First report of Beet necrotic yellow vein virus in South Africa
During the 2014 and 2015 production seasons, hairy roots, root stunting symptoms, and yellowing of leaves, were observed on red table beet (Beta vulgaris cv. ‘Red Ace’) in commercial fields of one farm located in Bonnievale (Western Cape province), South Africa. Root samples were collected from symptomatic plants and tested in the laboratory (electron microscopy, RT-PCR, sequencing). Results confirmed the presence of Beet necrotic yellow vein virus (BNYVV, EPPO A2 List – rhizomania) in diseased roots and resting spores of the fungus-like vector, Polymyxa betae, were observed in root epidermal cells. In addition, seeds of four cultivars of red table beet were planted in bags with soil collected from the contamined fields, and both P. betae and BNYVV could be found in resulting plant roots. It is stressed that surveys should be carried out in beet-growing regions of South Africa and that measures should be taken to prevent the spread of BNYVV.
The situation of Beet necrotic yellow vein virus in South Africa can be described as follows: Present, first detected in 2014-2015 in red table beet in one farm (Western Cape province).
Sources
Roberts R, Botha WJ, Wolfaardt JP, Jooste AEC (2016) First report of Beet necrotic yellow vein virus (BNYVV) on red table beet in South Africa. Plant Disease 100(5), p 1025.