ABSTRACT
Trichosanthes kirilowii (Chinese cucumber) is one of the important perennial herbaceous vines in China, with putative pharmacological activities including anti-tumor and lowering blood lipids. In July 2022, T. kirilowii plants with brownish roots and chlorotic leaves were observed in several orchards in Qianshan, Anhui province, China (30°34'N, 116° 30'E). The disease incidence reached approximately 10% within an area spanning 20 ha, and was higher in poorly drained orchards. To investigate this root rot disease, five symptomatic plants were collected from the diseased orchards in Qianshan. Subsequently, small sections of the diseased roots were surface sterilized using 1% sodium hypochlorite and 75% ethanol for 45 seconds each. Then, sterilized roots were placed onto PDA (20% diced potato, 2% glucose, and 1.5% agar, and distilled water) and incubated at 28â in the dark for 6 days. A total of eight isolates with similar morphology were obtained and purified by single spore culturing. Two representative isolates (QSJ4 and QSJ5) were chosen for further analysis. When grown on PDA, the surface of each colony was white with dense aerial mycelium and pale orange color in the center with a white edge on the reverse side. Macroconidia produced on carnation leaf agar plates were falcate, slightly curved, and 3 to 5 septate, with papillate apical cells and indistinct basal cells. Macroconidia were 17.4-42.3 × 2.4-5.8 µm (n = 100). Microconidia were ellipsoidal in shape, slightly curved or not curved, and most were 1-septate, 9.6-16.7 × 1.5-3.8 µm (n = 40). The identity was determined by sequencing four loci (i. e., ITS, CAL, EF1-α and RPB2) from two representative isolates (Liu et al. 1999; O'Donnell et al. 1998, 2000; Reeb et al. 2004; White et al. 1990). Sequences were deposited in GenBank [ITS (OR267397, OR267398), CAL (OR296634, OR296635), EF1-α (OR296637, OR296638) and RPB2 (OR296640, OR296641)]. A phylogenetic analysis was performed with three loci (CAL, EF1-α, RPB2) comprising a concatenated dataset of 68 strains in the Fusarium incarnatum-equiseti species complex (Han et al., 2023). The results showed that isolates QSJ4 and QSJ5 clustered closely together with reference strains of F. sulawesiense. Pathogenicity tests were conducted by inoculating three-week-old healthy T. kirilowii seedings (cv. Wanlou No. 9) cultivated in substrate soil in pots with a diameter of 17 cm and a height of 10.5 cm. A 20 mL aliquot of spore suspension (106 conidia/mL) of F. sulawesiense was inoculated to the roots of potted seedlings by irrigation. Each strain was inoculated onto three seedlings. The potted seedlings were inoculated with sterile water as the negative control. Inoculated seedlings were incubated in a growth chamber at 25â and 75% relative humidity. After one week, typical symptoms of root necrosis and leaf chlorosis were observed on the inoculated seedlings. Disease symptoms were not observed on the control seedlings. All seedlings showing root necrosis and leaf chlorosis caused by the inoculations were subjected to fungal isolation, and the results showed that the reisolated colonies matched the inoculated ones for morphologies and ITS sequences. Fusarium sulawesiense has been previously reported to cause disease on Cucumis melo L. in Brazil (Medeiros Araujo et al. 2021), Musa acuminata Colla in south Sulawesi (Maryani et al. 2019), Luffa aegyptiaca Miller and Musa nana Lour. in China (Wang et al. 2019). To our knowledge, this is the first report of F. sulawesiense causing Fusarium root rot of T. kirilowii in China.
