Optimization Plant Growth Regulation Type and Culture Medium Salts in the Micropropagation of Syngonium (Syngonium podophyllum L.)

Ornamental foliage plants are commonly used for beautifying indoor spaces. Consequently, determining the best method of mass propagation in a short time, is necessary for these plants. For this purpose, an experiment was designed and performed to micropropagate the Singonium ornamental plant.

For the first stage, the effect of different plant growth plant growth regulators on the regeneration of nodule explants was evaluated. In this experiment, 1 cm nodal explants were placed in semi-solid MS culture medium containing different concentrations of BA and Kin (0, 1, 2, 3 and 4 mg/l) in combination with 0.2 mg/l IAA. This experiment was performed as a factorial based on a completely randomized design with four replications. The first factor included different types of cytokinin (BA and Kin) and the second factor included different concentrations (0, 1, 2, 3 and 4 mg/l). In the second stage, the effect of different types of culture medium and its different concentrations on plantlet proliferation was investigated. This study was performed as a factorial experiment based on a completely randomized design with five replications. The first factor included the type of culture medium (MS and B5) and the second factor was the different concentrations of culture medium (0.5 and 1). In the third stage of the experiment, the acclimation of in vitro plantlet was investigated. This experiment was performed as a completely randomized design with three replications. The experimental treatments included different culture media: vermiculite, peat moss, vermiculite + peat moss, perlite + peat moss, perlite, coco peat + vermiculite, coco peat + perlite, coco peat and rock wool.

According to the results of the first experiment, it was found that the use of cytokinin in MS culture medium is effective on plant regeneration. The highest number of regenerated plantlet was observed in culture medium containing 4 mg/l BA with 0.2 mg/l IAA. It is noteworthy that with increasing BA concentration in the culture medium, the plant height decreased, but in contrast, the number of produced plantlets increased. Benzyl aminopurine (BAP) has been introduced as the most important and effective cytokinin in inducing and increasing branching in plants. Research has shown that the use of external benzyl adenine affects plant growth by affecting plant cells or by controlling the accumulation of a number of cytokinin compounds. As a result, the use of cytokinins in culture medium under in vitro culture conditions is necessary to induce and increase cell division. According to the second experimental results, produced plantlets in MS culture medium had higher height, number of roots and root length compared to B5 culture medium. Results also demonstrated that the use of ½ MS in the propagation stage of this plant is appropriate due to the improvement of growth traits such as plantlet height and root length. The use of optimal and suitable culture medium is very effective in the success of plant micropropagation. In the present study, the use of MS culture medium showed better performance compared to B5 culture medium. The appropriate amount of components, better ion strength and more minerals in this culture medium compared to B5 culture medium are probably the factors influencing its superiority in in vitro culture. In the acclimation stage, the use of vermiculite + peat moss culture medium led to 100% adaptation of plants and improvement of growth traits in the plant.

The results showed that the type and concentration of cytokinin had a significant effect on the most of the evaluated parameters. With increasing the concentration of cytokinin in the culture medium, the number of regenerated plantlet was increased, but on the other hand, the height of regenerated plantlet also decreased. The use of culture medium containing BA compared to KIN had a more pronounced effect on increasing the number of regenerated plantlets. Application of MS medium compared to B5 medium was more effective in increasing plantlet height, root length, number of roots and number of produced plantlets. Also, half-strength MS medium, increased plantlet height and root length. Therefore, at this stage of propagation, the application of ½ MS culture medium is recommended. In the acclimation stage, it can be stated that the use of vermiculite substrate in combination with peat moss is a suitable option considering 100% compatibility of syngonium plantlets and improvement of growth traits in comparison with other substrates.