Morphology Characterization, Molecular Phylogeny, and Pathogenicity of Diaporthe passifloricola on Citrus reticulata cv. Nanfengmiju in Jiangxi Province, China

The Nanfengmiju (Citrus reticulata cv. Nanfengmiju), a high-quality local variety of mandarin, is one of the major fruit crops in Jiangxi Province, China. Citrus melanose and stem-end rot, two common fungal diseases of Nanfengmiju, are both caused by Diaporthe spp. (syn. Phomopsis spp.). Identification of the Diaporthe species is essential for epidemiological studies, quarantine measures, and management of diseases caused by these fungi. Melanose disease was observed on Nanfengmiju fruit in Jiangxi Province of China in 2016. Based on morphological characterization and multi-locus phylogenetic analyses, three out of 39 isolates from diseased samples were identified as D. passifloricola. Since these three isolates did not cause melanose on citrus fruit in the pathogenicity tests, they were presumed to be endophytic fungi present in the diseased tissues. However, our results indicate that D. passifloricola may persist as a symptom-less endophyte in the peel of citrus fruit, yet it may cause stem-end if it invades the stem end during fruit storage. To the best of our knowledge, this is the first report of D. passifloricola as the causal agent of the stem-end rot disease in Citrusreticulata cv. Nanfengmiju.

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Identification of Lasiodiplodia pseudotheobromae Causing Fruit Rot of Citrus in China

Plants ◽

10.3390/plants10020202 ◽

2021 ◽

Vol 10 (2) ◽

pp. 202

Author(s):

Jianghua Chen ◽

Zihang Zhu ◽

Yanping Fu ◽

Jiasen Cheng ◽

Jiatao Xie ◽

...

Keyword(s):

Phylogenetic Analyses ◽

Elongation Factor ◽

Morphological Characteristics ◽

Citrus Fruit ◽

Economic Loss ◽

Fruit Rot ◽

Post Inoculation ◽

Citrus Reticulata ◽

Postharvest Diseases ◽

Citrus Reticulata Blanco

Considering the huge economic loss caused by postharvest diseases, the identification and prevention of citrus postharvest diseases is vital to the citrus industry. In 2018, 16 decayed citrus fruit from four citrus varieties—Satsuma mandarin (Citrus unshiu), Ponkan (Citrus reticulata Blanco cv. Ponkan), Nanfeng mandarin (Citrus reticulata cv. nanfengmiju), and Sugar orange (Citrus reticulata Blanco)—showing soft rot and sogginess on their surfaces and covered with white mycelia were collected from storage rooms in seven provinces. The pathogens were isolated and the pathogenicity of the isolates was tested. The fungal strains were identified as Lasiodiplodia pseudotheobromae based on their morphological characteristics and phylogenetic analyses using the internal transcribed spacer regions (ITS), translation elongation factor 1-α gene (TEF), and beta-tubulin (TUB) gene sequences. The strains could infect wounded citrus fruit and cause decay within two days post inoculation, but could not infect unwounded fruit. To our knowledge, this is the first report of citrus fruit decay caused by L. pseudotheobromae in China.

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Biological and Molecular Characterization of Four Botryosphaeria Species Isolated from Pear Plants Showing Stem Wart and Stem Canker in China

Plant Disease ◽

10.1094/pdis-10-13-1060-re ◽

2014 ◽

Vol 98 (6) ◽

pp. 716-726 ◽

Cited By ~ 24

Author(s):

Lifeng Zhai ◽

Meixin Zhang ◽

Gang Lv ◽

Xiaoren Chen ◽

Nana Jia ◽

...

Keyword(s):

Molecular Characterization ◽

Phylogenetic Analyses ◽

Stem Canker ◽

Morphological Characterization ◽

The Other ◽

Internal Transcribed Spacer Region ◽

Pathogenicity Tests ◽

The Common ◽

Stem Cankers

Pear stem wart and pear stem canker, which have been considered as two different fungal diseases caused by pathogens belonging to Botryosphaeria spp., commonly occur and cause serious damage in the main pear-producing areas in China. To identify the species of this genus infecting pear in China, 131 Botryosphaeria isolates were recovered from pear samples exhibiting symptoms collected from 20 different provinces and areas. Morphological characterization and phylogenetic analyses of the ribosomal DNA internal transcribed spacer region and the β-tubulin and EF1-α genes revealed that Botryosphaeria dothidea, B. rhodina, B. obtusa, and B. parva were associated with different pear stem wart and stem canker symptoms. Remarkably, all isolates of B. dothidea were obtained from the samples showing either stem wart or stem canker lesions; however, the isolates of the other three species were obtained only from the samples showing stem canker. Pathogenicity tests on the pear shoots showed that B. dothidea isolates could induce stem wart or stem canker lesions but all the isolates of the other three species could only induce stem cankers. However, the isolates of B. parva, B. rhodina, and B. obtusa exhibited higher virulence than that of the B. dothidea isolates on the pear fruit. Our results suggest that B. dothidea is the common causal agent for these two diseases (a pear stem wart and a pear-related stem canker), whereas B. parva, B. rhodina, and B. obtusa only cause pear stem canker diseases. To our knowledge, this study represents the first report for biological and molecular characterization of four Botryosphaeria spp. isolated from pear plants showing stem wart and stem canker in China.

