-
Persoonia 2019The species complex (FIESC) is shown to encompass 33 phylogenetic species, across a wide range of habitats/hosts around the world. Here, 77 pathogenic and endophytic...
The species complex (FIESC) is shown to encompass 33 phylogenetic species, across a wide range of habitats/hosts around the world. Here, 77 pathogenic and endophytic FIESC strains collected from China were studied to investigate the phylogenetic relationships within FIESC, based on a polyphasic approach combining morphological characters, multi-locus phylogeny and distribution patterns. The importance of standardised cultural methods to the identification and classification of taxa in the FIESC is highlighted. Morphological features of macroconidia, including the shape, size and septum number, were considered as diagnostic characters within the FIESC. A multi-locus dataset encompassing the 5.8S nuclear ribosomal gene with the two flanking internal transcribed spacers (ITS), translation elongation factor (), calmodulin (), partial RNA polymerase largest subunit () and partial RNA polymerase second largest subunit (), was generated to distinguish species within the FIESC. Nine novel species were identified and described. The locus is demonstrated to be a primary barcode with high success rate in amplification, and to have the best species delimitation compared to the other four tested loci.
PubMed: 32214498
DOI: 10.3767/persoonia.2019.43.03 -
Plant Disease Mar 2022Fusarium head blight (FHB) is one of the most important diseases affecting wheat production worldwide. In Mexico, and are the dominant species causing FHB of wheat...
Fusarium head blight (FHB) is one of the most important diseases affecting wheat production worldwide. In Mexico, and are the dominant species causing FHB of wheat (Cerón-Bustamante et al. 2018). During the 2017 to 2019 surveys, FHB symptoms were observed in wheat fields in the Highlands region of Mexico. Symptomatic spike samples were collected from 19 wheat fields in five states (Tlaxcala, Hidalgo, Puebla, Estado de México, and Morelos). -like colonies were consistently isolated on potato dextrose agar (PDA) and 95 monoconidial isolates were obtained. Morphological features of seven isolates were consistent with the description of the species complex (Xia et al. 2019). On PDA, colonies exhibited white and fluffy aerial mycelia, with diffused pink pigment on the reverse side after 7 days of incubation at 25℃. On carnation leaf agar (CLA), macroconidia (n = 100) were hyaline, falcate, with 3 to 6 septa, measuring 25.2 to 43.1 × 2.8 to 5.1 μm, and foot-shaped basal cell. Chlamydospores were ellipsoidal or subglobose and produced in chains. These seven isolates were selected for multilocus phylogenetic analysis and pathogenicity tests. Isolates were deposited in the Culture Collection of Phytopathogenic Fungi of the Department of Agricultural Parasitology at the Chapingo Autonomous University under acc. nos. UACH428 to UACH434. For molecular identification, genomic DNA was extracted, and the internal transcribed spacer (ITS) region, partial sequences of translation elongation factor 1-alpha (EF1-α) and the second largest subunit of RNA polymerase II (RPB2) genes were amplified, and sequenced with the primer sets ITS5/ITS4 (White et al. 1990), EF1-728F/EF1-986R (Carbone and Kohn 1999), and RBP2-5F/RPB2-7R (Liu et al. 1999), respectively. A phylogenetic tree, including published ITS, EF1-α, and RPB2 sequence data, was constructed for the species complex (FIESC) based on Maximum Likelihood. Three species of the FIESC were identified into (five isolates), (one isolate), and (one isolate). The sequences were deposited in GenBank with accession nos. OL347713 to OL347719 for ITS, OL365078 to OL365084 for EF1-α, and OL365072 to OL365077 for RPB2. The pathogenicity of the isolates was confirmed on wheat cv. Nana F2007 at the flowering stage in a glasshouse assay. The heads of 20 wheat plants were sprayed with a conidial suspension (1 × 10 spores/ml) of each isolate. Ten plants mock-inoculated with sterilized water served as the controls. All plants were placed in a moist chamber for 48 h. At 10 days after inoculation, typical FHB symptoms were visible on the inoculated plants, whereas the control plants remained asymptomatic. The pathogenicity test was repeated twice with similar results. The fungi were reisolated from the infected heads and found to be morphologically identical to the isolates used for inoculation, fulfilling Koch's postulates. Previously, three isolates of sp. belonging to the FIESC, were associated with FHB of wheat in Mexico (Cerón-Bustamante et al. 2018); however, this is the first report of , , and causing FHB of wheat in Mexico and worldwide (Farr and Rossman 2021). Further studies should be focused on determining the distribution, prevalence, and toxigenic potential of the isolates of the FIESC associated with wheat diseases in Mexico.
