Molecular diagnostics of groundnut rosette disease agents in Uganda: Implications on epidemiology and management of groundnut rosette disease
Loading...
Date
2017
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of plant breeding and crop science
Abstract
The objective of this study was to use molecular diagnostic tools to detect the agents of groundnut
rosette disease (GRD) to guide in varietal development and disease management. Samples were
collected from both GRD infected and healthy plants and sites geo-referenced. RNA extraction, cDNA
synthesis, polymerase chain reaction (PCR) amplification, electrophoresis, staining and visualization
were performed according to standard procedures. Molecular diagnosis of the samples showed various
combinations of the GRD agents, some in isolation and others a combination of two or three agents.
This distribution is attributed to dependence on the aphid feeding behaviour and pathogenicity of GRD
agents. Chlorotic and green rosette symptoms were observed throughout the sampling sites signifying
the presence of satellite RNA (sat-RNA) variants. Some plants showing GRD symptoms tested negative
for GRD, whereas some healthy-looking plants tested positive for the GRD complexes pointing to the
ineffectiveness of phenotypic screening and the need for a molecular diagnostic tool that detects all
three GRD agents both in absence or presence of disease symptoms. The absence of groundnut rosette
assistor virus (GRAV) in some symptomatic samples signifies that they are epidemiologically dead end
sources since GRV and sat-RNA must be packaged within the GRAV coat protein to be aphid
transmissible. Oyado (Cassia obtusifolia) tested positive for all the GRD agents making it a potential
alternative host. There is an urgent need for validation of the phenotypic screening with molecular tools
in efficient diagnosis of the multi-pathogenic GRD in guiding both plant breeding and pathology work.
Description
Keywords
Arachis hypogaea L., Groundnut rosette disease, Molecular diagnostics, Polymerase chain reaction (PCR)
Citation
Okello, D. K., Ugen, M. A., Tukamuhabwa, P., Ochwo-Ssemakula, M., Odong, T. L., Adriko, J., ... & Deom, C. M. (2017). Molecular diagnostics of groundnut rosette disease agents in Uganda: Implications on epidemiology and management of groundnut rosette disease. Journal of plant breeding and crop science, 9(5), 63-70. DOI: 10.5897/JPBCS2016.0630