Elimination of cymbidium mosaic virus and odontoglossum ringspot virus from orchids by meristem culture and thin section culture with chemotherapy

Abstract

Most commercially cultivated orchid plants are generally infected with cymbidium mosaic virus (CyMV) and odontoglossum ringspot virus (ORSV). Two methods were used in order to generate virus-free plants: meristem culture and thin section culture with chemotherapy. Meristems (0.10 mm to 1.00 mm) were excised from infected axillary shoots of an infected monopodial orchid hybrid (Mokara Char Kuan 'Pink') and cultured in modified Vacin and Went medium. Only larger meristem explants survived and the regenerated plantlets remained virus-infected. In contrast, high percentages of virus-free plantlets were obtained from thin section cultures of infected plantlets and protocorm-like bodies with ribavirin treatment. Interestingly, regenerants from thin section cultures without ribavirin treatment were also found to be free from CyMV and ORSV. All plantlets were tested by enzyme-linked immunosorbent assay (ELISA) and/or polymerase chain reaction (PCR).

Review. Elimination of viruses in plants: twenty years of progress

“…In fact, the principal target of antiviral activity of these molecules is the inosine monophosphate dehydrogenase, an enzyme that catalyzes the conversion of inosine 5'-monophosphate (IMP) in xantosine 5'-monophosphate and is able to alter the pathway for the production of guanosine mono-di-and triphosphate. The presence of its inhibitor acts on this Weiland et al, 2004;Panattoni et al, 2006Panattoni et al, , 2007aSkiada et al, 2009bJames et al, 1997;Cieslinska, & Zawadzka, 1999;Cieslinska, 2002;O'Herlihy et al, 2003Janeckova, 1993Gabova, 1995;Chen & Li, 2001;Chen & Lu, 2000Kolbanova et al, 2004Iwanami & Ieki, 1994Cieslinska, 2003Conrad, 1991Green et al, 1992;Park et al, 1994;Kim et al, 1996;Truskinov & Rogozina, 1997;Faccioli & Zoffoli, 1998;Horackova, 1998;Nascimento et al, 2003;Fang et al, 2005Loi et al, 1991Schulze & Kluge, 1994Kim et al, 1994Xu & Niimi, 1999;Xu et al, 2000Ram et al, 2005Bertaccini et al, 2004Ramírez-Malagón et al, 2006Xu et al, 2004Lim et al, 1993;Toussaint et al, 1993;Fletcher et al, 1998;Freitas & Rezende, 1998;Yap et al, 1999;Fletcher & Fletcher, 200...…”

Tissue disinfection for preparation of Dendrobium in vitro culture

“…The use of multiplex RT-PCR could be used for simultaneous detection of CymMV, ORSV and Orchid fleck virus (OFV) in Dendrobium and another orchid genus (Ali et al 2014, Kim andChoi 2015). Using meristem (0.1 to 1 mm) culture of Mokara Char Kuan 'Pink', Lim et al (1993) observed that regenerated plantlets from the culture of larger meristems remained infected by CymMV and ORSV while TLCs of infected plantlets and PLBs, when treated with ribavirin, were free of these viruses. Interestingly, few papers described or show advances in studies of these microorganisms, although contamination problems continue to be observed in commercial laboratories and commercial orchid nurseries (Khentry et al 2006a(Khentry et al , 2006b(Khentry et al , 2007 Fig.…”

“…hillii. Virus infection is another problem in orchids (Khentry et al 2006b) and the elimination of important viruses such as Cymbidium mosaic virus (CymMV) and Odontoglossum ringspot virus (ORSV) is possible by seedling culture (Khentry et al 2006b), thin section culture (Lim et al 1993) and PLB culture (Chanprame et al 2011) combined or not with chemotherapy using ribavirin treatment. For example, Khentry et al (2006a) observed the occurrence of CymMV (but not ORSV) in six orchid genera, including in in vitro micropropagated plantlets of several Dendrobium cultivars ('Chanel', D. 'Chao Praya', D. 'Pravit White', D. 'Sakura' and D. 'Shawin White'), which displayed high rates of infection.…”

The morphogenetic capability and the viability of regenerants in micropropagated orchid hybrids infected with viral pathogens

“…Odontoglossum mosaic persisted (Figs 5a and b), even when in the micropropagation stage dichlorophenoxyacetic acid (known for high mutation rates) was included. Perhaps such method had been effective in eliminating viral RNA from infected vegetative tissues of C. waltersiana × C. schönbrunennsis and Cattleya bonanse × C. schönbrunnensis (Ishii 1974, Albouy et al 1988, Freitas-Astua and Rezende 1988, Lim et al 1993, Freitas-Astua 2003, Jiang et al 2005. Further studies are needed to elucidate this complex phenomenon.…”