Milkwort (Polygala myrtifolia L.) is an attractive ornamental perennial shrub with rich purple flowers and increasing commercial importance in temperate climatic areas. In Southern Italy the use of this plant in open gardens is concentrated in warm regions, whereas in other less temperate regions (Central and North Italy) milkwort is kept as a potted plant. On milkwort very few pathogens have been described, except for Cylindrocladium pauciramosum (mainly in Italy and Spain) and Cucumber mosaic virus in Italy. Recently, several cases of milkwort plant decline were recovered in various ornamental nurseries of Southern Italy. Affected plants appeared from partially to completely wilted, stunted and weakly chlorotic. In symptomatic plants Fusarium sp. colonies were consistently isolated from crown, basal stem, and root lesions. Fusarium isolates associated with milkwort wilt were primarily identified at genera level by morphological observation of macroconidia, microconidia and culture characteristic whereas at the level of species, the isolated fusaria were identified by performing Polymerase Chain Reaction (PCR) of their ribosomal DNA, using the universal Internal Transcribed Spacer (ITS) primers. Species-level identification was further refined through BLASTn searches of ITS sequence data in GenBank (NCBI) at http://blast.ncbi.nlm.nih.gov/. The most frequent and representative fungal isolates were identified as Fusarium oxysporum and F. solani. The etiology of this possible new milkwort disease was proved by fulfilling Koch’s postulates on artificially inoculated milkwort healthy plants. This is the first record of milkwort wilt caused by pathogenic Fusarium species.
FUSARIUM OXYSPORUM AND F. SOLANI: TWO NOVEL FUNGAL PATHOGENS CAUSING DECLINE OF MILKWORT (POLYGALA MYRTIFOLIA L.) PLANTS IN SOUTHERN ITALY
DE CURTIS, Filippo;Palmieri, D.;LIMA, Giuseppe
2014-01-01
Abstract
Milkwort (Polygala myrtifolia L.) is an attractive ornamental perennial shrub with rich purple flowers and increasing commercial importance in temperate climatic areas. In Southern Italy the use of this plant in open gardens is concentrated in warm regions, whereas in other less temperate regions (Central and North Italy) milkwort is kept as a potted plant. On milkwort very few pathogens have been described, except for Cylindrocladium pauciramosum (mainly in Italy and Spain) and Cucumber mosaic virus in Italy. Recently, several cases of milkwort plant decline were recovered in various ornamental nurseries of Southern Italy. Affected plants appeared from partially to completely wilted, stunted and weakly chlorotic. In symptomatic plants Fusarium sp. colonies were consistently isolated from crown, basal stem, and root lesions. Fusarium isolates associated with milkwort wilt were primarily identified at genera level by morphological observation of macroconidia, microconidia and culture characteristic whereas at the level of species, the isolated fusaria were identified by performing Polymerase Chain Reaction (PCR) of their ribosomal DNA, using the universal Internal Transcribed Spacer (ITS) primers. Species-level identification was further refined through BLASTn searches of ITS sequence data in GenBank (NCBI) at http://blast.ncbi.nlm.nih.gov/. The most frequent and representative fungal isolates were identified as Fusarium oxysporum and F. solani. The etiology of this possible new milkwort disease was proved by fulfilling Koch’s postulates on artificially inoculated milkwort healthy plants. This is the first record of milkwort wilt caused by pathogenic Fusarium species.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
