GENERATION OF CASSAVA MOSAIC DISEASE FREE CASSAVA (Manihot esculenta Crantz) MATERIALS FROM INFECTED CASSAVA PLANT MATERIALS THROUGH SOMATIC EMBRYOGENESIS

Abstract

Cassava (Manihot esculenta Crantz) is a staple food for many people in the tropical regions. However, yield of cassava have reduced of late due to high incidence of cassava mosaic disease (CMD) which is caused by the cassava mosaic virus (CMV) in the tropics. This necessitated the study on the production of virus-free planting materials from CMD-infected 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 BAP. Callus tissue initiation and induction started ten (10) days after plating (DAP) and SE were generated 35 DAP. Survival rate of explants was 90.2 %, with 85.6 % callus tissue induction from which 72.4 % of the induced callus tissue generated SE. Maturation SE occurred 60 DAP and the ~umber of somatic embryo 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 infected 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. Therefore, the study concluded that somatic embryogenesis effectively eliminated ACMV and EACMV from infected cassava plants to produce viral free planting materials.