Polygala myrtifolia L. (myrtle-leaf milkwort; Polygalaceae) is an attractive evergreen shrub, originating from South Africa, recently introduced in Liguria region where it is propagated by cuttings. In 2006, severe virus-like diseases consisting of: leaf mosaic, narrowing of the lamina, yellow spots, vein yellowing, white necrotic spots, rings and line-patterns on oldest leaves and variegation on the younger ones, were observed on plot plants growing in different ornamental nurseries in Imperia province. No flower symptoms were observed. Since in 2002 Polygala has been indicated in Italy as a new natural host of Cucumber mosaic virus (CMV), preliminary PAS-ELISA tests were carried out to verify this virus presence. CMV alone was detected associated to chlorotic mosaic symptoms. In plants showing yellow veins and spots, potyvirus-like filamentous particles were observed at electron microscope. In IME (“decoration”) and PAS-ELISA tests, this virus appeared partially serologically related to Soybean mosaic virus and strongly to Bean yellow mosaic virus. P. myrtifolia showing rings and line-patterns was positive (in PAS-ELISA) to Batavian lettuce strain of Tomato spotted wilt virus (TSWV: PVAS-450; American Type Culture Collection, Manassas, VA, USA).) RT-PCR technique was employed using specific primers for 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 of 823 bp. Considering that in 1940 wild Polygala in South Africa has been indicated as a probably host for Tospoviruses (unconfirmed report), our study establishes P. myrtifolia as a new natural host for TSWV.
SURVEY ON VIRUS DISEASES AFFECTING POLYGALA MYRTIFOLIA IN LIGURIA / M.G. Bellardi; A. Benni; S. Davino; M. Davino; G. Bozzano. - STAMPA. - (2007), pp. 35-35. (Intervento presentato al convegno XIV Nazionale della Società Italiana di Patologia vegetale tenutosi a Perugia nel 18-21 settembre 2007).
SURVEY ON VIRUS DISEASES AFFECTING POLYGALA MYRTIFOLIA IN LIGURIA
BELLARDI, MARIA GRAZIA;BENNI, ALESSANDRO;
2007
Abstract
Polygala myrtifolia L. (myrtle-leaf milkwort; Polygalaceae) is an attractive evergreen shrub, originating from South Africa, recently introduced in Liguria region where it is propagated by cuttings. In 2006, severe virus-like diseases consisting of: leaf mosaic, narrowing of the lamina, yellow spots, vein yellowing, white necrotic spots, rings and line-patterns on oldest leaves and variegation on the younger ones, were observed on plot plants growing in different ornamental nurseries in Imperia province. No flower symptoms were observed. Since in 2002 Polygala has been indicated in Italy as a new natural host of Cucumber mosaic virus (CMV), preliminary PAS-ELISA tests were carried out to verify this virus presence. CMV alone was detected associated to chlorotic mosaic symptoms. In plants showing yellow veins and spots, potyvirus-like filamentous particles were observed at electron microscope. In IME (“decoration”) and PAS-ELISA tests, this virus appeared partially serologically related to Soybean mosaic virus and strongly to Bean yellow mosaic virus. P. myrtifolia showing rings and line-patterns was positive (in PAS-ELISA) to Batavian lettuce strain of Tomato spotted wilt virus (TSWV: PVAS-450; American Type Culture Collection, Manassas, VA, USA).) RT-PCR technique was employed using specific primers for 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 of 823 bp. Considering that in 1940 wild Polygala in South Africa has been indicated as a probably host for Tospoviruses (unconfirmed report), our study establishes P. myrtifolia as a new natural host for TSWV.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
