Neofusicoccum mediterraneum Is Involved in a Twig and Branch Dieback of Olive Trees Observed in Salento (Apulia, Italy)

Olive trees are infected and damaged by Botryosphaeriaceae fungi in various countries. The botryosphaeriaceous fungus Neofusicoccum mediterraneum is highly aggressive and is a major concern for olive groves in Spain and California (USA), where it causes ‘branch and twig dieback’ characterized by wood discoloration, bark canker, and canopy blight. During surveys of olive groves in Apulia (southern Italy), we noticed that—in some areas—trees were heavily affected by severe branch and twig dieback. In addition, chlorosis and the appearance of red-bronze patches on the leaf preceded the wilting of the foliage, with necrotic leaves persisting on the twigs. Given the severity of the manifestation in zones also subject to olive quick decline syndrome (OQDS) caused by Xylella fastidiosa subsp. pauca, we investigated the etiology and provide indications for differentiating the symptoms from OQDS. Isolation from diseased wood samples revealed a mycete, which was morphologically and molecularly identified as N. mediterraneum. The pathogenicity tests clearly showed that this fungus is able to cause the natural symptoms. Therefore, also considering the low number of tested samples, N. mediterraneum is a potential causal agent of the observed disease. Specifically, inoculation of the twigs caused complete wilting in two to three weeks, while inoculation at the base of the stem caused severe girdling wedge-shaped cankers. The growth rate of the fungus in in vitro tests was progressively higher from 10 to 30 °C, failing to grow at higher temperatures, but keeping its viability even after prolonged exposure at 50 °C. The capacity of the isolate to produce catenulate chlamydospores, which is novel for the species, highlights the possibility of a new morphological strain within N. mediterraneum. Further investigations are ongoing to verify whether additional fungal species are involved in this symptomatology.

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Identification of Fungal Species Associated with Branch Dieback of Olive and Resistance of Table Cultivars to Neofusicoccum mediterraneum and Botryosphaeria dothidea

Plant Disease ◽

10.1094/pdis-06-16-0806-re ◽

2017 ◽

Vol 101 (2) ◽

pp. 306-316 ◽

Cited By ~ 17

Author(s):

Juan Moral ◽

Carlos Agustí-Brisach ◽

Mario Pérez-Rodríguez ◽

Carlos Xaviér ◽

M. Carmen Raya ◽

...

Keyword(s):

Dna Analysis ◽

Large Subunit ◽

Fungal Species ◽

Control Measures ◽

Nuclear Ribosomal Dna ◽

Botryosphaeria Dothidea ◽

Immature Fruit ◽

Pathogenicity Tests ◽

Olive Trees ◽

Branch Dieback

Over two consecutive seasons, 16 olive orchards with trees exhibiting dieback symptoms on branches were surveyed in southern Spain. The six dominant fungal species recovered were characterized by means of phenotypic observations, DNA analysis (by sequencing of the internal transcribed spacer, β-tubulin, and large subunit nuclear ribosomal DNA regions), and pathogenicity tests. Additionally, three isolates collected from Tunisian olive trees showing similar dieback symptoms, one isolate of Colletotrichum godetiae, and a reference isolates of Neofusicoccum mediterraneum were included. The resistance of the 11 most important table cultivars to N. mediterraneum and Botryosphaeria dothidea, the causal agent of “escudete” (small shield) of fruit, was studied by the inoculation of branches and immature fruit, respectively. The species Cytospora pruinosa, N. mediterraneum, Nothophoma quercina, Comoclathris incompta, and Diaporthe sp. were identified. Only N. mediterraneum and C. incompta were able to induce the typical dieback symptoms and cankers that affected the development of the plants. The species N. mediterraneum was the most virulent among the evaluated species, although differences in virulence among its isolates were observed. The remaining fungal species were weakly pathogenic to nonpathogenic on plants. According to resistance tests, ‘Gordal Sevillana’ and ‘Manzanilla Cacereña’ were the most susceptible to branch dieback caused by N. mediterraneum. Furthermore, the fruit of ‘Aloreña de Atarfe’ and ‘Manzanilla de Sevilla’ were the most susceptible to B. dothidea. Knowledge of the etiology and cultivar resistance of these diseases will help to establish better control measures.

