Auxins and Cytokinins elicit a differentiated response in the formation of shoots and roots in Cattleya maxima Lindl and Phalaenopsis amabilis (L) Blume

Abstract

Orchids have a long period of production and need to be under the right conditions. Therefore, in vitro propagation is an alternative to reduce production time. This study aimed to determine the optimal in vitro propagation conditions in two species of orchids, Cattleya maxima Lindl. and Phalaenopsis amabilis (L.) Blume. For this goal, two experiments were carried out: multiplication and rooting, for both species. In the multiplication experiment, the treatments were differentiated according to the complement of MS (Murashige and Skoog medium), banana flour, kinetin or 6-Benzylaminopurine (BAP). Meanwhile, in the rooting experiment, the complements were banana flour, Indol-3-butiric acid (IBA), Naphthaleneacetic acid (NAA) or 2,4-Dichlorophenoxyacetic acid (2,4-D). According to the results, banana flour (50 g.L-1) increased the plantlet height in C. maxima (multiplication) and P. amabilis (rooting). Kinetin (0.003 g.L-1) and BAP (0.005 g.L-1) increased the number of shoots and leaves in C. maxima, in multiplication experiment. In rooting experiment, NAA (0.003 g.L-1) increased significantly the number of leaves in C. maxima. The root formation was notably stimulated by banana flour in both species. Likewise, 2,4-D (0.003 g.L-1) can cause phytotoxic effects and inhibit root formation. In conclusion, C. maxima was more robust than P. amabilis since in all studied variables the former presented the highest values. Furthermore, C. maxima responds adequately to application of kinetin and BAP to increase the aerial part of the plant, however, they inhibit the root formation. In contrast, kinetin and BAP do not limit root growth in P. amabilis.

Plant growth regulators and organic additives on the proliferation of protocorm-like bodies and plantlet regeneration of Cattleya gaskelliana (N.E.Br.) B.S.Williams

“…The highest number of adventitious shoots (4.1 ± 0.49 shoots per explant) was recorded in the medium supplemented with 50 g L -1 banana puree and 2.0 mg L -1 IBA (Table 5). While studying the effect of auxins and cytokinins on the formation of shoots and roots in Cattleya maxima seedlings, we found that the application of IBA stimulates the formation of a large number of shoots and leaves at the rooting stage (Saravia-Castillo et al, 2022). Indole butyric acid (IBA) also positively affects the multiplication rate compared to NAA (Xu, Beleski, & Vendrame, 2022), which matches the results of our study.…”