PubMed: 35285265
DOI: 10.1094/PDIS-11-21-2467-PDN -
Phytopathology Jan 2017Fusarium spp. are ranked among the top 10 most economically and scientifically important plant-pathogenic fungi in the world and are associated with plant diseases that...
Fusarium spp. are ranked among the top 10 most economically and scientifically important plant-pathogenic fungi in the world and are associated with plant diseases that include fruit decay of a number of crops. Fusarium isolates infecting bell pepper in Trinidad were identified based on sequence comparisons of the translation elongation factor gene (EF-1a) with sequences of Fusarium incarnatum-equiseti species complex (FIESC) verified in the FUSARIUM-ID database. Eighty-two isolates were identified as belonging to one of four phylogenetic species within the subclades FIESC-1, FIESC-15, FIESC-16, and FIESC-26, with the majority of isolates belonging to FIESC-15. A comparison of the level of DNA polymorphism and phylogenetic inference for sequences of the internal transcribed spacer region (ITS1-5.8S-ITS2) and EF-1a sequences for Trinidad and FUSARIUM-ID type species was carried out. The ITS sequences were less informative, had lower haplotype diversity and restricted haplotype distribution, and resulted in poor resolution and taxa placement in the consensus maximum-likelihood tree. EF-1a sequences enabled strongly supported phylogenetic inference with highly resolved branching patterns of the 30 phylogenetic species within the FIESC and placement of representative Trinidad isolates. Therefore, global phylogeny was inferred from EF-1a sequences representing 11 countries, and separation into distinct Incarnatum and Equiseti clades was again evident. In total, 42 haplotypes were identified: 12 were shared and the remaining were unique haplotypes. The most diverse haplotype was represented by sequences from China, Indonesia, Malaysia, and Trinidad and consisted exclusively of F. incarnatum isolates. Spain had the highest haplotype diversity, perhaps because both F. equiseti and F. incarnatum sequences were represented; followed by the United States, which contributed both F. equiseti and F. incarnatum sequences to the data set; then by countries representing Southeast Asia (China, Indonesia, Malaysia, Thailand, and Philippines) and Trinidad; both of these regions were represented by only F. incarnatum sequences. Trinidad shared two haplotypes with China and one haplotype with the United States for only F. incarnatum isolates. The findings of this study are important for devising disease management strategies and for understanding the phylogenetic relationships among members of the FIESC.
Topics: Asia, Southeastern; DNA, Fungal; Fungal Proteins; Fusarium; Geography; Haplotypes; Phylogeny; Plant Diseases; Sequence Analysis, DNA; Spain; United States
PubMed: 27901448
DOI: 10.1094/PHYTO-05-16-0209-R -
Plant Disease Apr 2022Fungal diseases, including sheath rot (), cause significant losses of yield and milling quality of rice (). In August 2021, symptoms like sheath rot were observed on 20%...
