Stunting of Gladiolus flower spike associated with Tobacco streak virus (TSV)

• Published in: Phytopathologia mediterranea Vol. 26; no. 2; pp. 73 - 80
• Main Authors: Bellardi, M.G., Vicchi, V., Gelli, C.
• Format: Journal Article
• Language: English
• Published: Bologna Unione Fitopatologica Mediterranea 01-08-1987; Mediterranean Phytopathological Union
• Subjects: Biological and medical sciences; Flowers; Fundamental and applied biological sciences. Psychology; Gladiolus; Ilarvirus; Infections; Leaves; Lesions; Necrosis; Pathology. Damages, economic importance; Phytopathology. Animal pests. Plant and forest protection; Plant viruses and viroids; Plants; Quinoa; Symptoms; tobacco streak virus; Viruses; Iridaceae; Monocotyledones; Europe; Ornamental crop; Gladiolus; Virus; Sicily; Transmission electron microscopy; Angiospermae; Italy; Flower crop; Spermatophyta; Emilia-Romagna; Ilarvirus; Tobacco streak virus
• ISSN: 0031-9465; 1593-2095

Two Tobacco streak virus (TSV) isolates from imported Gladiolus (Gladiolus sp.) 'Peter Pears' were biologically and serologically compared. The first isolate: TSV-1, was found in Emilia-Romagna (Northern Italy), the second one: TSV-2, in Sicily. All the gladiolus plants infected by TSV-1 and TSV-2 showed shorter flower spikes (mosaic, ringspots and necrotic streaks were sometimes present on the leaves of stunted plants). In rate-zonal density gradient centrifugation both of them sedimented as three components: Top (non infectious), Middle and Bottom (infectious by themselves); they were also serologically indistinguishable (no spurs in cross-reaction tests) and appeared identical in the electron microscope (size between 25 and 30 nm). The two TSV isolates differed in host range, in the symptoms of infected plants and in some properties in crude sap. In fact, TSV-1 infected 17 of 22 species tested and TSV-2 only 11; TSV-1 usually induced only local symptoms, whereas TSV-2 primary lesions followed by systemic invasion; in crude sap TSV-2 was less stable than TSV-1. This is the first report of «stunting of spike flower» associated with TSV in Gladiolus. Due isola ti del virus della necrosi perinervale del Tabacco (TSV), provenienti da Gladiolo (Gladiolus sp.) cv. Peter Pears importata, sono stati biologicamente e sierologicamente confrontati tra loro. Il primo isolato: TSV-1, è stato rinvenuto in Emilia-Romagna, il secondo: TSV-2, in Sicilia. Tutti i gladioli infetti con TSV-1 e TSV-2 erano caratterizzati da un vistoso nanismo della spiga fiorale; le foglie mostravano a volte sintomi di mosaico, piccoli anelli cloro-necrotici e striature necrotiche. Purificati in gradienti di saccarosio, i due isolati erano costituiti di tre componenti: Top (non infettivo), Middle e Bottom (infettivi); essi apparivano inoltre identici sierologicamente (nessuno sperone nelle reazioni incrociate in agar) come anche al microscopio elettronico (diametro fra 25 e 30 nm). I due isolati di TSV differivano invece nella gamma di piante ospiti, nella sintomatologia da queste evidenziata e su alcune proprietà nel sueco crudo. Infatti TSV-1 infettava 17 di 22 specie inoculate, mentre TSV-2 solo 11; TSV-1 generalmente determina va sintomi locali, mentre TSV-2 sia locali che sistemici; nel sueco crudo TSV-1 si mostrava piu stabile di TSV-2. È questa la prima segnalazione di «nanismo della spiga fiorale» associato alia presenza di TSV nel Gladiolo.