ABSTRACT
The genera Cephalotrichum and Microascus contain ecologically, morphologically and lifestyle diverse fungi in Microascaceae (Microascales, Sordariomycetes) with a world-wide distribution. Despite previous studies having elucidated that Cephalotrichum and Microascus are highly polyphyletic, the DNA phylogeny of many traditionally morphology-defined species is still poorly resolved, and a comprehensive taxonomic overview of the two genera is lacking. To resolve this issue, we integrate broad taxon sampling strategies and the most comprehensive multi-gene (ITS, LSU, tef1 and tub2) datasets to date, with fossil calibrations to address the phylogenetic relationships and divergence times among major lineages of Microascaceae. Two previously recognised main clades, Cephalotrichum (24 species) and Microascus (49 species), were re-affirmed based on our phylogenetic analyses, as well as the phylogenetic position of 15 genera within Microascaceae. In this study, we provide an up-to-date overview on the taxonomy and phylogeny of species belonging to Cephalotrichum and Microascus, as well as detailed descriptions and illustrations of 21 species of which eight are newly described. Furthermore, the divergence time estimates indicate that the crown age of Microascaceae was around 210.37 Mya (95 % HPD: 177.18-246.96 Mya) in the Late Triassic, and that Cephalotrichum and Microascus began to diversify approximately 27.07 Mya (95 % HPD: 20.47-34.37 Mya) and 70.46 Mya (95 % HPD: 56.96-86.24 Mya), respectively. Our results also demonstrate that multigene sequence data coupled with broad taxon sampling can help elucidate previously unresolved clade relationships. Citation: Wei TP, Wu YM, Zhang X, et al. 2024. A comprehensive molecular phylogeny of Cephalotrichum and Microascus provides novel insights into their systematics and evolutionary history. Persoonia 52: 119-160. https://doi.org/10.3767/persoonia.2024.52.05 .
ABSTRACT
Chaetomiaceae comprises phenotypically diverse species, which impact biotechnology, the indoor environment and human health. Recent studies showed that most of the traditionally defined genera in Chaetomiaceae are highly polyphyletic. Many of these morphology-based genera, such as Chaetomium, Thielavia and Humicola, have been redefined using multigene phylogenetic analysis combined with morphology; however, a comprehensive taxonomic overview of the family is lacking. In addition, the phylogenetic relationship of thermophilic Chaetomiaceae species with non-thermophilic taxa in the family is largely unclear due to limited taxon sampling in previous studies. In this study, we provide an up-to-date overview on the taxonomy and phylogeny of genera and species belonging to Chaetomiaceae, including an extensive taxon sampling of thermophiles. A multigene phylogenetic analysis based on the ITS (internal transcribed spacers 1 and 2 including the 5.8S nrDNA), LSU (D1/D2 domains of the 28S nrDNA), rpb2 (partial RNA polymerase II second largest subunit gene) and tub2 (ß-tubulin gene) sequences was performed on 345 strains representing Chaetomiaceae and 58 strains of other families in Sordariales. Divergence times based on the multi-gene phylogeny were estimated as aid to determine the genera in the family. Genera were delimited following the criteria that a genus must be a statistically well-supported monophyletic clade in both the multigene phylogeny and molecular dating