Comparative Elimination of Begomoviruses in Cassava Meristems and Axillary Buds

Aim: The production of healthy cuttings from a local cassava cultivar for cassava mosaic control.

Study design: The study was carried out at the In Vitro Culture Laboratory using the techniques of thermotherapy and culture of tissues and explants in a specific medium.

Place and duration: The study was carried out at the Laboratory of Biological and Agronomic Sciences for Development at the University of Bangui, Central African Republic from December 2017 to June 2018.

Methodology: A variety of cassava called six-month very susceptible to mosaic was used for this work. The cuttings used were infected by Cassava Mosaic Begomoviruses (CMBs) with high severity. It were subcultured in a room under the heat of 37 ° C to 40 ° C for two weeks. Explants and meristems were taken from the stems and the apices, respectively. These collected materials were treated and seeded on appropriate culture media. After the plants produced in vitro were acclimatized and the leaves were removed to check their phytosanitary state by the PCR technique.

Results: The rate of emergence of the acclimatized plants and the expression of the disease on the microplants were evaluated. The results show that 75% of the weaned vitro plants recovered under acclimatization. In addition, the acclimatized plants left growing in the greenhouse for four months remained asymptomatic. Molecular analysis by PCR showed that begomoviruses were not detected on meristem samples unlike samples from stem fragments.

Conclusion: The combination of thermotherapy technique associated with the culture of meristems constitutes an effective means useful for the sanitation of infected plant material.