Orchids are ornamental plants that are infected by many viruses. They can be transmitted by mechanical inoculation, by the reproduction of infected plants or by contact between the virus and a healthy plant. Viruses reduce orchid vigour and population numbers, and have negative economic consequences for cultivated orchids. The most widespread are Cymbidium mosaic virus (CymMV) and Odontoglossum ringspot virus (ORSV). The most commonly used test for detecting viruses in cultivated orchids is the ELISA test, which is mainly used by commercial laboratories. DAS- and DASI-ELISA are in use. There are also quicker tests that can be carried out in the greenhouse. An example is the Agdia ImmunoStrip test, which can be performed in about 15 minutes. It can check for the presence of several viruses. Once the presence of the virus is detected, it can be removed using various techniques to grow virus-free orchids. Elimination can be achieved using in vivo thermotherapy and various in vitro culturing techniques. These are meristem culture, thermotherapy, chemotherapy, cryotherapy, electrotherapy, protocorm-like body (PLB) selection and thin section (TS) culture. In three original scientific papers, we will trace the different plant tissue culture techniques for growing virus-free plants and their success. In the first paper, out of 100 meristems isolated, only 17 successfully developed PLBs and from the 3rd subculture onwards, 18 PLBs lines were virus-free. In the second paper, 148 of 172 inoculated meristems were virus-free. The survival rate of the different meristem sizes dropped to 0-50% after one month. In the last paper, orchid seeds were used as in vitro culture cuttings. The researchers subcultured individual protocorms, meristem tips and artificial seeds on four different media.
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