analysis, fall within a divergence time of over 27 million years ago, and be supported by ecological preference or phenotypic traits. Based on the results of the phylogeny and molecular dating analyses, combined with morphological characters and temperature-growth characteristics, 50 genera and 275 species are accepted in Chaetomiaceae. Among them, six new genera, six new species, 45 new combinations and three new names are proposed. The results demonstrate that the thermophilic species fall into seven genera (Melanocarpus, Mycothermus, Remersonia, Thermocarpiscus gen. nov., Thermochaetoides gen. nov., Thermothelomyces and Thermothielavioides). These genera cluster in six separate lineages, suggesting that thermophiles independently evolved at least six times within the family. A list of accepted genera and species in Chaetomiaceae, together with information on their MycoBank numbers, living ex-type strains and GenBank accession numbers to ITS, LSU, rpb2 and tub2 sequences is provided. Furthermore, we provide suggestions how to describe and identify Chaetomiaceae species. Taxonomic novelties: new genera: Parvomelanocarpus X.Wei Wang & Houbraken, Pseudohumicola X.Wei Wang, P.J. Han, F.Y. Bai & Houbraken, Tengochaeta X.Wei Wang & Houbraken, Thermocarpiscus X.Wei Wang & Houbraken, Thermochaetoides X.Wei Wang & Houbraken, Xanthiomyces X.Wei Wang & Houbraken; New species: Botryotrichum geniculatum X.Wei Wang, P.J. Han & F.Y. Bai, Chaetomium subaffine Sergejeva ex X.Wei Wang & Houbraken, Humicola hirsuta X.Wei Wang, P.J. Han & F.Y. Bai, Subramaniula latifusispora X.Wei Wang, P.J. Han & F.Y. Bai, Tengochaeta nigropilosa X.Wei Wang & Houbraken, Trichocladium tomentosum X.Wei Wang, P.J. Han & F.Y. Bai; New combinations: Achaetomiella gracilis (Udagawa) Houbraken, X.Wei Wang, P.J. Han & F.Y. Bai, Allocanariomyces americanus (Cañete-Gibas et al.) Cañete-Gibas, Wiederhold, X.Wei Wang & Houbraken, Amesia dreyfussii (Arx) X.Wei Wang & Houbraken, Amesia raii (G. Malhotra & Mukerji) X.Wei Wang & Houbraken, Arcopilus macrostiolatus (Stchigel et al.) X.Wei Wang & Houbraken, Arcopilus megasporus (Sörgel ex Seth) X.Wei Wang & Houbraken, Arcopilus purpurascens (Udagawa & Y. Sugiy.) X.Wei Wang & Houbraken, Arxotrichum deceptivum (Malloch & Benny) X.Wei Wang & Houbraken, Arxotrichum gangligerum (L.M. Ames) X.Wei Wang & Houbraken, Arxotrichum officinarum (M. Raza & L. Cai) X.Wei Wang & Houbraken, Arxotrichum piluliferoides (Udagawa & Y. Horie) X.Wei Wang & Houbraken, Arxotrichum repens (Guarro & Figueras) X.Wei Wang & Houbraken, Arxotrichum sinense (K.T. Chen) X.Wei Wang & Houbraken, Botryotrichum inquinatum (Udagawa & S. Ueda) X.Wei Wang & Houbraken, Botryotrichum retardatum (A. Carter & R.S. Khan) X.Wei Wang & Houbraken, Botryotrichum trichorobustum (Seth) X.Wei Wang & Houbraken, Botryotrichum vitellinum (A. Carter) X.Wei Wang & Houbraken, Collariella anguipilia (L.M. Ames) X.Wei Wang & Houbraken, Collariella hexagonospora (A. Carter & Malloch) X.Wei Wang & Houbraken, Collariella pachypodioides (L.M. Ames) X.Wei Wang & Houbraken, Ovatospora amygdalispora (Udagawa & T. Muroi) X.Wei Wang & Houbraken, Ovatospora angularis (Yu Zhang & L. Cai) X.Wei Wang & Houbraken, Parachaetomium biporatum (Cano & Guarro) X.Wei Wang & Houbraken, Parachaetomium hispanicum (Guarro & Arx) X.Wei Wang & Houbraken, Parachaetomium inaequale (Pidopl. et al.) X.Wei Wang & Houbraken, Parachaetomium longiciliatum (Yu