Effect of Different Concentrations of Indole Butyric Acid and Benzyl Adenine on the Regeneration of Raspberry (Rubus idaeus.) in vitro

Raspberry (Rubus idaeus L.) is most important small fruits in the world with a good color and taste. The potential for optimum off-season production under greenhouse conditions improved its commercial value. In-vitro tissue culture is one of the methods for large-scale and uniform propagation of raspberries, where the type and concentration of employed growth regulators are crucial to complement and accelerate growth. Therefore, the aim of this study was to investigate the effect of different concentrations of benzyladenine and indolebutyric acid on direct regeneration of the raspberry lateral bud.

Red raspberry bushes cv. September were used for this experiment. The experiment was carried out a factorial experiment in a completely randomized design with four replications and each replication with five explants at Sari University of Agricultural Sciences and Natural Resources. Uniform lateral bud explants after disinfection placed in culture medium containing benzyladenine at three levels of 0, 0.4 and 1 mg L-1 and indolebutyric acid at three levels of 0, 0.1 and 0.5 mg L-1 in controlled environmental conditions and finally traits such as leaf number, node number, root number, root length and ect as well as photosynthetic pigments were measured.

The results of this study showed that simultaneous use of different concentrations of benzyladenine and indolebutyric acid growth regulators in the culture medium of raspberry explants had a positive effect on a number of studied traits. The use of high concentrations of benzyladenine increased traits such as leaf number, number of node, number of internode, leaf length, lamina length. Also, the use of benzyladenine with high concentrations of indolebutyric acid increased explant size and petiole diameter. Examination of explant root length and number showed that increasing benzyl adenine concentration decreased these traits, but the use of indolebutyric acid at higher levels increased root length and number. Evaluation of the effect Results of benzyladenine and indolebutyric acid on photosynthetic pigments indicated that the increase of these regulators increased chlorophyll a, chlorophyll b and carotenoid in traeted explants.

In general, the use of benzyladenine plus indolebutyric acid was effective depending on the concentration used, was effective in improving the vegetative traits of the plantlets of the raspberry lateral bud explants, but indolebutyric acid alone only affected rooting at high concentrations. So that the use of indolebutyric acid increased root number and length at higher levels that suggesting a functional contrast between these two growth regulators. Investigating the effect results of benzyladenine and indolebutyric acid on photosynthetic pigments resolved the ambiguity of how enhancing these regulators led to synergized and improved explant size. It was observed that with increasing concentrations of these regulators, increased in important photosynthetic pigments such as chlorophyll a, chlorophyll b and carotenoid was obvious. Importantly, the tissue and organs of raspberries are more susceptible than black berry and respond to lower concentrations of this growth regulators.