In vitro flowering in Bambusa bambos (L.) Voss, an anatomical perspective

Bamboo [Bambusa bambos (L.) Voss (Syn. Bambusa arundinacea Retz.)] is an important arborescent grass with immense socio economic implications. The plant exhibits unique biological and growth characteristics including a distinct monocarpic gregarious flowering behavior. Studies on in vitro flowering in bamboo are not uncommon. The present study focuses on effect of different growth regulators on in vitro flowering in B. bambos and analyzes the morphological and developmental changes accompanying the process. Multiple shoots were raised from B. bambos seeds on MS medium supplemented with 10 μM BAP. Anatomical sections showed intense mitotic activity in the apical meristem of the main shoot and formation of additional shoot buds along the margins. For multiplication, propagules of 7-9 shoots were transferred to maintenance medium containing 5 μM BAP. Longitudinal sections of propagules showed prolific cell divisions and formation of meristemoids, which continuously gave rise to new shoots upon subculture. In vitro induction of flowering in cultures was observed in multiple shoots after 8 weeks. Transfer of multiple shoots to MS basal medium containing 10 μM NAA resulted in rooting and proliferation of inflorescences. On medium supplemented with 10 μM 2,4-D callusing and development of shoot buds and somatic embryos was followed by development of inflorescences. The report outlines a protocol that can be used to raise and proliferate flowering cultures in B. bambos.