Effect of various phenol inhibitors and explant size on meristem culture in the Gavieta variety of Fragaria ananassa

Strawberry (Fragaria ananassa cv. Gavieta) are infected with several important viral diseases. In vitro culture of the meristem-tip is a valuable method in recovering pathogen-free plants and micropropagation of such crops. In this study, the effects of meristematic dome size, medium type and phenol inhibitors (AC, PVP and ascorbic acid) were investigated on the shoot tip culture of strawberry. Also the effect of plant growth regulators on shoot elongation was investigated. As the base medium, shoot tips were cultured on the MS media supplemented with 1 mg/l 6-benzylaminopurine (BAP) and 0.2 mg/l indole-3-acetic acid (IAA). The highest regenerated shoots were obtained with the meristematic dome with two leaves. The type of medium (liquid, semi-solid, and solid) significantly affected shoot tip proliferation, and the highest percentage of shoots were observed in the semi-solid medium. In the semi-solid medium all meristems were regenerated and produced more shoots with 8.55 mm length. Application of the phenol-absorbing and antioxidant compounds in the culture medium improved shoot induction and shoot performance. The best result was obtained in the medium supplemented with 500 mg/l polyvinylpyrrolidone (PVP) with 5 shoots, in which browning and explant death were avoided by absorbing phenolic substances from the explant.