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Etiology of Botryosphaeria Panicle and Shoot Blight of Pistachio (Pistacia vera) caused by Botryosphaeriaceae in Italy

Plant Disease ◽

10.1094/pdis-08-21-1672-re ◽

2021 ◽

Author(s):

Giorgio Gusella ◽

Daniel P. Lawrence ◽

Dalia Aiello ◽

Yong Luo ◽

Giancarlo Polizzi ◽

...

Keyword(s):

Complex Disease ◽

Phylogenetic Analyses ◽

Morphological Characterization ◽

Fungal Species ◽

Lesion Length ◽

Pistacia Vera ◽

Mycelial Plug ◽

Shoot Blight ◽

Pathogenicity Tests ◽

A Minor

Pistachio (Pistacia vera) is an important crop in Italy, traditionally cultivated in Sicily (southern Italy) for several decades now. In recent years, new orchards have been planted in new areas of the island. Field surveys conducted in 2019 revealed the presence of symptomatic trees showing shoot dieback, cankers, fruit spots, and leaf lesions. Isolations from symptomatic samples consistently yielded fungal species in the Botryosphaeriaceae family. Identification of collected isolates was conducted using morphological and molecular analyses. Morphological characterization was based on conidia measurements of representative isolates and also effects of temperatures on mycelial growth was evaluated. DNA data derived from sequencing the ITS, tef1-α and tub2 gene regions were analyzed via phylogenetic analyses (Maximum Parsimony and Maximum Likelihood). Results of the analyses confirmed the identity of Botryosphaeria dothidea, Neofusicoccum hellenicum and Neofusicoccum mediterraneum. Pathogenicity tests were conducted on detached twigs and in the fields both on shoots as well as on fruit clusters using the mycelial plug technique. The inoculation experiments revealed that among the Botryosphaeriaceae species identified in this study N. hellenicum (occasionally detected) and N. mediterraneum were the most aggressive based on lesion length on shoots and fruits. N. mediterraneum was the most widespread among the orchards while B. dothidea can be considered a minor pathogen involved in this complex disease of pistachio. Moreover, to our knowledge, this is the first report of N. hellenicum in Italy.

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First Report of Alternaria Brown Spot of Citrus Caused by Alternaria alternata in Peru

Plant Disease ◽

10.1094/pd-90-0686c ◽

2006 ◽

Vol 90 (5) ◽

pp. 686-686 ◽

Cited By ~ 5

Author(s):

J. E. Marín ◽

H. S. Fernández ◽

N. A. Peres ◽

M. Andrew ◽

T. L. Peever ◽

...

Keyword(s):

