Elimination of African cassava mosaic virus (acmv) in cassava (manihot esculenta crantz) using Meristem culture associated to thermotherapy

Cassava (Manihot esculenta, crantz), is an important root crop in the tropics and substropics of Africa and Latin American. It is vegetatively propagated crop. Due to the following cycles of propagation, viruses are accumulated, which contributes to the decline of cassava yield and quality. Stem cuttings of four cassava accessions Six-mois, Rendre, yalipé and M61/033 were collected in experimental field and have brought to laboratory. Infected plants were thermotherapy treated by incubation of plants at 42°C/day and 38/night for 2 weeks. The shoot sproot leaves from thermotherapy are symptoms free of ACMV, shoots apicals were taken for meristem tip culture and allowed to grow in vitro.   Leaves from thermotherapy were also taken for PCR test  to confirm the success of ACMV elimination on thermotherapy only compare to  meristem tip culture associated to thermotherapy. Clean plants material were acclimated and taken to the experimental field. A total of 637 meristems were isolated in vitro, 512 (80,32 %) were regenerated. A regeneration percentage of 80 % for Yalipe accession, 82 % for M61/033 accession, 85,2 % for Rendre accession and 92,3 % for Six-mois accession. A PCR test has confirmed 95 % of virus free plants from meristems tips culture associated to thermotherapy, otherwise 99 % percent of plants from thermotherapy treatment without meristems tips culture were ACMV virus infected. A total of 712  explants nodals virus free were submitted to subculture and accimated, 363 plants of African Cassava Mosaic Virus free were obtained and transfered to experimental field.