Kiwifruit Vine Decline Syndrome (KVDS) has become a major concern in Italy, impacting both plant health and production. This study aims to investigate how KVDS affects soil health indicators and the composition of soil microbial communities by comparing symptomatic and asymptomatic areas in two kiwifruit orchards located in Latium, Italy. Soil samples were collected during both spring and autumn to assess seasonal variations in soil physicochemical properties, enzyme activities, and microbial biomass. The results reveal that KVDS influences several soil properties, including pH, electrical conductivity, and the contents of water-soluble carbon and nitrogen. However, these effects varied between orchards and across different seasons. Additionally, KVDS significantly impacts soil enzyme activities and microbial biomass, as assessed through the phospholipid fatty acid (PLFA) analysis, particularly showing an increase in fungal biomass in symptomatic areas. Metabarcoding further demonstrates that microbial communities differ between symptomatic and asymptomatic soils, exhibiting notable shifts in both diversity and relative abundance. Our findings emphasise the complex interactions between plants, soil, and microbial communities in relation to KVDS. This suggests that the syndrome is multifactorial and likely linked to an imbalance in soil microbial communities at the rhizosphere level, which can negatively affect soil health.

The rapid expansion of pomegranate (Punica granatum L.) cultivation in central and southern Italy has revealed emerging phytosanitary challenges, including “pomegranate wood decay syndrome”, characterised by cortical cankers, wood browning, and progressive plant decline. This study investigates the fungal microbiota associated with symptomatic pomegranate wood using a combined approach of traditional fungal isolation and ITS2 metabarcoding analysis. Samples from two orchards in Lazio were examined, revealing a complex fungal community with a high prevalence of Neofusicoccum parvum (putative) and species belonging to the genus Diaporthe. Pathogenicity tests confirmed the role of N. parvum in causing significant wood browning, while other isolates showed variable virulence. Statistical analyses validated the pathogenicity of select isolates, with the putative Diaporthe eres (Nitschke) consistently demonstrating potential pathogenic activity across all trials. Metabarcoding identified 289 taxa, highlighting a richer fungal diversity in the symptomatic wood compared to the asymptomatic sections. Notably, Coniella granati, previously implicated in pomegranate decline, was absent in the studied orchards. The findings reveal that pomegranate wood decay is a complex syndrome driven by fungal pathogens and environmental stressors, such as low temperatures. This study highlights the value of integrative approaches for understanding and managing fungal-associated wood diseases in pomegranate orchards.

Kiwifruit Vine Decline Syndrome (KVDS) has recently become a concern in Italy, impacting plant health and production. This study aims to investigate the influence of KVDS on soil health indi-cators and the composition of soil microbial communities by comparing symptomatic and asymptomatic kiwifruit orchards located in two areas in Latium, Italy. Soil samples were collected in spring and autumn to evaluate the seasonal variations in soil physicochemical properties, enzyme activities, and microbial biomass. The results revealed that KVDS impacted soil properties such as pH, electrical conductivity, and water-soluble carbon and nitrogen contents, though these effects varied by orchard and season. Moreover, KVDS significantly affected soil enzyme activities and microbial biomass assessed through PLFAs analysis, particularly showing an increase in fungal biomass in symptomatic areas. In addition, metabarcoding revealed differences in the microbial communities between symptomatic and asymptomatic soils, with notable shifts in their diversity and relative abundance. Our findings highlight the complex interactions between plant-soil-microbiome in KVDS, suggesting that KVDS is multifactorial and is likely associated with an imbalance of soil microbial communities at the rhizosphere level, which can negatively affect soil health.

The rapid expansion of pomegranate (Punica granatum L.) cultivation in central and southern Italy has revealed emerging phytosanitary challenges, including "pomegranate wood decay syndrome”, characterised by cortical cankers, wood browning, and progressive plant decline. This study investigates the fungal microbiota associated with symptomatic pomegranate wood using a combined approach of traditional fungal isolation and ITS2 metabarcoding analysis. Samples from two orchards in Lazio were examined, revealing a complex fungal community with a high prevalence of Neofusicoccum parvum and species of the Diaporthe complex. Pathogenicity tests confirmed the role of N. parvum in causing significant wood browning, while other isolates showed variable virulence. Statistical analyses validated the pathogenicity of select isolates, with Diaporthe eres (Nitschke) consistently demonstrating potential pathogenic activity across all trials. Metabarcoding identified 289 taxa highlighting a richer fungal diversity in symptomatic wood compared to asymptomatic sections. Notably, Coniella granati, previously implicated in pomegranate decline, was absent in the studied orchards. The findings reveal that pomegranate wood decay is a complex syndrome driven by fungal pathogens and environmental stressors, such as low temperatures. This study highlights the value of integrative approaches for understanding and managing fungal-associated wood diseases in pomegranate orchards.

Kiwifruit (Actinidia deliciosa) represents a crop of high economic importance, with Italy ranking as the third-largest global producer. In recent years, Italian kiwifruit orchards have been severely affected by Kiwifruit Vine Decline Syndrome (KVDS), a disease characterised by root rot, leaf chlorosis, phylloptosis, and progressive vine decline. To investigate the potential involvement of soilborne oomycetes in KVDS, a survey of symptomatic plants was conducted in the Latina province (Lazio, Italy). Two oomycete species, Pythium dissotocum and Globisporangium sylvaticum, were consistently isolated from diseased roots. Pathogenicity tests on A. deliciosa cv. ‘Hayward’ revealed that both species induced severe symptoms under waterlogged conditions, whereas only mild or no symptoms developed under regular irrigation. These results provide the first evidence that P. dissotocum and G. sylvaticum can contribute to KVDS symptomatology in Italy. These findings offer new insight into KVDS dynamics, highlighting the variability of pathogenic species involved. Similar oomycetes with comparable pathogenic traits have been previously reported, reinforcing the multifactorial nature of the disease and the influence of environmental stress, particularly waterlogging, on its expression.