Alternaria Alternata ◽

Sequence Similarity ◽

Phylogenetic Analyses ◽

Morphological Characterization ◽

Brown Spot ◽

Limiting Factor ◽

Citrus Diseases ◽

Alternaria Brown Spot ◽

Young Leaves ◽

Pathogenicity Tests

Alternaria brown spot, caused by Alternaria alternata (Fr.) Keissler, causes leaf, twig, and fruit lesions and reduces yield and fruit quality of many tangerines (Citrus reticulata Blanco) and their hybrids (3). In 2003, characteristic symptoms of brown spot were observed on young leaves and fruit of ‘Minneola’ tangelo in the Satipo Province of Peru. In 2004, the disease was discovered in the provinces of Chanchamayo, Leoncio Prado, and La Convención in the Junin, Huanuco, and Cusco regions, respectively, as well as in the Apurimac and the Ene valleys. In 2005, it was confirmed in the province of Oxapampa in the Pasco Region. Brown-to-black lesions surrounded by yellow halos and veinal necrosis were observed on young leaves, often causing abscission of young shoots and twig dieback. Light brown, circular lesions were observed on fruit, and when severe, resulted in premature abscission. Isolations from infected leaves and twigs were made on potato dextrose agar (PDA) with 10 μg/ml of benomyl. Colonies that developed after 5 days at 27°C were olive brown-to-black and produced small, muriform, pigmented conidia typical of A. alternata. On PDA without benomyl, gray colonies with conidia typical of Colletotrichum gloeosporioides were recovered frequently. Inoculation of three detached young shoots of ‘Minneola’ by spraying with a suspension of 105 conidia/ml of A. alternata produced leaf and twig symptoms characteristic of the disease after 48 h and confirmed pathogenicity of three isolates. Symptoms were not observed on control leaves sprayed with water nor on an equal number of leaves inoculated with a suspension of 105 conidia/ml of C. gloeosporioides. Reisolation of A. alternata from diseased tissue fulfilled Koch's postulates. DNA was extracted from 17 isolates and a partial endopolygalacturonase gene was amplified and sequenced (2). Sequences of all 17 isolates were identical, and in BLAST searches of the NCBI database, the closest matches were A. alternata accession nos. AY295023.1, AY295022.1, and AY295021.1 with 100, 99.8, and 99.8% sequence similarity, respectively. Phylogenetic analyses revealed that all isolates from Peru clustered with brown spot isolates from Israel, Turkey, South Africa, and Australia (1). These results, along with morphological characterization and pathogenicity tests, confirm the identity of the fungus as the tangerine pathotype of A. alternata. The disease has significantly reduced yield and the commercial value of fruit and may be a limiting factor for the production of susceptible cultivars in those areas of Peru. References: (1) T. L. Peever et al. Phytopathology 92:794, 2002. (2) T. L. Peever et al. Mycologia 96:119, 2004, (3) L.W. Timmer et al. Pages 19–21 in: Compendium of Citrus Diseases. 2nd ed. L. W. Timmer et al eds. The American Phytopathological Society, St. Paul, MN, 2000.

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Antidiabetic Properties of Naringenin: A Citrus Fruit Polyphenol

Biomolecules ◽

10.3390/biom9030099 ◽

2019 ◽

Vol 9 (3) ◽

pp. 99 ◽

Cited By ~ 16

Author(s):

Danja J. Den Hartogh ◽

Evangelia Tsiani

Keyword(s):

Insulin Resistance ◽

Animal Studies ◽

Citrus Fruit ◽

Epidemiological Studies ◽

Personal Health ◽

Current Review ◽

Vegetables And Fruits

Type 2 diabetes mellitus (T2DM) is a metabolic disease characterized by insulin resistance and hyperglycemia and is associated with personal health and global economic burdens. Current strategies/approaches of insulin resistance and T2DM prevention and treatment are lacking in efficacy resulting in the need for new preventative and targeted therapies. In recent years, epidemiological studies have suggested that diets rich in vegetables and fruits are associated with health benefits including protection against insulin resistance and T2DM. Naringenin, a citrus flavanone, has been reported to have antioxidant, anti-inflammatory, hepatoprotective, nephroprotective, immunomodulatory and antidiabetic properties. The current review summarizes the existing in vitro and in vivo animal studies examining the anti-diabetic effects of naringenin.

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Outbreak of Leaf Spot and Fruit Rot in Florida Strawberry Caused by Neopestalotiopsis spp.

Plant Disease ◽

10.1094/pdis-06-20-1290-re ◽

2021 ◽

pp. PDIS-06-20-1290

Author(s):

Juliana S. Baggio ◽

Bruna B. Forcelini ◽

Nan-Yi Wang ◽

Rafaela G. Ruschel ◽

James C. Mertely ◽

...

Keyword(s):

Internal Transcribed Spacer ◽

Phylogenetic Analyses ◽

Morphological Characteristics ◽

Taxonomic Status ◽

Spore Production ◽

Potato Dextrose Agar ◽

Fruit Rot ◽

Low Genetic Diversity ◽

Pathogenicity Tests ◽

A New Species

Pestalotiopsis-like species have been reported affecting strawberry worldwide. Recently, severe and unprecedented outbreaks have been reported in Florida commercial fields where leaf, fruit, petiole, crown, and root symptoms were observed, and yield was severely affected. The taxonomic status of the fungus is confusing because it has gone through multiple reclassifications over the years. Morphological characteristics, phylogenetic analyses, and pathogenicity tests were evaluated for strawberry isolates recovered from diseased plants in Florida. Phylogenetic analyses derived from the combined internal transcribed spacer, β-tub, and tef1 regions demonstrated that although there was low genetic diversity among the strawberry isolates, there was a clear separation of the isolates in two groups. The first group included isolates recovered over a period of several years, which was identified as Neopestalotiopsis rosae. Most isolates recovered during the recent outbreaks were genetically different and may belong to a new species. On potato dextrose agar, both groups produced white, circular, and cottony colonies. From the bottom, colonies were white to pale yellow for Neopestalotiopsis sp. and pale luteous to orange for N. rosae. Spores for both groups were five-celled with three median versicolored cells. Mycelial growth and spore production were higher for the new Neopestalotiopsis sp. isolates. Isolates from both groups were pathogenic to strawberry roots and crowns. However, the new Neopestalotiopsis sp. proved more aggressive in fruit and leaf inoculation tests, confirming observations from the recent outbreaks in commercial strawberry fields in Florida.

