Study of the effects of the explant type and the hormonal composition of the culture medium in the micropropagation of strawberry (Fragaria × ananassa Duch., cvs. Pajaro and Paros)

Micropropagation is one of the most important applications of plant tissue culture. Using the micropropagation for strawberry propagation, in addition to producing many plants, can meet the growing need for healthy and disease-free plants. In this study, the in vitro propagation of two strawberry cultivars (cvs. Paros and Pajaro) was investigated using Murashige and Skoog (MS) culture medium. In each cultivar, the effects of hormonal composition of the culture medium (1 mg l-1 BAP and 0.5 mg l-1 NAA + 0.2 mg l-1 BAP) and explant type (nodal bud and terminal bud (big and small) of runners) were studied. All explants provided from the glass greenhouse-grown plants. The in vitro cultures were subcultured three times at an interval of 30 d. The results of analysis of variance showed that the effect of explant type was significant for three studied traits (the number of plantlets per explant, the average height of plantlets per explant and the number of roots per explant). The best results for all three traits were obtained using nodal buds. Subculturing significantly increased the number of regenerated plantlets, so that in the third subculture, seven plantlets were obtained from each explant. In general, the results of the present study showed the good efficiency of in vitro culture of nodal buds for the micropropagation of two commercial strawberry cultivars, Pajaro and Paros.