Mycorrhizal fungi and growth and development of micropropagated Scutellaria integrifolia plants

Scutellaria species have been used in many traditional medical systems and is well known among the Native American tribes as a strong emmenagogue and as a female medicinal herb. The inoculation of arbuscular mycorrhiza fungi (AMF) into the roots of micropropagated plantlets could help not only mass propagate these species, but also help grow in marginal, phosphorus deficient soils. Leaves, shoot apices, and nodal segments from wild as well as from greenhouse-grown plants were used to initiate cultures in Murashige and Skoog (MS) medium supplemented with cytokinins benzyladenine (BA), kinetin, thidiazuron (TDZ), naphthalene acetic acid (NAA), and indole butyric acid (IBA) Among all the explants tested for shoot bud induction, only shoot tips and nodal explants were responsive. Explants swelled and became rough on the surface at the end of 3-week incubation with many green shoot buds. Two to 3 weeks after transfering to rooting media with or without IBA, all shoots developed roots. In vitro raised plants were acclimatized in a mist chamber and transferred to 6-l containers in the greenhouse to study the role of AMF on plant growth and development. Inoculation with AMF, showed positive effects on plant growth, particularly root development compared with the control plants. Among the five AMF strains tested, S3004 increased plant height and fresh weights of shoot, root, and seed.