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Characterization and Phylogeny of Fungi from Industrial Wastewater Using Highly Conserved Multiple Gene Loci

10.21203/rs.3.rs-289731/v1 ◽

2021 ◽

Author(s):

Blessing Amaka Ezeonuegbu ◽

Dauda Abdullahi Machido ◽

Clement Z. Whong ◽

Wisdom S. Japhet ◽

Clement Ameh Yaro ◽

...

Keyword(s):

Phylogenetic Trees ◽

Phylogenetic Analyses ◽

Large Subunit ◽

Industrial Effluent ◽

Pcr Amplification ◽

Morphological Characterization ◽

Likelihood Method ◽

Internal Transcribed Spacer Region ◽

Fungal Isolates ◽

Fungal Dna Extraction

Abstract The aim of this study was isolation and molecular characterization of fungi from untreated industrial effluent by multigene phylogenetic analyses. The Fungi isolated were characterized based on PCR amplification and genomic sequencing of the internal transcribed spacer region (ITS), partial β-tubulin (Ben A), calmodulin (CaM), and DNA-directed RNA polymerase second large subunit (RPB2) genes, along with morphological characterization and species diversity. Fungal DNA extraction kits and primers sets for the selected genes were purchased and used following the manufacturer’s instructions. The obtained sequences were subjected to BLAST analysis and the corresponding fungal isolates were assigned species names after comparison with representative sequences available in GenBank. All the sequences from this study were deposited in GenBank and the accession number assigned. Phylogenetic trees of the fungal isolates were drawn for each gene by the Maximum Likelihood method using MEGA 7.0 software. Fifteen (15) Fungi species belonging to four genera of Aspergillus, Penicillium, Fusarium and Trichoderma with Aspergillus as the predominant genus were identified.

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Beneficial Regulatory Effects of Polymethoxyflavone—Rich Fraction from Ougan (Citrus reticulata cv. Suavissima) Fruit on Gut Microbiota and Identification of Its Intestinal Metabolites in Mice

Antioxidants ◽

10.3390/antiox9090831 ◽

2020 ◽

Vol 9 (9) ◽

pp. 831

Author(s):

Jiebiao Chen ◽

Yue Wang ◽

Tailin Zhu ◽

Sijia Yang ◽

Jinping Cao ◽

...

Keyword(s):

Gut Microbiota ◽

High Performance ◽

Citrus Fruit ◽

Intestinal Content ◽

Citrus Reticulata ◽

Citrus Fruits ◽

Human Gut ◽

16S Ribosomal Dna ◽

Regulatory Effects ◽

Main Components

Polymethoxyflavones (PMFs) are special flavonoids in citrus fruits that have been suggested to be beneficial to human health. However, whether PMFs in citrus fruit alter human gut microbiota is not well understood. The aim of the present study was to investigate the effects of PMF-rich fraction from Ougan (Citrus reticulata cv. Suavissima) on gut microbiota and evaluate the intestinal metabolic profile of PMFs in Institute of Cancer Research mice. The main components of the PMF-rich fraction were nobiletin, tangeretin, and 5-demethylnobiletin. The composition of the gut microbiota was analyzed using 16S ribosomal DNA sequencing. The results showed that after oral administration, the composition of mice gut microbiota was significantly altered. The relative abundance of two probiotics, Lactobacillus and Bifidobacterium, were found to increase significantly. A total of 21 metabolites of PMFs were detected in mice intestinal content by high performance liquid chromatography electrospray ionization tandem mass spectrometry, and they were generated through demethylation, demethoxylation, hydroxylation, and glucuronidation. Our results provided evidence that PMFs have potential beneficial regulatory effects on gut microbiota that in turn metabolize PMFs, which warrants further investigation in human clinical trials.

