Occurrence and diversity of black-foot pathogens on asymptomatic nursery-produced grapevines in Turkiye

Abstract

Black-foot (BF) disease of grapevines in nurseries and young vineyards is caused by soilborne Cylindrocarpon-like asexual morphs. They can be found both in symptomatic and asymptomatic vines, being spread to new grape growing areas during vineyard establishment. In this study, 42 grapevine nurseries located in different geographical regions in Turkiye were surveyed in 2021 to determine the presence of BF pathogens on asymptomatic marketable plants.Black-foot fungi were isolated from the roots or basal ends of asymptomatic dormant vines in 39 of them (92.9%). The percentage of isolation of BF pathogens ranged from 1.4 to 51.4% (average 18.4%). Seven species: Cylindrodendrum alicantinum, Cylindrocladiella peruviana, Dactylonectria macrodidyma, D. novozelandica, D. torresensis, Ilyonectria liriodendri, and I.2 robusta were identified based on DNA sequencing of histone H3 gene and phylogenetic analyses, D. torresensis being the most frequent. From these species Ca. peruviana, D. novozelandica and I. robusta were detected for the first time on grapevines in Turkiye. Pathogenicity tests on 1103P rootstock cuttings revealed that all species significantly decreased root biomass and increased root disease severity index, when compared with the non-inoculated control, D. novozelandica being the most virulent. Pathogenicity of Cm. alicantinum to grapevine was confirmed for the first time, thus this species should be included as causal agent of BF of grapevines. These findings point out that BF pathogens are highly prevalent in asymptomatic nursery produced grapevines and could represent a serious threat for Turkish viticulture.

Current status of grapevine trunk disease pathogens on asymptomatic nursery-produced grapevines in Türkiye

“…Th e results showed that dieback (in 30% of surveyed nurseries) and Petri disease pathogens (33% of nurseries) were moderately prevalent. Previously, black foot pathogens were found to be very common in most of surveyed nurseries (Akgül et al, 2022). Nine of 43 nurseries producing non-graft ed Sultana Seedless grapevines were examined in this survey, and dieback and Petri disease pathogens were identi- fied only in three nurseries, from asymptomatic plants.…”

“…Akgül and Ahioğlu (2019) screened GTD pathogens associated with young grapevine decline in 1-3-year-old vineyards in Southern Türkiye. A survey 3 years later revealed occurrence and diversity of black foot pathogens in nurseries (Akgül et al, 2022). However, no substantial information is available on the current status of other GTD pathogens in marketable dormant plants in Turkish grapevine nurseries.…”

Fungal trunk diseases of fruit trees in Europe: pathogens, spread and future directions

“…(Gramaje et al, 2011a) and Pleurostoma richardsiae (Halleen et al, 2007b). Up to 29 species of Cylindrocarpon-like asexual morphs belonging of Campylocarpon, Cylindrocladiella, Cylindrodendrum, Dactylonectria, Ilyonectria, Neonectria, Pleiocarpon and Thelonectria genera have been associated with black-foot of grapevine (Gramaje et al, 2018;Aigoun-Mouhous et al, 2019;Akgül et al, 2022). Dactylonectria torresensis is the most common species associated with this disease in Europe (Reis et al, 2013, Carlucci et al, 2017 and Algeria (Aigoun-Mouhous et al, 2019), while Da.…”

Black foot in nursery grapevines in Uruguay caused by Dactylonectria and Ilyonectria

“…Currently, more than 30 fungal species of Campylocarpon, Cylindrocladiella, Dactylonectria, Ilyonectria, Neonectria, Pleiocarpon, and Thelonectria, commonly known as Cylindrocarpon-like asexual morphs, are associated with black foot (Agustí-Brisach and Armengol, 2013;Lombard et al, 2014;Carlucci et al, 2017;Aigoun-Mouhous et al, 2019). Among these, D. torresensis has been reported as the prevalent species in several countries (Reis et al, 2013;Berlanas et al, 2017;Carlucci et al, 2017;Aigoun-Mouhous et al, 2019;Akgül et al, 2022).…”

“…Black foot pathogens have been frequently isolated from nursery grapevine plants, indicating that these plants play important roles in the spread of this disease (Halleen et al, 2006a;Abreo et al, 2010;Agustí-Brisach et al, 2013;Cardoso et al, 2013;Carlucci et al, 2017;Pintos et al, 2018;Aigoun-Mouhous et al, 2019;Berlanas et al, 2020;Akgül et al, 2022). Several studies have focused on determining when infection occurs during propagation processes, and there is consensus that the nursery rooting phase is where black foot pathogen infections increase significantly (Halleen et al, 2003;Agustí-Brisach et al, 2013;Carbone et al, 2022).…”