In vitro selection of NaHCO3 tolerant cultivars of Morus alba (Local and Sujanpuri) in response to morphological and biochemical parameters

In vitro experiments were conducted to study the effect of NaHCO3 (alkalinity) stress on saplings of Morus alba (cv. Local and Sujanpuri) cultured from nodal explants. For shoot multiplication 2.5 mg/l of 6-benzylaminopurine (BAP) with 0.3 mg/l gibberellic acid (GA(3)) were used and root formation was induced with 1.0 mg/l of indolebutyric acid (IBA). NaHCO3 salt was added to the culture medium in three concentrations, i.e. 3.57, 20.0 and 59.0mM that increased pH to 6.2, 7.2 and 8.2, respectively. The increased salt concentration affected survival and growth parameters, subsequent cultures promoted them. The cultured biomass was analyzed for proline, protein, sugars and chlorophyll content. The results indicate an increase of proline, protein and sugars; however, they declined at higher concentrations of NaHCO3. A decrease of chlorophyll was observed at all stress regimes.