Effect of Spirulina platensis extract on growth potential of in vitro culture pear

Abstract

Pears are among the most economically important fruits in the world that are grown in all temperate zones. ‘Le-Cont’ rootstock pear is one of the gene sources used to improve fruit productivity, rootstock resistance, and tolerance to biotic and abiotic stresses. Traditional propagation of pear. Pear is time-consuming and limited by a short growing season and hard winter conditions. Therefore, in vitro propagation is a suitable alternative method. Murashige and Skoog medium (MS) and spirulina platensis extract at 5,10 and 20 % supplemented with different concentrations (0.25, 0.5 and 1.0 mg/l) of 6-benzyladenine (BA) and kinetin (Kin), individually or in combination with them. Treatments were used for in vitro shoot proliferation. Nodal segments were used as explants. MS medium augmented was 3mg/l 6-benzyladenine (BA) plus 20 % Spirulina platensis extraction then used for shootlets proliferation of micro-shoots. A combination of 3 mg/l BA and 20 % Spirulina platensis as a growth media resulted in a significant improvement in shoot proliferation. This combination produced the highest number of shoots (2.8 per explant) and leaves (6.3 per explant) similar with those containing MS media plus 20% extraction (2.9 per explant) and leaves (6.8 per explant). The longest shoots (2.97 cm) were obtained in each previous treatment. However, these shoots were similar with those produced from classical multiplication by MS according to ISSR analysis which scored 89.1 % of mono morphism percentage and 10.1 % polymorphism. The ISSR analysis shows the highest similarity index percentage for P5-P9 0.986301.