Endogenous levels of reducing sugars, free amino acids and phenols during various stages of in vitro culture of cotton (<i>Gossypium Spp.</i>)

Abstract

Somatic embryogenesis is widely preferred as the regeneration route for in vitro studies in cotton. However, the regeneration efficiency through this approach is low; a problem that is believed to be as a result of the biochemical properties of the plant. The objective of this study was to investigate possible relationships between three biochemical factors (reducing sugars, phenols, and free amino acids) and somatic embryogenesis. In vitro cultures of the different embryogenic and non-embryogenic cultivals were established. The levels of reducing sugars, phenols and free amino acids were determined at different developmental stages of the cultures. Higher levels of reducing sugars and lower level of phenol were observed in embryogenic cultivars compared to their non-embryogenic counterparts. There was a general increase in the levels of free amino acids, which decreased with time in the highly embryogenic cultivars, whereas the levels remained high in the poorly embryogenic and non-embryogenic cultivars. The higher content of phenols and free amino acids may be implicated in the poor somatic embryogenic response. The data show that there are factors that may serve as markers of somatic embryogenesis in cotton, which need to be empirically determined for any particular cultivar chosen for genetic improvement through embryogenesis.