Benzyladenine can alleviate saline injury of two roselle (Hibiscus sabdariffa) cultivars via equilibration of cytosolutes including anthocyanins

The changes in dry matter and the concentration of organic solutes in roots, shoots and sepals of two roselle (Hibiscus sabdariffa L.) cultivars (cvs. light red sepals & deep red sepals) under salt stress and spraying with 250 mg L-1 benzyladenine (BA) were assessed. The cv. light red sepals tolerated salinity up to 25 mM NaCl, while cv. deep red sepals showed least tolerance to salinity stress. This was accompanied with differences in accumulation of saccharides, nitrogen compounds and anthocyanins. The reaction to salt stress was expressed as proline accumulation in both roots and shoots of two roselle cultivars with higher response in deep red sepals. Anthocyanins content was also higher in cv. light red sepals (more salt tolerant) than cv. deep red sepals (more salt sensitive). These results suggest that differences in anthocyanins content in the two-roselle cultivars under NaCl are a kind of response to this abiotic environmental stress. The results of the same experiment indicated that the application of BA could partially alleviate the salt stress symptoms in both roselle cultivars.