Effect of cytokinin type and concentration, and source of explant on shoot multiplication of pineapple plant (Ananas comosus ‘Queen’) in vitro

The current study was conducted to test cytokinin type and concentration, and source of explant on shoot multiplication of pineapple plant (Ananas comosus ‘Queen’) in vitro during 22/6/2009 to 1/5/2010. The results of the first experiment showed that axillary buds delayed to grow during 4-5 months of culturing in MS medium supplemented with different concentrations of BA (1.0, 1.5, 2.0, 2.5 or 3.0 mg l-1). The MS medium supplemented with 1.0 mg l-1 BA has led to the vegetative growth of axillary buds. The other concentrations of BA added to MS medium led to callus growth. The results showed that MS medium supplemented with 1.0 mg l-1 BA and 0.2 mg l-1 NAA gave adventitious shoots directly after two months from culturing of callus. The results of the second experiment showed that nodal segments cultured in MS medium supplemented with 1.0 mg l-1 kinetin was a significantly superior on other treatments studied (0.5 mg l-1 kinetin, 0.5 and 1.0 mg l-1 BA) in number of shoots/explant, leaf length, number of leaves/shoot and leaf area of formation shoot which reached 18.60 shoot/explant, 5.38 cm, 10.60 leaves/shoot and 3.64 cm2, respectively. The results showed that kinetin was a significant superior in all vegetative characteristics of shoots compared with BA.