PCR-Based Diagnosis of Cassava Mosaic Begomoviruses and DNA Satellites in Cassava Plants in Northern Ghana

Cassava mosaic begomoviruses and DNA satellites are major threats to cassava production. In this study, 55 cassava farmers’ fields in Northern Ghana were randomly assessed for cassava mosaic disease (CMD) incidence, severity, adult whitefly counts, and cassava mosaic begomoviruses. Also, DNA satellite status was determined for 203 asymptomatic and symptomatic cassava leaf samples using polymerase chain reaction involving primers that detect Begomovirus manihotis (formerly African cassava mosaic virus; ACMV) and Begomovirus manihotisafricaense (formerly East African cassava mosaic virus; EACMV) and DNA satellites. CMD was recorded in 50 (90.9%) out of the 55 farms surveyed. Incidence of CMD ranged from 3.33% to 69.65%, with a mean of 46.3% in Northern Ghana. Also, CMD severity ranged from 2.0 to 3.1 and averaged 2.5. Adult Bemisia tabaci counts were generally low. Out of 168 symptomatic cassava leaf samples, ACMV only was detected in 64.3%; EACMV only was detected in 15.5%, and EACMV–ACMV coinfection was detected in 20.2% of these leaf samples. Out 63 EACMV positive cassava leaf samples, satIII and satII were, respectively, detected in 85.7% and 77.8% samples. This study indicates the presence of Begomovirus manihotis, Begomovirus manihotisafricaense, and satellites (satII and satIII) in Northern Ghana. The data generated by this study could serve as potential resource in modeling to predict CMD and related satellites spread both in and outside Ghana.