Symptoms of severe decline of fig (Ficus carica) have been recently detected in Salento area of the Apulia region (southeastern Italy). Symptoms begin with leaf chlorosis and evolve into necroses, twig defoliation and death of lateral branches. Cankers are often observed, associated with extensive wood discolouration under the dead bark and together with bark beetle galleries. In September 2021, wood sections and adult insect specimens were collected from symptomatic trees in several orchards. Bark beetles were morphologically and molecularly identified as Cryphalus dilutus (Curculionidae, Scolytinae). Fungal isolations were performed on PDA amended with 0.5 g L-1 streptomycin sulfate, from 200 wood fragments and 52 C. dilutus adults. Three groups of potential pathogens were recovered from the plant tissues and insects, including Botryosphaeriaceae (38.5%), Fusarium solani species complex FSSC (36.9%), and Ophiostomatoid fungi (6.7%). Mixed infections with at least two pathogens were common (67%). A set of 47 single spore isolates were identified using multilocus phylogenetic analyses based on the sequences of three informative genes. Preliminary results showed that almost 50% of the FSSC isolates belong to the newly described species Neocosmospora perseae causing trunk cankers on avocado in Sicily. At least three species of Botryosphaeriaceae (Neofusicoccum parvum, Lasiodiplodia theobromae, Botryosphaeria dothidea) and two genera of Ophiostomatoid fungi (Graphium and Ceratocystis) were also identified. Phylogenetic analyses and pathogenicity tests are ongoing to determine the role of each fungus in the aetiology of the observed decline syndrome, and verify the potential role of the C. dilutus as a pathogen vector.
A new disease complex threatening fig (Ficus carica L.) in Southern Italy
Cavalieri V;
2022
Abstract
Symptoms of severe decline of fig (Ficus carica) have been recently detected in Salento area of the Apulia region (southeastern Italy). Symptoms begin with leaf chlorosis and evolve into necroses, twig defoliation and death of lateral branches. Cankers are often observed, associated with extensive wood discolouration under the dead bark and together with bark beetle galleries. In September 2021, wood sections and adult insect specimens were collected from symptomatic trees in several orchards. Bark beetles were morphologically and molecularly identified as Cryphalus dilutus (Curculionidae, Scolytinae). Fungal isolations were performed on PDA amended with 0.5 g L-1 streptomycin sulfate, from 200 wood fragments and 52 C. dilutus adults. Three groups of potential pathogens were recovered from the plant tissues and insects, including Botryosphaeriaceae (38.5%), Fusarium solani species complex FSSC (36.9%), and Ophiostomatoid fungi (6.7%). Mixed infections with at least two pathogens were common (67%). A set of 47 single spore isolates were identified using multilocus phylogenetic analyses based on the sequences of three informative genes. Preliminary results showed that almost 50% of the FSSC isolates belong to the newly described species Neocosmospora perseae causing trunk cankers on avocado in Sicily. At least three species of Botryosphaeriaceae (Neofusicoccum parvum, Lasiodiplodia theobromae, Botryosphaeria dothidea) and two genera of Ophiostomatoid fungi (Graphium and Ceratocystis) were also identified. Phylogenetic analyses and pathogenicity tests are ongoing to determine the role of each fungus in the aetiology of the observed decline syndrome, and verify the potential role of the C. dilutus as a pathogen vector.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
