Journal of Plant Pathology (2007) 89, p. S31a (Bellardi et al.)

M.G. Bellardi, A. Benni, S. Davino, M. Davino and G. Bozzano (2007)
Survey of virus diseases of Polygala myrtifolia in Liguria
Journal of Plant Pathology 89 (3, Suppl.), S31-S31
Poster Presentation at S.I.Pa.V XIV National Meeting - Perugia, Italy 19-21 Sept. 2007
Abstract: Polygala myrtifolia L. (myrtle-leaf milkwort; Polygalaceae) is an attractive evergreen shrub, originating from South Africa, recently introduced in Liguria (northern Italy) where it is propagated by cuttings. In 2006, severe virus-like symptoms consisting of leaf mosaic, narrowing of the leaf blades, yellow spots, vein yellowing, white necrotic spots, rings and line-patterns on oldest leaves and variegation on younger leaves, were observed on plants growing in different nurseries in the Imperia province. No flower symptoms were observed. Since in 2002 Polygala was reported in Italy as a new natural host of Cucumber mosaic virus (CMV), preliminary PAS-ELISA tests were carried out to check for the presence of this virus. CMV alone was detected in association with chlorotic mosaic symptoms. In plants showing yellow veins and spots, potyvirus-like filamentous particles were observed under the electron microscope. In IEM ('decoration') and PAS-ELISA tests, this virus proved to serologically related distantly to Soybean mosaic virus and strongly to Bean yellow mosaic virus. P. myrtifolia showing rings and line-patterns was positive (PAS-ELISA) to the Batavian lettuce strain of Tomato spotted wilt virus (TSWV: PVAS-450; American Type Culture Collection, Manassas, VA, USA). RTPCR was done using specific primers for the CP gene of TSWV (forward 5'-TTA ACT TAC AGC TGC TTT-3'; reverse 5'-CAA AGC ATA TAA GAA CTT-3'). All samples yielded DNA fragments of the expected size (823 bp). Considering that in 1940 wild Polygala in South Africa was reported as a probable host of tospoviruses (unconfirmed report), our study establishes P. myrtifolia as a new natural host for TSWV.
Database assignments for author(s): Maria Grazia Bellardi, Salvatore Walter Davino

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Cucumber mosaic virus	Polygala (crop)	Italy
	Orthotospovirus tomatomaculae	Polygala (crop)	Italy