Zhang & L. Cai) X.Wei Wang & Houbraken, Parachaetomium mareoticum (Besada & Yusef) X.Wei Wang & Houbraken, Parachaetomium muelleri (Arx) X.Wei Wang & Houbraken, Parachaetomium multispirale (A. Carter et al.) X.Wei Wang & Houbraken, Parachaetomium perlucidum (Sergejeva) X.Wei Wang & Houbraken, Parachaetomium subspirilliferum (Sergejeva) X.Wei Wang & Houbraken, Parathielavia coactilis (Nicot) X.Wei Wang & Houbraken, Parvomelanocarpus tardus (X.Wei Wang & Samson) X.Wei Wang & Houbraken, Parvomelanocarpus thermophilus (Abdullah & Al-Bader) X.Wei Wang & Houbraken, Pseudohumicola atrobrunnea (X.Wei Wang et al.) X.Wei Wang, P.J. Han, F.Y. Bai & Houbraken, Pseudohumicola pulvericola (X.Wei Wang et al.) X.Wei Wang, P.J. Han, F.Y. Bai & Houbraken, Pseudohumicola semispiralis (Udagawa & Cain) X.Wei Wang, P.J. Han, F.Y. Bai & Houbraken, Pseudohumicola subspiralis (Chivers) X.Wei Wang, P.J. Han, F.Y. Bai & Houbraken, Staphylotrichum koreanum (Hyang B. Lee & T.T.T. Nguyen) X.Wei Wang & Houbraken, Staphylotrichum limonisporum (Z.F. Zhang & L. Cai) X.Wei Wang & Houbraken, Subramaniula lateralis (Yu Zhang & L. Cai) X.Wei Wang & Houbraken, Thermocarpiscus australiensis (Tansey & M.A. Jack) X.Wei Wang & Houbraken, Thermochaetoides dissita (Cooney & R. Emers.) X.Wei Wang & Houbraken, Thermochaetoides thermophila (La Touche) X.Wei Wang & Houbraken, Xanthiomyces spinosus (Chivers) X.Wei Wang & Houbraken; New names: Chaetomium neoglobosporum X.Wei Wang & Houbraken, Thermothelomyces fergusii X.Wei Wang & Houbraken, Thermothelomyces myriococcoides X.Wei Wang & Houbraken; Lecto- and / or epi-typifications (basionyms): Botryoderma rostratum Papendorf & H.P. Upadhyay, Botryotrichum piluliferum Sacc. & Marchal, Chaetomium carinthiacum Sörgel, Thielavia heterothallica Klopotek. Citation: Wang XW, Han PJ, Bai FY, Luo A, Bensch K, Meijer M, Kraak B, Han DY, Sun BD, Crous PW, Houbraken J (2022). Taxonomy, phylogeny and identification of Chaetomiaceae with emphasis on thermophilic species. Studies in Mycology 101: 121-243. doi: 10.3114/sim.2022.101.03.
ABSTRACT
In a recently published classification scheme for Leotiomycetes, the new family Hyphodiscaceae was erected; unfortunately, this study was rife with phylogenetic misinterpretations and hampered by a poor understanding of this group of fungi. This manifested in the form of an undiagnostic familial description, an erroneous familial circumscription, and the redescription of the type species of an included genus as a new species in a different genus. The present work corrects these errors by incorporating new molecular data from this group into phylogenetic analyses and examining the morphological features of the included taxa. An emended description of Hyphodiscaceae is provided, notes and descriptions of the included genera are supplied, and keys to genera and species in Hyphodiscaceae are supplied. Microscypha cajaniensis is combined in Hyphodiscus, and Scolecolachnum nigricans is a taxonomic synonym of Fuscolachnum pteridis. Future work in this family should focus on increasing phylogenetic sampling outside of Eurasia and better characterising described species to help resolve outstanding issues. Citation: Quijada L, Baral HO, Johnston PR, Pärtel K, Mitchell JK, Hosoya T, Madrid H, Kosonen T, Helleman S, Rubio E, Stöckli E, Huhtinen S, Pfister DH (2022). A review of Hyphodiscaceae. Studies in Mycology 103: 59-85. doi: 10.3114/sim.2022.103.03.
