A predictive model based on a pluviothermic index for leathery pocket and fruitlet core rot of pineapple cv. ‘Queen’

European Journal of Plant Pathology - Leathery pocket (LP) and fruitlet core rot (FCR) of pineapple (Ananas comosus L.) caused by Penicillium funiculosum Thom. and/or Fusarium moniliforme Sheld...     

Pathogenicity of Phytophthora multivora to Eucalyptus gomphocephala and Eucalyptus marginata

Phytophthora multivora is associated with the rhizosphere of declining Eucalyptus gomphocephala, Eucalyptus marginata and Agonis flexuosa. Two pathogenicity experiments were conducted. The first experiment examined the pathogenicity of five P. multivora isolates and one Phytophthora cinnamomi isolate on the root systems of E. gomphocephala and one P. multivora isolate on the root system of E. marginata. In the second experiment, the pathogenicity of P. multivora to E. gomphocephala and E. marginata saplings was measured using under‐bark stem inoculation. In Experiment 1, the P. cinnamomi isolate was more aggressive than all P. multivora isolates causing significant loss of fine roots and plant death. Two P. multivora isolates and the P. cinnamomi isolate caused significant losses of E. gomphocephala fine roots 0–2 mm in diameter and significantly reduced the surface area of roots 0–1 mm in diameter. One P. multivora and the P. cinnamomi isolate significantly reduced the surface area of roots 1–2 mm in diameter. Two of the P. multivora isolates significantly reduced the number of E. gomphocephala root tips. In E. marginata, the length and surface area of roots 0–1 mm in diameter and number of root tips were significantly reduced by P. multivora infestation. Rhizosphere infestation with the P. multivora isolates and P. cinnamomi isolate on E. gomphocephala, and one P. multivora isolate on E. marginata, did not significantly influence the foliar nutrient concentrations. In Experiment 2, under‐bark inoculation with P. multivora caused significant lesion extension in E. gomphocephala and E. marginata saplings, compared to the control. We propose that P. multivora is inciting E. gomphocephala and E. marginata decline by causing fine root loss and subsequently interfering with nutrient cycling throughout the plant. The impact of fine root loss on the physiology of plants in sites infested with P. multivora requires further research.     

Cold plasma: a potential new method to manage postharvest diseases caused by fungal plant pathogens

Development of alternative, chemical‐free approaches for control of postharvest fungi on a commercial scale has become a challenge for plant pathologists in recent years. Although there are several established techniques such as heat that are used as postharvest treatments, they often have disadvantages, including alteration of food quality due to physiological responses to the treatment, or environmental pollution. A promising new postharvest treatment is cold plasma, which is a gas‐derived mix of atoms, excited molecules and charged particles. Cold plasma has no known adverse effects on fresh produce or the environment. It is an established technology in the medical field and has been demonstrated to successfully control bacterial pathogens that cause food safety issues. This review focuses on the potential of cold plasma technology for postharvest disease control, especially those caused by fungi. An overview of plasma generation systems is provided, and in vivo and in vitro research is reviewed to consider benefits, limitations and research gaps in the context of cold plasma as a potential method for controlling postharvest fungal pathogens. Finally, recommendations are provided for the application of this technology in commercial facilities.     

Thoracic vertebral osteochondroma in a cat

A thoracic vertebral (T5) osteochondroma was discovered in a 1 1/2-year-old male blue Persian cat with a history of acute hind limb paresis. Myelography revealed a mass on the dorsal surface of the vertebral body, which resulted in dorsal compression of the spinal cord. A dorsal laminectomy was performed, and the mass was rongeured entirely from the vertebral body. Although the cat's progress was initially slow after surgery, its neurologic status was assessed to be near normal, 15 months later.     

Evaluation of an indirect enzyme-linked immunosorbent assay for the detection of feline lentivirus-reactive antibodies in wild felids,employing a puma lentivirus-derived synthetic peptide antigen

An enzyme-linked immunosorbent assay (ELISA) using a puma lentivirus-derived synthetic peptide as coating antigen was evaluated as a diagnostic test for infection with feline immunodeficiency virus (FIV) or related lentiviruses in free-ranging lions. The sensitivity and specificity of the ELISA was determined using two approaches. In the first approach, the results were standardized according to certain statistical criteria, and in the second, the puma lentivirus western blot was used as the gold standard. The sensitivity of the test when compared with the standardized results was 85.4% and the specificity 100%. The sensitivity of the test when using the western blot as the gold standard was 78.6% and the specificity 100%. The test would therefore be well-suited to the screening of populations of wild felids in which FIV or related lentiviruses are endemic. The results also indicate that in spite of genetic divergence between lentiviruses isolated from Panthera and Felis spp., puma lentivirus-derived antigens can be used in immunoassays for the detection of antibodies in Panthera spp. reactive to FIV or related lentiviruses. The results also indicate that the lion population in the Hluhluwe-Umfolozi Game Reserve, South Africa is lentivirus negative.