Blackberry Samples Research Articles

Mould and yeast flora in fresh berries, grapes and citrus fruits

Fresh fruits are prone to fungal contamination in the field, during harvest, transport, marketing, and with the consumer. It is important to identify fungal contaminants in fresh fruits because some moulds can grow and produce mycotoxins on these commodities while certain yeasts and moulds can cause infections or allergies. In this study, 251 fresh fruit samples including several varieties of grapes, strawberries, blueberries, raspberries, blackberries, and various citrus fruits were surface-disinfected, incubated at room temperature for up to 14 days without supplemental media, and subsequently examined for mould and yeast growth. The level of contamination (percent of contaminated items/sample) varied depending on the type of fruit. All raspberry and blackberry samples were contaminated at levels ranging from 33% to 100%, whereas 95% of the blueberry samples supported mould growth at levels between 10% and 100% of the tested berries, and 97% of strawberry samples showed fungal growth on 33–100% of tested berries. The most common moulds isolated from these commodities were Botrytis cinerea, Rhizopus (in strawberries), Alternaria, Penicillium, Cladosporium and Fusarium followed by yeasts, Trichoderma and Aureobasidium. Thirty-five percent of the grape samples tested were contaminated and supported fungal growth; the levels of contamination ranged from 9% to 80%. The most common fungi spoiling grapes were Alternaria, B. cinerea and Cladosporium. Eighty-three percent of the citrus fruit samples showed fungal growth at levels ranging from 25% to 100% of tested fruits. The most common fungi in citrus fruits were Alternaria, Cladosporium, Penicillium, Fusarium and yeasts. Less common were Trichoderma, Geotrichum and Rhizopus.

Perspectives in neuro-ophthalmology.

<h3>Abstract</h3> Grapevine red blotch disease (GRBD) is an emerging disease caused by grapevine red blotch virus (GRBV). It is widespread in a majority of wine grape production regions in the United States and differential spread dynamics have been reported between the regions. In this study, we surveyed eight vineyard sites in southern Oregon over four years for the progression of GRBD incidence. The surveyed vineyards included five sites that were five years or older and three sites that were three years old. The disease incidence in the older blocks ranged from 2.81 to 58.78%; whereas in the younger blocks it ranged from 0.29 to 1.11%. Some of these vineyards implemented frequent disease scouting, removing, and replanting. The disease incidence in these blocks remained less than 5% over the survey period. However, in the vineyards that did not implement any roguing and replanting, the disease incidence increased by nearly 30-fold after three years. We analyzed the spatial distribution of the disease in vineyards surveyed in 2020 and found that the disease distribution is highly aggregated based on Spatial Analysis by Distance Indices (SADIE). In a separate study, we also tested the GRBV infection status of asymptomatic vines next to symptomatic vines to aid in the decision making process when roguing and replanting. Out of 410 asymptomatic vines, surrounding 41 symptomatic vines, only two tested positive for GRBV. Additionally, in 2020 and 2021, we tested the GRBV status on previously identified possible alternative host species, blackberries (<i>Rubus armeniacus</i>) and wild/feral grapes (<i>Vitis riparia</i>) collected from areas surrounding the four survey sites. We observed that GRBV was present in 10 to 70% of the wild grape samples in both years and 10% of the blackberry samples in 2020. However, the virus titer was low in blackberry samples and it was not detected in 2021 samples. These results indicate the potential importance of wild grapes as alternative hosts on GRBD incidence and spread in southern Oregon vineyards, while blackberry is unlikely to be an alternative host with epidemiological significance.