Effects of carbohydrate, light, nitrogen and magnesium on In Vitro production of anthocyanin in apple

Abstract

Anthocyanins as a secondary metabolite in plants, have a great nutritional value in human diet and a vast application in food industry. In-vitro culture of plant cells can be an alternative method for commercial production of large amounts of several important secondary metabolites. Some crab apples mostly native to Central Asia and Siberia, can produce anthocyanin in their various organs including fruit flesh. The aim of this study was to determine the best source and optimum concentration of carbohydrates, including sucrose, glucose, fructose, maltose and mannitol, magnesium, light intensity and nitrogen source to produce anthocyanin from in vitro callus culture of a red-fleshed crab apple. The results showed that the mannitol concentration of 3% plus 3% sucrose was the most effective carbohydrate treatment for anthocyanin production. Increasing mannitol concentration resulted in reduced anthocyanin content, callus growth index and fresh weight; while, callus dry weight increased. The highest anthocyanin content and the lowest callus growth index were observed in 6% sucrose among used concentrations. Glucose, fructose and maltose had weaker effects on anthocyanin content. Enhancing light intensity led to a significant upsurge in the amount of anthocyanins. Changing the nitrogen source also influenced anthocyanin content and the best combination of nitrogen source for producing anthocyanin was the 10 mM ammonium plus 18.8 mM nitrate or concentration of 5 mM ammonium plus 25 mM nitrate. Through adding magnesium to the medium boosted anthocyanin content up to 3 times and the most abundant anthocyanin was obtained at the highest concentration of magnesium.