Fungal diseases, including sheath rot (), cause significant losses of yield and milling quality of rice (). In August 2021, symptoms like sheath rot were observed on 20% of rice plants (cv. Presidio) in 1-hectare field in Eagle Lake, Texas. Initial lesions occurred on the upper flag leaf sheaths and were oblong or irregular oval, with gray to light brown centers, and a dark reddish-brown diffuse margin. Lesions enlarged, coalesced, and covered a large area of the sheath. Infection led to panicle rot with kernels turning dark brown. Unlike sheath rot, sheath infection also led to inside culm infection with irregular dark brown lesions. Infected tissue pieces were sterilized with 1% NaOCl for 2 min, followed by 75% ethanol for 30 s, washed in sterile H2O three times, air dried and incubated on PDA at 27℃. Fungal isolates were obtained from 15 diseased plant samples and their singled-spored fungal colonies were whitish, loosely floccose and produced light yellow pigmentation. On carnation leaf agar, macroconidia were slightly curved and tapered at the ends, with 3 to 5 septa, and measured 17.5 to 34.3 × 3.1 to 5.0 µm. Microconidia were ovoid, usually with 0 to 1 septum and were 4.0 to 15.5 × 2.5 to 4.5 µm. Spherical shaped chlamydospores were produced in chain. These morphological characteristics were consistent to those described for species complex (O'Donnell et al. 2009), including (Wang et al. 2021) and (Avila et al. 2019). For molecular identification, DNA of a representative isolate was extracted and ITS, LSU, and EF1 of the fungus were amplified using the primers of ITS1/ITS4 (Wang et al. 2014), D1/D2 domain region of LSU (Fell et al. 2000), and EF1 (Wang et al. 2014), respectively, and sequenced. The ITS sequence (OL344049) was 99.61% identical to species complex (FD_01692) in Fusarium-ID database and 99.61% identical to (LC514690, KY523100, MW016539) and (MH979697) in NCBI database. The LSU sequence (OK559512) was 98.77% similar to (MN877913, MN368509) and (MH877332, MH877326); the EF1 sequence (OK570044) was 99.27% similar to (MK278902) in NCBI database. A phylogenetic analysis based on the concatenated nucleotide sequences grouped this isolate in the species complex clade at 100% bootstrap support. To evaluate pathogenicity, a conidial suspension of 1 x 10 conidia/ml or sterilized water (the controls) was injected into the sheaths and young panicles of three rice plants (cv. Presidio) at boot. Treated plants were maintained in a greenhouse at 25 to 30℃. After 3 weeks, typical symptoms, like those observed in the field, developed on the inoculated plants but not on the controls. The same fungus was consistently re-isolated from the diseased plants. To our knowledge, this is the first report of Fusarium sheath rot caused by species complex in rice in the U. S. species complex has been reported to be associated with panicle infection in wild rice () in Brazil (Tralamazza et al. 2021). has also been reported to cause panicle rot in China (Wang et al. 2021). has been reported to cause Fusarium sheath rot in India (Prabhukarthikeyan et al. 2021) and the U. S. (Cartwright et al. 1995). This research demonstrates the potential of different pathogens being involved in causing sheath rot of rice.
PubMed: 35486602
DOI: 10.1094/PDIS-12-21-2693-PDN -
Plant Disease Feb 2021Litchi (Litchi chinensis Sonn.) is an indigenous tropical and subtropical fruit in Southern China with an attractive appearance, delicious taste, and good nutritional...
Litchi (Litchi chinensis Sonn.) is an indigenous tropical and subtropical fruit in Southern China with an attractive appearance, delicious taste, and good nutritional value (Jiang et al. 2003). In March 2020, brown rots were observed on nearly ripe litchi fruits (cv. Guihuaxiang) in an orchard of Lingshui county, Hainan province of China (18.615877° N, 109.948871° E). About 5% fruits were symptomatic in the field, and the disease caused postharvest losses during storage. The initial infected fruits had no obvious symptoms on the outer pericarp surfaces, but appeared irregular, brown to black-brown lesions in the inner pericarps around the pedicels. Then lesions expanded and became brown rots. Small tissues (4 mm × 4 mm) of fruit pericarps were cut from symptomatic fruits, surface-sterilized in 1% sodium hypochlorite for 3 min, rinsed in sterilized water three times, plated on potato dextrose agar (PDA) and incubated at 28℃ in the darkness. Morphologically similar colonies were isolated from 