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Phylogenetic Analysis of Downy Mildew Pathogens of Opium Poppy and PCR-Based In Planta and Seed Detection of Peronospora arborescens

Phytopathology ◽

10.1094/phyto-97-11-1380 ◽

2007 ◽

Vol 97 (11) ◽

pp. 1380-1390 ◽

Cited By ~ 42

Author(s):

Blanca B. Landa ◽

Miguel Montes-Borrego ◽

Francisco J. Muñoz-Ledesma ◽

Rafael M. Jiménez-Díaz

Keyword(s):

Downy Mildew ◽

Field Experiments ◽

Phylogenetic Analyses ◽

Its Region ◽

Epidemiological Studies ◽

Papaver Somniferum ◽

Opium Poppy ◽

Recent Common Ancestor ◽

In Planta ◽

Commercial Seed

Severe downy mildew diseases of opium poppy (Papaver somniferum) can be caused by Peronospora arborescens and P. cristata, but differentiating between the two pathogens is difficult because they share morphological features and a similar host range. In Spain, where severe epidemics of downy mildew of opium poppy have occurred recently, the pathogen was identified as P. arborescens on the basis of morphological traits. In this current study, sequence homology and phylogenetic analyses of the internal transcribed spacer regions (ITS) of the ribosomal DNA (rDNA) were carried out with DNA from P. arborescens and P. cristata from diverse geographic origins, which suggested that only P. arborescens occurs in cultivated Papaver somniferum in Spain. Moreover, analyses of the rDNA ITS region from 27 samples of downy-mildew-affected tissues from all opium-poppy-growing regions in Spain showed that genetic diversity exists within P. arborescens populations in Spain and that these are phylogenetically distinct from P. cristata. P. cristata instead shares a more recent, common ancestor with a range of Peronospora species that includes those found on host plants that are not members of the Papaveraceae. Species-specific primers and a PCR assay protocol were developed that differentiated P. arborescens and P. cristata and proved useful for the detection of P. arborescens in symptomatic and asymptomatic opium poppy plant parts. Use of these primers demonstrated that P. arborescens can be transmitted in seeds and that commercial seed stocks collected from crops with high incidence of the disease were frequently infected. Field experiments conducted in microplots free from P. arborescens using seed stocks harvested from infected capsules further demonstrated that transmission from seedborne P. arborescens to opium poppy plants can occur. Therefore, the specific-PCR detection protocol developed in this study can be of use for epidemiological studies and diagnosing the pathogen in commercial seed stocks; thus facilitating the sanitary control of the disease and avoidance of the pathogen distribution in seeds.

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Colletotrichum species associated with anthracnose of Pyrus spp. in China

Persoonia - Molecular Phylogeny and Evolution of Fungi ◽

10.3767/persoonia.2019.42.01 ◽

2019 ◽

Vol 42 (1) ◽

pp. 1-35 ◽

Cited By ~ 21

Author(s):

M. Fu ◽

P.W. Crous ◽

Q. Bai ◽

P.F. Zhang ◽

J. Xiang ◽

...

Keyword(s):

Plant Pathogens ◽

Novel Species ◽

Phylogenetic Analyses ◽

Koch’S Postulates ◽

Colletotrichum Species ◽

Organ Specific ◽

Pathogenicity Tests ◽

Koch's Postulates

Colletotrichum species are plant pathogens, saprobes, and endophytes on a range of economically important hosts. However, the species occurring on pear remain largely unresolved. To determine the morphology, phylogeny and biology of Colletotrichum species associated with Pyrus plants, a total of 295 samples were collected from cultivated pear species (including P. pyrifolia, P. bretschneideri, and P. communis) from seven major pear-cultivation provinces in China. The pear leaves and fruits affected by anthracnose were sampled and subjected to fungus isolation, resulting in a total of 488 Colletotrichum isolates. Phylogenetic analyses based on six loci (ACT, TUB2, CAL, CHS-1, GAPDH, and ITS) coupled with morphology of 90 representative isolates revealed that they belong to 10 known Colletotrichum species, including C. aenigma, C. citricola, C. conoides, C. fioriniae, C. fructicola, C. gloeosporioides, C. karstii, C. plurivorum, C. siamense, C. wuxiense, and two novel species, described here as C. jinshuiense and C. pyrifoliae. Of these, C. fructicola was the most dominant, occurring on P. pyrifolia and P. bretschneideri in all surveyed provinces except in Shandong, where C. siamense was dominant. In contrast, only C. siamense and C. fioriniae were isolated from P. communis, with the former being dominant. In order to prove Koch's postulates, pathogenicity tests on pear leaves and fruits revealed a broad diversity in pathogenicity and aggressiveness among the species and isolates, of which C. citricola, C. jinshuiense, C. pyrifoliae, and C. conoides appeared to be organ-specific on either leaves or fruits. This study also represents the first reports of C. citricola, C. conoides, C. karstii, C. plurivorum, C. siamense, and C. wuxiense causing anthracnose on pear.

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