ABSTRACT
Fungi are incredibly diverse, but they are unexplored, especially in the subalpine and alpine zone. Mortierellaceae are certainly one of the most abundant, species-rich, and widely distributed cultivable soil fungal families in terrestrial habitats, including subalpine and alpine zones. The phylogeny of Mortierellaceae was recently resolved based on current state of the art molecular techniques, and the paraphyletic genus Mortierella sensu lato (s.l.) was divided into 13 monophyletic genera. Our extensive sampling campaigns in the Austrian Alps resulted in 139 different Mortierellaceae pure culture isolates representing 13 new species. For the definition of taxa, we applied both classical morphological criteria, as well as modern DNA-based methods. Phylogenetic relationships were resolved based on the ribosomal DNA internal transcribed spacer (rDNA ITS), the large subunit (LSU), and the DNA-directed RNA polymerase II largest subunit 1 (RPB1). In this study, we proposed a new genus and described 13 new species belonging to the genera Entomortierella, Linnemannia, Mortierella and Podila. In addition, we proposed eight new combinations, re-defined E. jenkinii at species level, defined a neotype for M. alpina and lecto- as well as epitypes for M. fatshederae, M. jenkinii, and M. longigemmata. The rDNA ITS region is generally applied as classical barcoding gene for fungi. However, the obtained phylogenetic resolution is often too low for an accurate identification of closely related species of Mortierellaceae, especially for small sampling sizes. In such cases, unambiguous identification can be obtained based on morphological characters of pure culture isolates. Therefore, we also provide dichotomous keys for species identification within phylogenetic lineages. Taxonomic novelties: new genus: Tyroliella Telagathoti, Probst & Peintner; New species: Entomortierella galaxiae Telagathoti, M. Probst & Peintner, Linnemannia bainierella Telagathoti, M. Probst & Peintner, Linnemannia stellaris Telagathoti, M. Probst & Peintner, Linnemannia nimbosa Telagathoti, M. Probst & Peintner, Linnemannia mannui Telagathoti, M. Probst & Peintner, Linnemannia friederikiana Telagathoti, M. Probst & Peintner, Linnemannia scordiella Telagathoti, M. Probst & Peintner, Linnemannia solitaria Telagathoti, M. Probst & Peintner, Mortierella triangularis Telagathoti, M. Probst & Peintner, Mortierella lapis Telagathoti, M. Probst & Peintner, Podila himami Telagathoti, M. Probst & Peintner, Podila occulta Telagathoti, M. Probst & Peintner, Tyroliella animus-liberi Telagathoti, Probst & Peintner; New combinations: Entomortierella basiparvispora (W. Gams & Grinb.) Telagathoti, M. Probst & Peintner, Entomortierella jenkinii (A.L. Sm.) Telagathoti, M. Probst & Peintner; Entomortierella sugadairana (Y. Takash. et al.) Telagathoti, M. Probst & Peintner, Linnemannia zonata (Linnem. ex W. Gams) Telagathoti, M. Probst & Peintner, Linnemannia fluviae (Hyang B. Lee et al.) Telagathoti, M. Probst & Peintner, Linnemannia biramosa (Tiegh.) Telagathoti, M. Probst & Peintner, Linnemannia cogitans (Degawa) Telagathoti, M. Probst & Peintner, Tyroliella pseudozygospora (W. Gams & Carreiro) Telagathoti, M. Probst & Peintner; Epitypifications (basionyms): Mortierella bainieri var. jenkinii A.L. Sm., Mortierella fatshederae Linnem., Mortierella longigemmata Linnem. Neotypification (basionym): Mortierella alpina Peyronel. Citation: Telagathoti A, Probst M, Mandolini E, Peintner U (2022). Mortierellaceae from subalpine and alpine habitats: new species of Entomortierella, Linnemannia, Mortierella, Podila and Tyroliella gen. nov. Studies in Mycology 103: 25-58. doi: 10.3114/sim.2022.103.02.
