Detection of the Cape St. Paul wilt phytoplasma in coconut palms in Ghana through the combination of visual symptoms assessment and molecular diagnosis using a secA gene based assay.

Abstract

Lethal Yellowing-type diseases of coconut have destroyed thousands of coconut palms globally, and in Ghana the disease [Cape St. Paul wilt disease (CSPWD)] is considered as the single most important factor affecting the coconut industry. To improve the diagnostics available for CSPW detection, a ribosomal and a non-ribosomal-based assay were assessed for their effectiveness in diagnosing CSPWD. PCR diagnoses and observation of symptom development were carried out twice per year over three years to study the fate of infected palms and the pattern of disease spread. Comparison of the effectiveness of different PCR assays at detecting CSPWD-infection showed a comparable performance of a single round secA-based assay to nested PCR using primers targeting ribosomal DNA sequences. The study showed that all infected palms eventually died from infection and analysis of the location of palms becoming infected showed no clear pattern in the spread of infection.