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Further In Vitro Assessment and Mid-Term Evaluation of Control Strategy of Xylella fastidiosa subsp. pauca in Olive Groves of Salento (Apulia, Italy)

Pathogens ◽

10.3390/pathogens10010085 ◽

2021 ◽

Vol 10 (1) ◽

pp. 85

Author(s):

Giuseppe Tatulli ◽

Vanessa Modesti ◽

Nicoletta Pucci ◽

Valeria Scala ◽

Alessia L’Aurora ◽

...

Keyword(s):

Control Strategy ◽

Xylella Fastidiosa ◽

In Planta ◽

Bacterial Concentration ◽

Infected Area ◽

Olive Groves ◽

Term Evaluation ◽

In Vitro Assessment ◽

Olive Trees

During recent years; Xylella fastidiosa subsp. pauca (Xfp) has spread in Salento causing relevant damage to the olive groves. Measures to contain the spreading of the pathogen include the monitoring of the areas bordering the so-called “infected” zone and the tree eradication in case of positive detection. In order to provide a control strategy aimed to maintain the tree productivity in the infected areas, we further evaluated the in vitro and in planta mid-term effectiveness of a zinc-copper-citric acid biocomplex. The compound showed an in vitro bactericidal activity and inhibited the biofilm formation in representative strains of X. fastidiosa subspecies, including Xfp isolated in Apulia from olive trees. The field mid-term evaluation of the control strategy assessed by quantitative real-time PCR in 41 trees of two olive groves of the “infected” area revealed a low concentration of Xfp over the seasons upon the regular spraying of the biocomplex over 3 or 4 consecutive years. In particular, the bacterial concentration lowered in July and October with respect to March, after six consecutive treatments. The trend was not affected by the cultivar and it was similar either in the Xfp-sensitive cultivars Ogliarola salentina and Cellina di Nardò or in the Xfp-resistant Leccino. Moreover, the scoring of the number of wilted twigs over the seasons confirmed the trend. The efficacy of the treatment in the management of olive groves subjected to a high pathogen pressure is highlighted by the yielded a good oil production

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Chemical Composition and Antifungal Activity of Essential Oils from Flowers, Leaves, Rhizomes, and Bulbs of the Wild Iraqi Kurdish Plant Iris Persica

Natural Product Communications ◽

10.1177/1934578x1701200334 ◽

2017 ◽

Vol 12 (3) ◽

pp. 1934578X1701200 ◽

Cited By ~ 1

Author(s):

Hawraz Ibrahim M. Amin ◽

Ahmed Anwar Amin ◽

Solveig Tosi ◽

Giorgio Giacomo Mellerio ◽

Faiq H. S. Hussain ◽

...

Keyword(s):

Antifungal Activity ◽

Essential Oils ◽

Antimicrobial Agents ◽

Trichophyton Mentagrophytes ◽

Fungal Species ◽

Volatile Fraction ◽

In Vitro Tests ◽

Microsporum Canis ◽

Main Component

Essential oils obtained by hydrodistillation of different parts of Iris persica L. were investigated for the first time by GC-FID and GC-MS; moreover, their antifungal activities were determined. 34, 32, 27, and 17 compounds were identified in the oils from air-dried flowers, leaves, rhizomes and fresh bulbs, respectively, representing ≥ 98% each oil. The major constituents of the flower essential oil were phenylethanol (24.8%) and furfural (13.8%), which, as the main component, constituted also 39.0% and 22.2% of the leaf and rhizome volatile fractions, respectively. Phenylacetaldehyde (37.1%) was the main constituent of the bulb volatile fraction. In in vitro tests, moderate antifungal activity was detected for the oils against strains of the human pathogenic fungal species Candida albicans, Microsporum canis, and Trichophyton mentagrophytes, the plant-fungal pathogen Pyricularia oryzae, and the fungal food contaminant Aspergillus carbonarius,. The highest activity was exhibited by the essential oils from leaves and flowers, suggesting that they could be considered natural antimicrobial agents.

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Identification and Pathogenicity of Fungal Species Associated with Canker Diseases of Pistachio in California

Plant Disease ◽

10.1094/pdis-10-18-1717-re ◽

2019 ◽

Vol 103 (9) ◽

pp. 2397-2411 ◽

Cited By ~ 6

Author(s):

Mohamed T. Nouri ◽

Daniel P. Lawrence ◽

Leslie A. Holland ◽

David A. Doll ◽

Craig E. Kallsen ◽

...