ABSTRACT
Michelia macclurei Dandy is an excellent timber and ornamental tree native to South China (Lan et al. 2010). In May 2020, a leaf spot disease of M. macclurei was found on the campus of Jiangxi Agricultural University (N28°45'56â³, E115°50'21â³). Approximately 25% (9 out of 35) of 32-year-old M. macclurei trees showed the leaf spot disease. On average, 40% of the leaves per individual tree were affected. The symptoms began as small dark brown lesions formed along the leaf margins and tips. The lesions' center was sunken with a dark brown border as the disease developed. Thirty pieces (5 × 5 mm) from the lesion margins were surface sterilized in 70% ethanol (30 s), then in 3% NaOCl (1 min), and finally rinsed three times with sterile water. Leaf pieces were placed on potato dextrose agar (PDA) and incubated at 25°C. Pure cultures were obtained by monosporic isolation. Sixteen strains with similar morphological characterizations were isolated, and three representative isolates (HX-1, HX-2, HX-3) were used for morphological and molecular characterization. The three isolates were white, cottony, and light gray on the reverse, producing dark-green pigmentation near the center. The conidia were single-celled, straight, hyaline, cylindrical, clavate, and measured 12.8-17.5 × 4.5-5.7 µm (14.7 ± 1.2 × 4.8 ± 0.2 µm, n = 100). Appressoria were brown to dark brown, ovoid to clavate, and ranged from 5.9-8.8 × 4.4-6.7 µm (7.1 ± 0.6 × 5.6 ± 0.6 µm, n=100). The internal transcribed spacer (ITS) regions, actin (ACT), calmodulin (CAL), chitin synthase (CHS-1), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and beta-tubulin2 (TUB2) were sequenced using the primers ITS1/ITS4 (White et al. 1990), ACT-512F/ACT-783R, CL1/CL2, CHS-79F/CHS-345R, GDF/GDR, and T1/Bt2b, respectively (Weir et al. 2012). The sequences were deposited into GenBank (Accession Nos.: MZ323328, MZ323329, MW581269 for ITS, MZ889002, MZ889003, MW661166 for ACT, MZ889004, MZ889005, MW661167 for CAL, MZ889006, MZ889007, MW661168 for CHS-1, MZ889008, MZ889009, MW661169 for GAPDH, MZ889010, MZ889011, MW661170 for TUB2). A maximum likelihood and Bayesian posterior probability-based analyses using IQ-tree v. 1.6.8 and Mr. Bayes v. 3.2.6 with the concatenated sequences (ITS, ACT, CAL, CHS-1, GAPDH, and TUB2 ) placed three isolates in the clade of Colletotrichum siamense Prihastuti, L. Cai & K. D. Hyde. Based on the morphological characteristics and molecular data, three isolates were identified as C. siamense (Fu et al. 2019).The pathogenicity of each isolate was tested on potted 2-yr-old seedlings of M. macclurei grown in a greenhouse at 25 â, 70% relative humidity with a 12-h photoperiod. Twenty healthy leaves on 10 M. macclurei plants were inoculated with 10 µL of spore suspension (106 conidia/mL). Another 20 healthy leaves were inoculated with sterile water as the control. All leaves were wounded with a sterile needle (Φ=0.5 mm). The resulting symptoms were similar to those on the original infected plants, whereas the control leaves remained asymptomatic for 8 days after inoculation. C. siamense was consistently re-isolated only from the diseased leaves, fulfilling Koch's postulates. C. siamense can cause leaf diseases in a variety of hosts, such as Salix matsudana (Zhang et al. 2021), Liriodendron chinense [Hemsl.] Sarg. × tulipifera L. (Zhu et al. 2019) and Magnolia grandiflora (Zhou et al. 2022). This is the first report of C. siamense associated with leaf spot disease on M. macclurei in China, and its potential threat should be evaluated in the future. These results will help to develop effective strategies for appropriately managing this newly emerging disease.
