What may indicate infection
Older guides listed mosaic patterns, discolouration and growth inhibition, but also emphasised the difficulty of diagnosis. These are non-specific symptoms. Physiological damage, feeding injury and some developmental changes produce a similar appearance. The absence of such symptoms does not exclude a virus. The plant's condition must therefore be described separately from the diagnostic result. [Fleischer and Schütz 1978, pp. 185–186] [Seneta b.d., pp. 106–108] [Evallo et al. 2021]
Cactus virus X and mixed infections
Cactus virus X, CVX, an RNA virus belonging to the potexviruses, has an important place in the literature on cacti. The review by Evallo, Taguiam and Balendres discusses symptoms, hosts and detection methods. Infections can also be asymptomatic. The coexistence of several viruses makes it harder to attribute a particular symptom to one of them. [Evallo et al. 2021]
Maliarenko and Mudrak studied both fasciated forms and ordinarily growing rootstocks. The detected particles were assigned to virus groups from their microscopic appearance and biological assays. This is a valuable historical observation, but not molecular confirmation of every species name or proof that infection caused cristata. [Maliarenko and Mudrak 2013]
How a diagnosis is confirmed
RNA viruses are detected using methods that include reverse transcription, such as RT-PCR. This step distinguishes RNA testing from ordinary PCR on DNA. A result is reliable within the scope of the virus tested and the method used. A negative CVX test does not exclude all other viruses. The testing request should include the plant name, a description of symptoms, grafting history and whether the scion, rootstock or both components are being tested. [Evallo et al. 2021] [Fleischer and Schütz 1978, pp. 185–186]
Limiting transmission
A mechanically transmitted virus can pass with sap during cutting and grafting. A suspect plant is not propagated to “check whether the offset will be healthy” or used as a rootstock for valuable material. Propagation material should have a known origin. Testing is needed for lines that require confirmed health. Separating a suspect specimen limits contact with the rest of the collection. [Evallo et al. 2021] [Fleischer and Schütz 1978, pp. 185–186]
Cleaning tools must precede effective disinfection, because remaining debris hinders contact between the agent and the surface. No single unverified home recipe guarantees inactivation of all viruses. The protocol is selected for the identified pathogen and the tool material. Grafting a healthy-looking fragment of an infected plant is not a method of treating the virus. [Fleischer and Schütz 1978, pp. 185–186] [Maliarenko and Mudrak 2013]
What virus control means in a collection
A routine fungicide or insecticide does not remove a virus from infected tissues. Management focuses on healthy starting material, hygiene and eliminating sources of infection. With confirmed infection and no available method for cleaning the material, the infected plant is removed from propagation use. A decision to retain an isolated specimen is made consciously, without labelling its vegetative offspring as virus-free. [Fleischer and Schütz 1978, pp. 185–186] [Seneta b.d., pp. 106–108]
In vitro cultures and regeneration from small meristems may form part of a specialist sanitation programme, but producing a plant in a sterile vessel does not itself prove virus elimination. The microbiological purity of the medium and the absence of a virus in the regenerant are different properties. Details are described in the chapter on in vitro cultures. [Szychowski 2010]
Virus sequences in cactus data
In 2025, Baek and colleagues described new virus sequences related to Bevemovirus, reconstructed from public cactus RNA data. One of the hosts analysed was Maihueniopsis conoidea. Genome structure and relationships were compared, and agreement in some virus–host relationships led the authors to consider vertical transmission. The sequence study did not include an experiment inducing symptoms in this species. [Baek et al. 2025]
Prepared from the cited studies and supplied book excerpts. Historical names and recommendations are distinguished from current findings. The extent of access to each publication is stated in the bibliography.
Cactus viruses in fasciated plants
Maliarenko V. M., Mudrak T. P., Cactus viruses in fasciated plants, Biologija, 2013, 59(2):213-218, doi: 10.6001/biologija.v59i2.2754
The article analyses nine samples of fasciated plants and rootstocks for the presence of viruses. Identification of the particles is based on morphology and biological assays.
A brief review of plant diseases caused by Cactus virus X
Evallo E., Taguiam J. D., Balendres M. A., A brief review of plant diseases caused by Cactus virus X, Crop Protection, 2021, 143:105566, doi: 10.1016/j.cropro.2021.105566
The available review abstract presents Cactus virus X, CVX. It covers symptoms, transmission routes and methods for detecting infection.
Kaktusy
[Fleischer Z., Schütz B., Kaktusy, Państwowe Wydawnictwo Rolnicze i Leśne, Warszawa, 1978, wyd. I, trans. Kabiesz Z., Prajer Z.]
Państwowe Wydawnictwo Rolnicze i Leśne, Warsaw, first edition. Translated by Zofia Kabiesz and Zbigniew Prajer. Historical and cultivation background. Names and interpretations updated separately.
Kaktusy
[Seneta W., Kaktusy, b.d., s. 99–111 (udostępniony fragment)]
The supplied book extracts come from Konrad Szychowski's private archive. The chapters describe cactus diseases, pests and damage, and historical methods of plant protection. The year and edition of this copy remain undetermined.
University of California Integrated Pest Management
Identification of plant problems and principles of integrated pest management.
Accessed 2026-10-08.
Kaktusy in vitro — cykl materiałów autorskich
[Szychowski K., Kaktusy in vitro — cykl materiałów autorskich, 2010]
Konrad Szychowski's original series dated 25 September 2010, preserved in his private archive. It describes equipment, media and establishing in vitro cactus cultures.
Expansion of the genus Bevemovirus: Novel genome discovery and evidence for virus–host co-segregation
Baek S., Hahn Y., Lee S. C., Expansion of the genus Bevemovirus: Novel genome discovery and evidence for virus–host co-segregation, Gene, 2025, 962:149573, doi: 10.1016/j.gene.2025.149573
Analysis of public transcriptomes reveals nine new virus sequences related to Bevemovirus, including in Maihueniopsis conoidea data. The authors compare genome organisation and phylogenetic trees for viruses and hosts. The hypothesis of co-inheritance derives from sequence analyses, without an experiment on the transmission route.