85% of 20 samples after 4 days of incubation. Ten isolates were purified using a single-spore isolation method. The isolates grown on PDA had abundant, fluffy, whitish to yellowish aerial mycelia, and the reverse side of the Petri dish was pale brown. Morphological characteristics of conidia were further determined on carnation leaf-piece agar (CLA) (Leslie et al. 2006). Macroconidia were straight to slightly curved, 3- to 5-septates with a foot-shaped basal cell, tapered at the apex, 2.70 to 4.43 µm × 18.63 to 37.58 µm (3.56 ± 0.36 × 28.68 ± 4.34 µm) (n = 100). Microconidia were fusoid to ovoid, 0- to 1-septate, 2.10 to 3.57 µm × 8.18 to 18.20 µm (2.88 ± 0.34 × 11.71 ± 1.97 µm) (n = 100). Chlamydospores on hyphae singly or in chains were globose, subglobose, or ellipsoidal. Based on cultural features and morphological characteristics, the fungus was identified as a Fusarium species (Leslie et al. 2006). To further confirm the pathogen, DNA was extracted from the 7-day-old aerial mycelia of three isolates (LZ-1, LZ-3, and LZ-5) following Chohan et al. (2019). The sequences of the internal transcribed spacer region of rDNA (ITS), translation elongation factor-1 alpha (tef1) gene, and histone H3 (his3) gene were partially amplified using primers ITS1/ITS4, EF1-728F/EF1-986R, and CYLH3F/CYLH3R, respectively (Funnell-Harris et al. 2017). The nucleotide sequences were deposited in GenBank (ITS: 515 bp, MW029882, 533 bp, MW092186, and 465 bp, MW092187; tef1: 292 bp, MW034437, 262 bp, MW159143, and 292 bp, MW159141; his3: 489 bp, MW034438, 477 bp, MW159142, and 474 bp, MW159140). The ITS, tef1, and his3 genes showed 99-100% similarity with the ITS (MH979697), tef1 (MH979698), and his3 (MH979696) genes, respectively of Fusarium incarnatum (TG0520) from muskmelon fruit. The phylogenetic analysis of the tef1 and his3 gene sequences showed that the three isolates clustered with F. incarnatum. Pathogenicity tests were conducted by spraying conidial suspension (1×106 conidia/ml) on wounded young fruits in the orchid. Negative controls were sprayed with sterilized water. Fruits were bagged with polythene bags for 24 hours and then unbagged for 10 days. Each treatment had 30 fruits. The inoculated fruits developed symptoms similar to those observed in the orchard and showed light brown lesions on the outer pericarp surfaces and irregular, brown to black-brown lesions in the inner pericarps, while the fruits of negative control remained symptomless. The same fungus was successfully recovered from symptomatic fruits, and thus, the test for the Koch's postulates was completed. F. semitectum (synonym: F. incarnatum) (Saha et al. 2005), F. oxysporum (Bashar et al. 2012), and F. moniliforme (Rashid et al. 2015) have been previously reported as pathogens causing litchi fruit rots in India and Bangladesh. To our knowledge, this is the first report of Fusarium incarnatum causing litchi fruit rot in China.
PubMed: 33529072
DOI: 10.1094/PDIS-11-20-2393-PDN -
The Plant Pathology Journal Jun 2022Fusarium incarnatum-equiseti species complex (FIESC) contain over 40 members. The primer pair Smibo1FM/Semi1RM on the RPB2 partial gene has been reported to be able to...
Fusarium incarnatum-equiseti species complex (FIESC) contain over 40 members. The primer pair Smibo1FM/Semi1RM on the RPB2 partial gene has been reported to be able to identify Fusarium semitectum. The F. fujikuroi species complex (FFSC) contains more than 50 members. The F. verticillioides as a member of this complex can be identified by using VER1/VER2 primer pair on the CaM partial gene. In this research, the Smibo1FM/Semi1RM can amplify F. sulawesiense, F. hainanense, F. bubalinum, and F. tanahbumbuense, members of FIESC at 424 bp. The VER1/VER2 can amplify F. verticillioides, F. andiyazi, and F. pseudocircinatum, members of FFSC at 578 bp. Polymerase chain reaction-restriction fragment length polymorphism by using the combination of three restriction enzymes EcoRV, MspI, and HpyAV can differentiate each species of FIESC used. The two restriction enzymes HpaII and NspI can distinguish each species of FFSC used. The proper identification process is required for pathogen control in the field in order to reduce crop yield loss.
PubMed: 35678059
DOI: 10.5423/PPJ.NT.12.2021.0184 -
Journal of Fungi (Basel, Switzerland) Nov 2022spp. are among the most important plant pathogens in the world. A survey on maize leaf blight was carried out in Heilongjiang province from 2019 to 2021. Based on...
