in the soil successfully in the hardening process. A robust and optimized protocol will be helpful for the mass production of this medicinal plant.