Induction of somatic embryogenesis and organogenesis in Oldenlandia umbellata L., a dye-yielding medicinal plant

Abstract

Oldenlandia umbellata L., commonly known
as ‘‘Indian madder’’, is an ancient Indian herb valued as a
source of red color dye and various medicinal products. In
this study, successful protocols have been developed for
induction of somatic embryogenesis and organogenesis in
O. umbellata. Emerging young leaves, shoot apices, and
stems were used as explants, grown on Murashige and
Skoog (MS) media supplemented with various auxins,
including indole acetic acid, indole butyric acid, napthaleneacetic
acid (NAA), and 2,4-Dichlorophenoxyacetic
acid, each at levels ranging between 0.1 and 0.5 mg/l,
cytokinins, including benzyladenine (BA) and kinetin, each
at concentration ranging between 0.5 and 5 mg/l, with and
without coconut milk (CM) at levels of 0.5–5%. For callus
induction, NAA at 2.5 mg/l was optimal; while, for rapid
embryogenic callus induction, 0.2 mg/l NAA, 0.5 mg/l
BA, and 0.1% CM induced the highest frequency
(95.86%). Shoots developed upon transfer of embryogenic
calli to MS medium containing 1.5 mg/l BA, 0.3 mg/l
NAA and 1% CM. For root induction, 0.3 mg/l NAA and
1.0% CM promoted highest and earliest rooting.