spp. are among the most important plant pathogens in the world. A survey on maize leaf blight was carried out in Heilongjiang province from 2019 to 2021. Based on morphological characteristics and a phylogenetic analysis on translation elongation factor () and second-largest subunit of RNA polymerase II () genes, 146 isolates were obtained and grouped into 14 species, including (20.5%), (17.1%), (9.59%), (9.59%), (8.9%), (6.85%), (6.85%), (5.48%), (5.48%), (2.74%), (2.74%), sp. (2.05%), (1.4%), and (0.68%). The species complex (FIESC, including , , , and ) was the most prevalent, indicating an evolving occurrence of the Fusarium species causing maize leaf blight. The typical symptoms observed on the maize leaves were oval to long strip lesions, with a gray to dark gray or brownish red coloration in the center and a chlorotic area at the edges. Based on the gene, seven haplotypes of FIESC were identified in Heilongjiang province, suggesting a population expansion. This is the first report of , , , , , , , , , , ., and causing maize leaf blight in Heilongjiang province, China. The current research is informative for managing disease, exploring the phylogenetic relationship among species, and clarifying the diversity of Fusarium species associated with maize leaf blight.
PubMed: 36354937
DOI: 10.3390/jof8111170 -
Plant Disease Apr 2022Muskmelon (Cucumis melo L.) is an economically important fruit crop in Taiwan. In March 2020, the symptoms of fruit rot were observed in approximately 10% of mature...
Muskmelon (Cucumis melo L.) is an economically important fruit crop in Taiwan. In March 2020, the symptoms of fruit rot were observed in approximately 10% of mature muskmelon fruits in a field located in Wuri (24.043585, 120.657588), Taichung City, Taiwan. Symptoms including water-soaked lesions were initially observed on the lwer side of fruit, extending with time to cover most of the fruit area, and internal dissolution with white to brown mycelia on the surface was also observed. Ten rotted fruits were disinfested with 70% ethanol for 1 min followed by 1% NaOCl for 5 min, then rinsed three times with sterile distilled water (SDW). Fifteen sterilized symptomatic fruit fragments were cut into 1-cm3 pieces, placed on potato dextrose agar (PDA) amended with 35 mg/liter of streptomycin sulfate and incubated at 28°C in the dark for 1 week. Ten isolates with similar morphology were obtained and the representative isolate FOS-1 was characterized further. Single-spore isolates were used for morphological and molecular analyses. Isolates grown on PDA had dense, cottony white aerial mycelium, changed to light brown, and with the time yellowish-brown pigmentation appeared. Microconidia were ovoid, fusiform, or slightly curved, 0 to1 septate, and ranged between 7.9 to 16.5 × 2.8 to 3.5 μm. Macroconidia were 3 to 5 septate, with a slightly curved and tapering apical cell, and ranged between 18.7 to 35.1 × 3.3 to 4.1 μm. Spherical chlamydospores with thick walls were abundant and single, being produced in terminal or intercalary position. Based on morphological characteristics, the fungus was identified as Fusarium sp. (Leslie and Summerell 2006). PCR amplification and DNA sequencing were performed using primers ITS1/ITS4 (White et al. 1990) and EF1-728F/EF1-986R (Carbone and Kohn 1999) to amplify the complete internal transcribed spacer (ITS) region and the partial translation elongation factor 1-alpha (TEF1-α) gene, respectively. The ITS and TEF1-α gene sequences of Isolate FOS-1 were deposited in GenBank database with acc. nos. MZ749694.1 and MZ782277.1, respectively. BLAST analysis showed 99.64% and 100% sequence identity with F. incanatum-equiseti species complex (FIESC) with MT563419.1 for ITS and MW034437.1 for EF-1α, respectively. BLAST analysis of TEF1-α gene sequence in FUSARIUM-ID database (Geiser et al. 2004), showed 99.31% sequence identity with FIESC (NRRL34070). Pathogenicity was confirmed by fulfilling Koch's postulates. Three healthy muskmelon fruit were disinfested using 70% ethanol for 30 s and 1% NaOCl for 5 min, and followed by three rinses with SDW. Then, the fruit were wounded using a sterile needle and inoculated with an 8 mm-mycelium agar plug. Three sites per fruit were inoculated, and three other fruits treated with mycelium-free PDA plugs served as the controls. The inoculated and control fruit were placed in a plastic box and incubated at 25°C under a 12 h photoperiod for 1 week. All inoculated fruit showed symptoms similar to those observed in the field, whereas no symptoms occurred on the controls. The fungus was re-isolated from the infected fruit, and identified as FIESC by the morphological and molecular methods described above. This pathogen could cause great losses in muskmelon. Members of the FIESC have been reported to cause leaf spot and fruit rot in muskmelon (Cao et al. 2019; Ismail et al. 2021). To our knowledge, this is the first report of the FIESC causing fruit rot of muskmelon in Taiwan. References: Cao, P., et al. 2019. Plant Dis.103:1768. Carbone, I., and Kohn, L. M. 1999. Mycologia. 91:553. Geiser, D.M., et al. 2004. Eur. J. Plant Pathol. 110:473. Ismail, S. I., et al. 2021. Plant Dis. 105:1197. Leslie, J. F., and Summerell, B. A. 2006. The Fusarium Laboratory Manual. Blackwell Publishing, Oxford, U.K. White, T. J., et al. 1990. PCR Protocols: A Guide to Methods and Applications Academic Press, San Diego, CA. 315.
