In vitro culture and greenhouse acclimatization of Oncidium varicosum (Orchidaceae) with microorganisms isolated from its roots

Abstract

Sustainable production of orchids may be achieved with the use of symbiotic microorganisms that improve resistance of plants to pests and diseases and reduce the need of substrate fertilization. In this study, one fungus (F1), one yeast (Y1) and one gram-positive bacteria (B+) were isolated from the roots of the orchid Oncidium varicosum and used in the cultivation of protocorms and plantlets obtained from seeds of this species. Cultivation of protocorms in Murashige and Skoog (MS) medium enriched with sucrose and inoculated with microorganisms did not result in better development of protocorms. However, the use of plantlets in the rooting phase in MS medium without sucrose and inoculated with B+ resulted in plantlets with more leaves and roots and longer shoots and roots, suggesting synergism between microorganism and plant when sucrose is absent. The major benefits of co-cultivating plantlets and these microorganisms were observed in the acclimatization in the greenhouse. Plantlets obtained with oat meal agar medium and B+ showed the highest pseudobulb diameter, number of roots, height and fresh weight among treatments. We concluded that the application of rooting-derived microorganisms in the in vitro culture and plantlet acclimatization of Oncidium varicosum is beneficial.

Temperature and GA3 on ROS and cytogenetic stability during in vitro cultivation of strelitzia zygotic embryos

“…The in vitro germination of some species, such as Maclura tinctoria, Cocos nucifera, and Syagrus coronata, has been increased by supplying the medium with GA 3 (Gomes et al, 2010;Medeiros et al, 2015;Montero-Cortés et al, 2011). This growth regulator could be important for cell growth and elongation, leaf expansion and photosynthetic processes, as well as for the activity of important metabolic enzymes, such as nitrate reductase (Gupta;Chakrabarty, 2013, Bezerra et al, 2019. Enhancement of nitrate reductase activity may be beneficial, since this enzyme is responsible for the assimilation of nitrogen, an essential element found in many macromolecules and components of secondary metabolism, including proteins, nucleic acids, cell wall components, hormones, and vitamins (Krapp, 2015).…”

Morphophysiological responses of Billbergia zebrina Lindl. (Bromeliaceae) in function of types and concentrations of carbohydrates during conventional in vitro culture

“…Micropropagation is the most common method used for large-scale cloning ornamental horticulture plant species (Kumari et al, 2017;Naidoo et al, 2017;Bezerra et al, 2019). Among the ornamental species frequently micropropagated are bromeliads.…”

Potential Role and Utilization of Plant Growth Promoting Microbes in Plant Tissue Culture

“…Some bacteria have also exhibited good potential for application in orchid cultivation. In this sense, Bezerra et al (2020) reported positive impact of the application of rooting-derived microorganisms, especially bacterial isolate in the in vitro culture and plantlet acclimatization of Oncidium varicosum. In vitro bacterization of photinia (Photinia × fraseri Dress), another ornamental FIGURE 4 | Schematic summary of some benefits of biotization process compared to classical micropropagation process.…”

“…An effective system for the in vitro propagation of orchids must integrate the associated symbiotic fungi through biotization approach. This will allow good micropropagation and acclimatization with no apparent “transient transfer shock.” In addition, the technique of biotization could be a realistic way to produce low-cost micropropagated plantlets ( Bezerra et al, 2020 ). Some bacteria have also exhibited good potential for application in orchid cultivation.…”