Endogenous levels of plant growth substances in seeds of five bamboo species in relation to seed viability

Endogenous levels of auxins and ABA in seeds is found to be one of the major factors related to the loss in seed viability in stored bamboo seeds. This was examined during storage for one year, under controlled conditions, in 5 bamboo species by means of various viability tests. Endogenous levels of putative free indole acetic acid (IAA) and free and bound abscissic acid (ABA) were measured in freshly harvested seeds and in seeds stored for one year. In freshly harvested seeds, free IAA levels were higher in all species in comparison to one-year-old seeds. Seeds of Thyrsostachys siamensis showed highest viability (G% 76.6) and maximum content of IAA (2.90 μg g⁻¹ fw) while the seeds of Dendrocalamus strictus showed lowest viability (G% 5.53) and lowest content of IAA (2.07 μg g⁻¹ fw). Same pattern of IAA was observed in seeds stored for one year but the IAA levels were found to be reduced and so did the viability across all species. The free and bound ABA levels in freshly harvested seeds were maximum in D. strictus, with lowest viability. After one year, the amount of free ABA increased by about 58% while the bound ABA was found to be reduced by 78% in this species.