PubMed: 35467940
DOI: 10.1094/PDIS-12-21-2624-PDN -
Plant Disease Jan 2021Rice (Oryza sativa L.) is the most important and widely grown crop, covering about 29.9 million ha of total cultivation area in China. In the last decade, spikelet rot...
Rice (Oryza sativa L.) is the most important and widely grown crop, covering about 29.9 million ha of total cultivation area in China. In the last decade, spikelet rot disease on rice became much more frequent in the middle and lower reaches of the Yangtze River, China. Fusarium proliferatum (Matsush.) Nirenberg ex Gerlach & Nirenberg was reported to be a causal agent of spikelet rot on rice in Hangzhou, Zhejiang province (Huang et al. 2012). In September 2019, a survey was conducted to understand the etiology of the disease in the main rice growing regions of Jinshan District of Shanghai. Symptomatic panicles exhibiting reddish or brown discoloration on the glumes were collected from different rice fields, where disease incidence was estimated to be between 20 to 80%. Diseased glumes were cut into small sections (5 × 5 mm) from the boundary of necrotic and healthy tissues, surface-sterilized with 75% ethanol for 30 s and 3% sodium hypochlorite for 90 s, rinsed twice with sterile distilled water, then placed onto 1/5 strength potato dextrose agar (PDA). After 3 to 5 days of incubation at 28°C in the dark, fungal growth with Fusarium-like colonies were transferred to PDA and purified by the single-spore isolation method. A total of 12 isolates were obtained and colonies showed loosely floccose, white mycelium and pale-yellow pigmentation on PDA. Microconidia were ovoid mostly with 0 to 1 septum, and measured 4.2 to 16.6 × 2.5 to 4.1 μm (n = 50). After 5-7 days of inoculation on carnation leaf agar (CLA), macroconidia produced usually had 3 to 5 septa, slightly curved at the apex, ranging from 15.7 to 39.1 × 3.3 to 5.0 μm (n = 50). Chlamydospores were produced in hyphae, most often solitary in short chains or in clumps, ellipsoidal or subglobose with thick and roughened walls. Molecular identification was performed on the representative isolates (JS3, JS9, and JS21). The rDNA internal transcribed spacer (ITS), translation elongation factor (TEF-1α) and β-tubulin (β-TUB) genes were amplified and sequenced using the paired primers ITS1/ITS4 (White et al. 1990), EF1/EF2 (O'Donnell et al. 1998) and T1/T22 (O'Donnell and Cigelnik 1997), respectively. The obtained sequences were deposited in GenBank under accession numbers MT889972 to MT889974 (ITS), MT895844 to MT895846 (TEF-1α), and MT895841 to MT895843 (β-TUB), respectively. BLASTn search of the sequences revealed 99 to 100% identity with ITS (MF356578), TEF-1α (HM770725) and β-TUB (GQ915444) of Fusarium incarnatum isolates. FUSARIUM-ID (Geiser et al. 2004) analysis showed 99 to 100% similarity with sequences of the F. incarnatum-equiseti species complex (FIESC) (FD_01651 and FD_01628). In addition, a phylogenetic analysis based on the concatenated nucleotide sequences placed the isolates in the F. incarnatum clade at 100% bootstrap support. Thus, both morphological observations and molecular criteria supported identification of the isolates as F. incarnatum (Desm.) Sacc (synonym: Fusarium semitectum) (Leslie and Summerell 2006, Nirenberg 1990). Pathogenicity tests were performed on susceptible rice cultivar 'Xiushui134'. At pollen cell maturity stage, a 2-ml conidial suspension (5 × 105 macroconidia/ml) of each isolate was injected into 10 rice panicles. Control plants were inoculated with sterile distilled water. Then, the pots were kept in a growth chamber at 28°C, 80% relative humidity, and 12 h/12 h light (10,000 lux)/dark. The experiment was repeated two times for each isolate. Two weeks post-inoculation, all inoculated panicles showed similar symptoms with the original samples, whereas