EFFECTIVENESS OF SOMATIC EMBRYOGENESIS IN ELIMINATING THE CASSAVA MOSAIC VIRUS FROM INFECTED CASSAVA (Manihot Esculenta Crantz) PLANT MATERIALS

Abstract

Cassava (Manihot esculenta Crantz) is a staple food for many people in the tropical regions. However, yield of cassava has reduced of late due to high incidence of cassava mosaic disease (CMD) which is caused by the cassava mosaic virus (CMV). This necessitated the study on the production of disease free cassava materials from CMD cassava plants through somatic embryogenesis. CMV infected cassava leaves were cultured for callus tissue induction and somatic embryos (SE) generation on modified MS media supplemented with 2, 4–D. The SE maturation was carried out on modified MS media supplemented with Benzyl Amino Purine (BAP). Callus tissue initiation and induction started ten (10) days after plating (DAP), SE were generated 35 DAP and survival rate of explants was 90.2 %. Maturation of SE occurred 60 DAP and the number of somatic embryos per explant ranged from 5 – 14. Polymerase Chain Reaction (PCR) and Enzyme Linked Immunosorbent Assay (ELISA) were used to detect the presence of CMV on leaves, callus tissues and SE. East African Cassava Mosaic Virus (EACMV) and African Cassava Mosaic Virus (ACMV) were two different strains of CMV detected in the leaf, callus tissue and SE from CMD cassava explants. The SE that was generated from CMV infected leaves of cassava showed 87.5% virus free with the PCR technique of viral particle detection. The outcome of the study demonstrated the effectiveness of somatic embryogenesis in eliminating the ACMV from infected materials and EACMV from infected cassava plants to produce viral free planting materials.