Keyword(s):

Phylogenetic Analyses ◽

Schizophyllum Commune ◽

Elongation Factor ◽

Fungal Species ◽

Elongation Factor 1Α ◽

Translation Elongation ◽

Brown Discoloration ◽

Pathogenicity Tests ◽

Branch Dieback ◽

Translation Elongation Factor 1Α

A survey was conducted during 2015 and 2016 in pistachio orchards throughout the San Joaquin Valley of California to investigate the occurrence of canker diseases and identify the pathogens involved. Cankers and dieback symptoms were observed mainly in orchards aged >15 years. Symptoms of canker diseases included brown to dark brown discoloration of vascular tissues, wood necrosis, and branch dieback. In total, 58 fungal isolates were obtained from cankers and identified based on multilocus phylogenetic analyses (internal transcribed spacer, glyceraldehyde 3-phosphate dehydrogenase, β-tubulin, calmodulin, actin 1, and translation elongation factor 1α) representing 11 fungal species: Colletotrichum karstii, Cytospora californica, Cytospora joaquinensis, Cytospora parapistaciae, Cytospora pistaciae, Diaporthe ambigua, Didymella glomerata, Diplodia mutila, Neofusicoccum mediterraneum, Phaeoacremonium canadense, and Schizophyllum commune. Pathogenicity tests conducted in the main pistachio cultivars Kerman, Golden Hills, and Lost Hills using the mycelium-plug method indicated that all fungal species were pathogenic to Pistacia vera. All species tested caused cankers in pistachio branches, although virulence among species varied from high to moderate. Overall, N. mediterraneum and Cytospora spp. were the most widespread and virulent species associated with canker diseases of pistachio in California.

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On the Applicability of Chitosan Oligomers-Amino Acid Conjugate Complexes as Eco-Friendly Fungicides against Grapevine Trunk Pathogens

Agronomy ◽

10.3390/agronomy11020324 ◽

2021 ◽

Vol 11 (2) ◽

pp. 324

Author(s):

Laura Buzón-Durán ◽

Natalia Langa-Lomba ◽

Vicente González-García ◽

José Casanova-Gascón ◽

Jesús Martín-Gil ◽

...

Keyword(s):

Amino Acid ◽

Wood Decay ◽

Field Trials ◽

Fungal Species ◽

In Vitro Tests ◽

In Planta ◽

Management Culture ◽

Amino Acid Conjugate ◽

Acid Conjugate

In a context in which the incidence and severity of grapevine fungal diseases is increasing as a result of both climate change and modern management culture practices, reducing the excessive use of phytosanitary products in viticulture represents a major challenge. Specifically, grapevine trunk diseases (GTDs), caused by several complexes of wood decay or xylem-inhabiting fungi, pose a major challenge to vineyard sustainability. In this study, the efficacy of chitosan oligomers (COS)–amino acid conjugate complexes against three fungal species belonging to the Botryosphaeriaceae family (Neofusicoccum parvum, Diplodia seriata, and Botryosphaeria dothidea) was investigated both in vitro and in planta. In vitro tests led to EC50 and EC90 effective concentrations in the 254.6−448.5 and 672.1−1498.5 µg·mL−1 range, respectively, depending on the amino acid involved in the conjugate complex (viz. cysteine, glycine, proline or tyrosine) and on the pathogen assayed. A synergistic effect between COS and the amino acids was observed against D. seriata and B. dothidea (synergy factors of up to 2.5 and 2.8, respectively, according to Wadley’s method). The formulations based on COS and on the conjugate complex that showed the best inhibition rates, COS−tyrosine, were further investigated in a greenhouse trial on grafted vines of two varieties (”Tempranillo” on 775P and “Garnacha” on 110R rootstock), artificially inoculated with the mentioned three Botryosphaeriaceae species. The in planta bioassay revealed that the chosen formulations induced a significant decrease in disease severity against N. parvum and B. dothidea. In summary, the reported conjugate complexes may be promising enough to be worthy of additional examination in larger field trials.

