Search Results (4)

Avocado, a fruit consumed worldwide and essential for countries like Mexico and Chile, faces significant postharvest challenges, particularly during prolonged storage and transportation periods, where Botryosphaeriaceae and Glomerellaceae genera cause fruit rots that can generate substantial economic losses. This study investigated three Hass avocado orchards in the Valparaíso region of Chile to identify spore dispersion peaks, analyze the aerial dynamics of fungal inoculum, and evaluate the association with climatic conditions, as well as the incidence (I) and damage index (DI) of fruit rots. Spore traps were installed in symptomatic trees and monitored weekly over 13 months. Meteorological data were collected in parallel. Fruits from these orchards were sampled to evaluate postharvest rots, physiological maturity, and disease severity using molecular techniques, including DNA sequencing and phylogenetic analysis of isolated pathogens. The results revealed that spore peaks for both fungal families were closely associated with increased rainfall and high relative humidity, particularly from June to mid-September (winter season). The Santo Domingo orchard exhibited the highest disease pressure, with stem-end rot reaching an I of 44% and a DI of 17.25%, and anthracnose reaching an I of 23% and a DI of 12.25%. This study provides the first long-term, field-based evidence of airborne spore dynamics of Botryosphaeriaceae and Glomerellaceae in Chilean avocado orchards and their statistical relationship with environmental variables. These findings highlight the potential of incorporating climatic indicators—such as rainfall thresholds and humidity levels—into monitoring and early-warning systems to optimize fungicide application timing, reduce unnecessary chemical use, and improve postharvest disease management in avocado production. Full article

This study aimed to provide foundational research for the biological control of postharvest avocado fruits anthracnose and establish a microbial system of postharvest avocado fruits. The high-throughput sequencing of avocado fruits from the anthracnose-infected and healthy groups was performed using Illumina NovaSeq second-generation sequencing technology. The results revealed that, except for Colletotrichum sp. strain 38#, there were differences in the bacterial community structure of avocados before and after infection, as determined through alpha and beta diversity analysis. Additionally, there were significant differences in the endophytic fungal community structure, allowing clear differentiation between the infected and healthy avocados. The endophytic bacterial community was primarily composed of 4 phyla and 10 genera, with the Bacteroidota phylum and Chryseobacterium genus demonstrating sensitivity to anthracnose pathogens, as evidenced by a decrease in their relative abundance after infection. The endophytic fungal community was characterized by 3 phyla and 10 genera. After infection, the relative abundance of 2 phyla (Anthophyta and Basidiomycota) and 7 genera (Eucalyptus, Candida, Kluyveromyces, Talaromyces, Oidiodendron, Nigrospora, and Pestalotiopsis) decreased, whereas the relative abundance of the Colletotrichum genus increased dramatically. The LEfSe (Linear discriminant analysis Effect Size) analysis indicated that significant biomarkers were more prevalent in endophytic bacteria than in endophytic fungi in the avocados. In endophytic bacteria, the key biomarkers included the Firmicutes phylum (Bacilli class), Proteobacteria phylum (Gammaproteobacteria class, Pseudomonadales order, Pseudomonadaceae family, and Pseudomonas genus), Flavobacteriales order, Weeksellaceae family, and Chryseobacterium genus. In endophytic fungi, the important biomarkers were Saccharomycetes class (Saccharomycetales order), Glomerellales order (Glomerellaceae family and Colletotrichum genus), and Botryosphaeriales order (Botryosphaeriaceae family and Lasiodiplodia genus). These results may provide a theoretical basis for the development of future biological agents for avocado anthracnose. Full article

Colletotrichum, a genus within the phylum Ascomycota (Fungi) and family Glomerellaceae are important plant pathogens globally. In this paper, we detail four Colletotrichum species found in mangrove ecosystems. Two new species, Colletotrichum rhizophorae and C. thailandica, and a new host record for Colletotrichum fructicola were identified in Thailand. Colletotrichum tropicale was collected from Taiwan’s mangroves and is a new record for Rhizophora mucronata. These identifications were established through a combination of molecular analysis and morphological characteristics. This expanded dataset for Colletotrichum enhances our understanding of the genetic diversity within this genus and its associations with mangrove ecosystems. The findings outlined herein provide data on our exploration of mangrove pathogens in Asia. Full article

This study endeavored to sustainably control aphids and anthracnose after spraying endophytic Isaria javanica pf185 under field conditions. Under two different tents; one batch of seedlings was sprayed with a 10⁷ conidia/mL I. javanica pf185 suspension; while another was sprayed with 0.05% Tween 80^® in distilled water. Six leaf discs from the top; middle; and bottom part of the plant canopy were weekly collected and placed on moistened filter paper in a Petri dish for insecticidal and antifungal bioassays against Myzus persicae and Colletotrichum acutatum. Differences were noticed from the 18th day after spraying with mortality (86.67 ± 0.57% versus 36.67 ± 0.64%) and leaf damage (13.45 ± 0.03% versus 41.18 ± 0.06%) on fungus-treated and controlled, respectively. The corrected insecticidal efficacy was 20.43, 39.82, 72.32, 66.43 and 70.04%, while the corrected fungicidal efficacy was 26.07, 38.01, 53.35, 29.08 and 41.81% during five successive weeks. A positive correlation was evident between insecticidal efficacy and relative humidity (r² = 0.620) and temperature (r² = 0.424), respectively. No correlation was found between antifungal activity and relative humidity (r² = 0.061) and temperature (r² = 0), respectively. The entomopathogenic fungus survived on leaf surface area and in tissues after spraying. Full article