Improving micropropagation efficiency and biochemical content of pineapple (Ananas Comosus) using stevia extract

Shoot tips of pineapple (Ananas comosus) cultivar "Queen" were cultured individually on MS medium supplemented with 2.0 mg/L BA+0.1 mg/L NAA+0.4 mg/Lthiamine HCL for establishment stage. Clusters were re-cultured to study the effect of stevia extract on in vitro proliferation, rooting and biochemical content of pineapple plantlets. Sucrose at different concentration (10, 20 and 30g/L) and stevia extract at 7, 13 and 20 ml/L were tested during multiplication and rooting stage of in vitro growing pineapple plants. Moreover, different biochemical analysis such as total carbohydrates, total sugars, starch, phenols, flavonoids as well as chlorophyll A, B and AB were estimated. The obtained results assured that sucrose at 30 g/L is the optimum dose of carbon for shoot multiplication of pineapple. Meanwhile, during rooting stage, the highest roots number and roots length were obtained when MS medium was supplemented with 20 g/L sucrose combined with 7 ml/L stevia. This combination also increased total sugars, starch and chlorophyll B content of pineapple leaves. However, sucrose alone showed superiority in some chemical content under study (total carbohydrates, flavonoids and chlorophyll A).From this investigation, we can conclude that sucrose is an important source of carbon for in vitro multiplication of pineapple plants while, stevia extract is more efficient for plantlets growth in rooting stage.