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Fungi pathogenic to the corm of arracacha (Arracada xanthorrhiza) in Puerto Rico

The Journal of Agriculture of the University of Puerto Rico ◽

10.46429/jaupr.v84i1-2.3901 ◽

1969 ◽

Vol 84 (1-2) ◽

pp. 53-64

Author(s):

Evelyn Rosa-Márquez ◽

Lydia I. Rivera ◽

Carlos E. Ortiz ◽

Arcángel Rodríguez

Keyword(s):

Puerto Rico ◽

Phytophthora Palmivora ◽

In Vitro Tests ◽

Fusarium Spp ◽

Thiophanate Methyl ◽

Pathogenicity Tests

Phytophthora palmivora, Rhizoctonia sp. and two isolates of Fusarium spp. were identified and associated with the arracacha (Arracada xanthorrhiza) corm rot in pathogenicity tests conducted in vitro and in vivo. In vitro tests revealed that these fungi were pathogenic to the corm. Fungi caused lesions to the corm under greenhouse conditions. Three major symptoms were observed: necrotized roots; necrotized roots with a dry, brown, hard injury to the internal corm tissue; and wet lesions with brown shades. The highest incidence of affected corms occurred with P. palmivora in combination with Rhizoctonia sp., and the lowest was observed in corms inoculated with Rhizoctonia sp. alone. The most severe symptoms were caused by P. palmivora alone and in combination with Rhizoctonia sp. In vitro tests were conducted to evaluate the efficacy of metalaxyl, etridiazofe thiophanate-methyl, and fosetyl-al against the isolated fungi at doses of 5 to 200 mg ai/kg. Among the fungicides tested, etridiazole thiophanate-methyl was effective against all fungi associated with corm rot. Micelial growth of P. palmivora was completely inhibited with metataxyl at all doses and by etridiazole thiophanate-methyl with doses of 20 or more mg ai/kg.

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Rice Blast in Puerto Rico

The Journal of Agriculture of the University of Puerto Rico ◽

10.46429/jaupr.v62i3.10367 ◽

1969 ◽

Vol 62 (3) ◽

pp. 290-300

Author(s):

Lii-Jang Liu

Keyword(s):

Puerto Rico ◽

Rice Straw ◽

Rice Blast ◽

Mycelial Growth ◽

Potato Dextrose Agar ◽

Pyricularia Oryzae ◽

In Vitro Tests ◽

Optimum Temperature ◽

Pathogenicity Tests

Rice blast, which had not been observed during the last six decades in Puerto Rico, reappeared recently in Manatí and in the Gurabo Substation, affecting Brazos, a cultivar introduced from Texas. Pathogenicity tests, as well as studies on the conidial morphology, showed that the fungus isolated from typical blast lesions is Pyricularia oryzae Cav. The physiology of the fungus and its sporulation on various media also were studied. The optimum temperature range, both for mycelial growth and for germination of conidia, was found to be between 24 to 28° C. Sporulation occurred satisfactorily on potato-dextrose agar enriched with coconut milk, and on steamed corn and barley, and rice-straw-decoction agars. In vitro tests with fungicides benomyl, pentachloronitrobenzene, mancozeb, chloroneb, and captan indicated that the first two compounds are the most effective in inhibiting mycelial growth of P. oryzae.

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Effect of the mycoflora of ergot (Claviceps purpurea)sclerotia on their viability

Plant Protection Science ◽

10.17221/48/2009-pps ◽

2010 ◽

Vol 46 (No. 2) ◽

pp. 66-71 ◽

Cited By ~ 2

Author(s):

M. Ondřej ◽

B. Cagaš ◽

E. Ondráčková

Keyword(s):

