Preliminary results on the use of meta-Topolin, an a efficient cytokinin for zeatin replace on olive micropropagation

Although olive growing is practiced for centuries in the Mediterranean basin, even today mass propagation of olive trees (Olea europaea L.) finds impediments. The in vitro culture presents a series of advantages, but differently of other species micropropagation of olive isn’t a commercially practice because of limits, as its requirement of zeatin, a cytokinin of high cost that provides obtaining satisfactory multiplication rates. The present study aimed to evaluate the possibility of total or partial substitution of zeatin by another cytokinin called meta-topolin. The work was developed in the Laboratory of in vitro culture of Università degli Studi di Perugia, Italy, and was evaluated the in vitro proliferation of shots of olive (cultivar Moraiolo).The experiment consisted in definition of five treatments comprise of quantitative combinations between meta-topolin and zeatin respectively, as following reported: T1: 0 + 4 mg L-1, T2: 1 + 3 mg L-1, T3: 2 + 2 mg L-1, T4: 3 + 1 mg L-1 and T5: 4 + 0 mg L-1. Each treatment was composed of three replicates with 10 explants. All cultures were inoculated in Olive medium (OM) and were kept in a controlled environment, with temperature 21±2°C, photoperiod 16 hours light at a luminous frequency of 40 μE m-2 sec-1, for 45 days. Elapsed this period, vitality, number and length of shoots, number of leaves, shoot and callus fresh weight, total dry weight of explant and multiplication rate were evaluated. A statistic difference for shoot length and fresh weight of shoot was monitored, when the use of higher concentrations of meta-topolin in treatments T3, T4 and T5 favored the growth and fresh weight of shoots. It concludes with this initial test that it’s possible replace zeatin by meta-topolinin the proliferation phase of olive cultivar Moraiolo.