no symptoms were observed on the control. The pathogen was re-isolated from inoculated panicles and identified by the method described above to fulfill Koch's postulates. Previous studies reported that F. incarnatum reproduced perithecia to overwinter on rice stubble as the inoculum of Fusarium head blight of wheat in southern China (Yang et al. 2018). To our knowledge, this is the first report of spikelet rot on rice caused by F. incarnatum in China. Further investigation is needed to gain a better understanding its potential geographic distribution of this new pathogen on rice crop. References: (1) Huang, S. W., et al. 2011. Crop Prot. 30: 10. (2) White, T. J., et al. 1990. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA. (3) O'Donnell, K., et al. 1998. Proc. Natl. Acad. Sci. U.S.A. 95: 2044. (4) O'Donnell, K., Cigelnik, E. 1997. Mol. Phylogenet. Evol. 7: 103. (5) Geiser, D. M., et al. 2004. Eur. J. Plant Pathol. 110: 473. (6) Leslie, J. F., and Summerell, B. A. 2006. The Fusarium Laboratory Manual. Blackwell, Ames, IA. (7) Nirenberg, H. I. 1990. Stud. Mycol. 32: 91. (8) Yang, M. X., et al. 2018. Toxins. 10: 115. The author(s) declare no conflict of interest. Funding: Funding was provided by National Natural Science Foundation of China (grant no. 31800133), Zhejiang Provincial Natural Science Foundation of China (grant no. LQ18C140005), Key Research and Development Program of Zhejiang Province (grant no. 2019C02018), Shanghai Science and Technology for Agriculture Promotion Project (2019-02-08-00-08-F01127), and the Agricultural Science and Technology Innovation Program of China Academy of Agricultural Science (CAAS-ASTIP-2013- CNRRI).
PubMed: 33507100
DOI: 10.1094/PDIS-12-20-2660-PDN -
Journal of Clinical Microbiology Nov 2016Multilocus DNA sequence data were used to assess the genetic diversity and evolutionary relationships of 67 Fusarium strains from veterinary sources, most of which were...
Multilocus DNA sequence data were used to assess the genetic diversity and evolutionary relationships of 67 Fusarium strains from veterinary sources, most of which were from the United States. Molecular phylogenetic analyses revealed that the strains comprised 23 phylogenetically distinct species, all but two of which were previously known to infect humans, distributed among eight species complexes. The majority of the veterinary isolates (47/67 = 70.1%) were nested within the Fusarium solani species complex (FSSC), and these included 8 phylospecies and 33 unique 3-locus sequence types (STs). Three of the FSSC species (Fusarium falciforme, Fusarium keratoplasticum, and Fusarium sp. FSSC 12) accounted for four-fifths of the veterinary strains (38/47) and STs (27/33) within this clade. Most of the F. falciforme strains (12/15) were recovered from equine keratitis infections; however, strains of F. keratoplasticum and Fusarium sp. FSSC 12 were mostly (25/27) isolated from marine vertebrates and invertebrates. Our sampling suggests that the Fusarium incarnatum-equiseti species complex (FIESC), with eight mycoses-associated species, may represent the second most important clade of veterinary relevance within Fusarium Six of the multilocus STs within the FSSC (3+4-eee, 1-b, 12-a, 12-b, 12-f, and 12-h) and one each within the FIESC (1-a) and the Fusarium oxysporum species complex (ST-33) were widespread geographically, including three STs with transoceanic disjunctions. In conclusion, fusaria associated with veterinary mycoses are phylogenetically diverse and typically can only be identified to the species level using DNA sequence data from portions of one or more informative genes.
Topics: Animals; Cluster Analysis; Fusariosis; Fusarium; Molecular Epidemiology; Multilocus Sequence Typing; Phylogeny; Sequence Homology; United States
PubMed: 27605713
DOI: 10.1128/JCM.01607-16