Trichoderma Harzianum ◽

Fungal Species ◽

In Vitro Tests ◽

Conidial Suspension ◽

Claviceps Purpurea ◽

Clonostachys Rosea ◽

Trichoderma Hamatum ◽

Total Destruction ◽

One Year

Twenty fungal species were isolated from sclerotia of ergot (Claviceps purpurea) originating from rye. In in vitro tests with the anamorphic stage of ergot (known as Sphacelia segetum) high mycoparasitic activity was exhibited only by two of them – Clonostachys rosea and Trichoderma harzianum, moderate mycoparasitic activity was detected in Ulocladium sp., Clonostachys catenulata, Trichoderma hamatum, and Trichothecium roseum. In in vitro tests of mycoparasitic activity with sclerotia of the fungus Sclerotinia sclerotiorum their rapid and total destruction was brought about only by the fungi Clonostachys rosea and Trichoderma harzianum. The viability of overwintering ergot sclerotia in the soil was influenced by their placement, age, depth of placement and treatment with a conidial suspension of the fungus Clonostachys rosea. The highest viability values were reported in fresh one-year-old sclerotia. In two-year-old sclerotia their viability was reduced and their sensitivity to microbial activity was higher. The sclerotia aged 3 years or more did not germinate and were all microbiologically degraded in the soil. More than 80% of degradation of sclerotia which were 1 to 2 years old was caused by the fungus Clonostachys rosea. The degradation of sclerotia aged 3 to 4 years was brought about by bacteria, soil edafauna (mites, nematodes) and fungi of the genera Trichoderma, Fusarium, Clonostachys, etc.

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Toxicity, Pathogenicity, and Genetic Differentiation of Five Species of Fusarium from Sorghum and Millet

Phytopathology ◽

10.1094/phyto-95-0275 ◽

2005 ◽

Vol 95 (3) ◽

pp. 275-283 ◽

Cited By ~ 73

Author(s):

John F. Leslie ◽

Kurt A. Zeller ◽

Sandra C. Lamprecht ◽

John P. Rheeder ◽

Walter F. O. Marasas

Keyword(s):

Fusarium Species ◽

Toxin Production ◽

Fungal Species ◽

Banding Patterns ◽

Length Polymorphisms ◽

Amplified Fragment Length Polymorphisms ◽

Pathogenicity Tests ◽

Plant Pathogenicity ◽

Sorghum Seedling

Fusarium isolates recovered from sorghum and millet are commonly identified as F. moniliforme, but with the recognition of new species in this group, the strains given this name are being re-evaluated. We analyzed five strains each from five Fusarium species (F. andiyazi, F. nygamai, F. pseudonygamai, F. thapsinum, and F. verticillioides) often associated with sorghum and millet for their ability to produce fumonisin and moniliformin, their toxicity to ducklings, and their ability to cause disease on sorghum seedlings in vitro. These species can be distinguished with isozymes (fumarase, NADP-dependent isocitrate dehydrogenase, and malate dehydrogenase) and with banding patterns resulting from amplified fragment length polymorphisms. Two species, F. pseudonygamai and F. thapsinum, produced high levels of moniliformin, but little or no fumonisins, and were consistently highly toxigenic in the duckling tests. Two species, F. verticillioides and F. nygamai, produced high levels of fumonisins, but little or no moniliformin, and also were toxigenic in the duckling tests. F. andiyazi produced little or no toxin and was the least toxigenic in the duckling tests. In sorghum seedling pathogenicity tests, F. thapsinum was the most virulent followed by F. andiyazi, then F. verticillioides, and finally F. nygamai and F. pseudonygamai, which were similar to each other. Thus, these five species, which would once have all been called F. moniliforme, differ sufficiently in terms of plant pathogenicity and toxin production profile, that their previous misidentification could explain inconsistencies in the literature and differences observed by researchers who thought they were all working with the same fungal species.

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Anti-Diabetic Activity of a Mineraloid Isolate, in vitro and in Genetically Diabetic Mice

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831/a000048 ◽

2011 ◽

Vol 81 (1) ◽

pp. 34-42 ◽

Cited By ~ 1

Author(s):

Joel Deneau ◽

Taufeeq Ahmed ◽

Roger Blotsky ◽

Krzysztof Bojanowski

Keyword(s):

Dna Microarrays ◽

Human Fibroblasts ◽

Diabetic Animal ◽

In Vitro Tests ◽

Diabetic Mice ◽

Fossil Material ◽

Expression Of Genes ◽

Enhanced Expression ◽

Genetically Diabetic Mice

Type II diabetes is a metabolic disease mediated through multiple molecular pathways. Here, we report anti-diabetic effect of a standardized isolate from a fossil material - a mineraloid leonardite - in in vitro tests and in genetically diabetic mice. The mineraloid isolate stimulated mitochondrial metabolism in human fibroblasts and this stimulation correlated with enhanced expression of genes coding for mitochondrial proteins such as ATP synthases and ribosomal protein precursors, as measured by DNA microarrays. In the diabetic animal model, consumption of the Totala isolate resulted in decreased weight gain, blood glucose, and glycated hemoglobin. To our best knowledge, this is the first description ever of a fossil material having anti-diabetic activity in pre-clinical models.

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