The effect of auxin and signaling compounds on growth and production of secondary metabolites in vitro cultures of Whortleberry (Vaccinium arctostaphylos L.)

 Whortleberry is one of the important medicinal plants in traditional medicine that has been used in Iran for decades in reducing blood sugar and blood pressure adjustment. In the present study, the effect of auxin, gibberellin (GA3), casein hydrolysate (CA), putrescine (PU), and salicylic acid (SA) on in vitro establishment and growth of Whortleberry explants and the amount of anthocyanin, flavonoid and total phenolic compounds in in vitro condition were evaluated. The apical bud and nodal explants were collected from natural habitat, surface sterilized and cultured on the MS medium supplemented with 2 mg/L BAP and different concentrations of NAA or IBA (0.01- 1 mg/l) and MS medium supplemented with 2 mg/L BAP and 0.1 mg/L NAA or IBA and different concentrations of gibberellin (0- 0.5 mg/l), CA (0- 150 mg/l), PU and SA (0- 10 mg/l). The results indicated that the percentage of explant viability and leaf producing explants were significantly influenced by auxin type and concentration. So, the percentage of explant viability and explants leaf production on MS media supplemented with low concentration of NAA were significantly higher than those of the higher concentration of NAA and all levels of IBA. Addition of GA3 to the culture medium was significantly increased the number of leaves per explant. Furthermore, CA, PU and SA led to an increase in the percentage of explants leaf production and number of leaves per explant, but this increase was not statistically significant in some of these treatments. Moreover, the amount of secondary metabolites was significantly affected by medium compositions. So, the highest amount of anthocyanin was observed in the MS + 2mg/l BAP+0.1mg/l IBA and the highest amount of flavonoids and total phenolic compounds were observed in the same medium 15 mg