Micropropagation of Vitex agnus-castus©

N.K.A. Nor Hisham Shah, M. Bridgen
Vitex agnus-castus or the chaste tree is a large shrub that is important as a medicinal and an ornamental plant. It is well known for its medicinal properties in hormone regulations (Snow, 1996); research is actively being conducted to prove the medicinal properties of the shrub (Van Die et al., 2013). In addition to being an important herbal medicine, the shrub also possesses ornamental properties with promising marketable value (Dirr, 2015). The shrub has fragrant palmately compound leaves and produces spikes of lavender flowers in the late summer that attract pollinators (Gilman and Watson, 1994). It can grow in many types of soil with good drainage and the shrub does not attract deer. Lastly, Vitex is not known to be affected by any major pest or diseases.
Vitex has a few weaknesses (Dirr, 2015); the shrub has an aggressive growth habit and can grow up to 20 ft in length and width. This quality likely deters home owners and landscape architects to use Vitex in a landscape. Another weakness of Vitex agnus-castus is that it has limited flower colors. Currently the flower colors that are available commercially are limited to two: purple-blue and pink. Lastly the shrub is not cold tolerant or hardy in zones colder than zone 7 (USDA Plant Database). This limits the landscape or area that the plant can be used.
Considering the economic potential of Vitex, a breeding program will be able to improve Vitex as an ornamental plant. An important step to this goal is to outline the micropropagation protocols for this plant.
Nor Hisham Shah, N.K.A. and Bridgen, M. (2017). Micropropagation of Vitex agnus-castus©. Acta Hortic. 1174, 275-284
DOI: 10.17660/ActaHortic.2017.1174.56

Acta Horticulturae