ABSTRACT
Schima superba Gardn. et Champ. is a subtropical evergreen tree species naturally distributed mainly in China, Japan, and Vietnam. It is primarily planted for its timber and urban landscaping in China (Ni, 1996). In September 2018, leaves necrotic spots were observed on S. superba in Jiangxi Forest Breeding Center (28°57'19.52" N, 115°39'21.32" E), Jiangxi Province, China. The disease incidence was about 30%. Initially, spots were circular to semicircular, grayish-brown in the center with dark brown margin, then expanded and eventually collapsed into sunken necrotic lesions. To identify the agent, diseased leaves were collected randomly. Pieces (5 × 5 mm) from the lesion borders were surfaced sterilized in 70% ethanol (30 s), 3% NaOCl (60 s), and rinsed 3 times in sterile water. These pieces were put on potato dextrose agar (PDA) and cultured at 25 °C. Pure cultures were obtained by monosporic isolation, and 3 isolates (MH-1, MH-2, MH-3) were used for morphological studies and phylogenetic analyses. On PDA, colonies were initially white, cottony, then became pinkish to deep-pink at the center and pink on the reverse. Conidia were fusiform with acute ends, smooth-walled, hyaline, 13.7-18.5 × 4.6-6.1 µm (16.4 ± 1.3× 5.3 ± 0.6 µm, n = 100). Conidiophores were colorless to pale brown, smooth, septate. Conidiogenous cells were colorless to pale brown, smooth, cylindrical to ampulliform. The morphological characteristics fit the descriptions of Colletotrichum acutatum J. H. Simmonds sensu lato (Damm et al., 2012). For accurate identification, genomic DNA of 3 isolates was extracted, and the internal transcribed spacer (ITS), actin (ACT), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), beta-tubulin 2 (TUB2), and chitin synthase (CHS-1) were amplified and sequenced using the corresponding primers (Weir et al., 2012). The sequences were deposited in GenBank (ITS: MZ325946, MZ325947, MW584318; ACT: MZ399375, MZ419566, MW661171; CHS-1: MZ399376, MZ419567, MW661172; MZ399377, GAPDH: MZ419568, MW661173; TUB2: MZ399378, MZ419569, MW661174). Five loci were concatenated, and the aligned sequences (1528bp) were 99.89% homologous to ex-type C. fioriniae (Marcelino & Gouli) R. G. Shivas & Y. P. Tan CBS128517. Phylogenetic analysis using the maximum likelihood showed that 3 isolates were clustered in C. fioriniae clade with 100% bootstrap support. Based on the multi-locus phylogeny and morphology, 3 isolates were identified as C. fioriniae. Pathogenicity tests were performed on 36 seedlings of S. superba (2-year-old). The leaves were wounded slightly and inoculated with a drop of spore suspension (106 conidia/mL). The sterile water was used as controls. All the tested leaves were covered with black plastic bags to keep them moist for 2 days. All seedlings were placed in the greenhouse (25 °C, 12 h light/dark) for 10 days, and all inoculated leaves had typical symptoms. The controls were asymptomatic. The same fungus was reisolated from the lesions, fulfilling Koch's postulates. Colletotrichum fioriniae was described as a new species from the C. acutatum s. l. (Shivas et al., 2009), and it was an important plant pathogen, such as Pyrus spp. (Pavlovic et al., 2019), Morus alba L. (Xue et al., 2019), and so on. This is the first report of the newly emerging disease of S. superba caused by C. fioriniae in the world, and its potential threat should be evaluated in the future. This study provided crucial information for epidemiologic studies and appropriate control strategies.
ABSTRACT
Recent publications have argued that there are potentially serious consequences for researchers in recognising distinct genera in the terminal fusarioid clade of the family Nectriaceae. Thus, an alternate hypothesis, namely a very broad concept of the genus Fusarium was proposed. In doing so, however, a significant body of data that supports distinct genera in Nectriaceae based on morphology, biology, and phylogeny is disregarded. A DNA phylogeny based on 19 orthologous protein-coding genes was presented to support a very broad concept of Fusarium at the F1 node in Nectriaceae. Here, we demonstrate that re-analyses of this dataset show that all 19 genes support the F3 node that represents Fusarium sensu stricto as defined by F. sambucinum (sexual morph synonym Gibberella pulicaris). The backbone of the phylogeny is resolved by the concatenated alignment, but only six of the 19 genes fully support the F1 node, representing the broad circumscription of Fusarium. Furthermore, a re-analysis of the concatenated dataset revealed alternate topologies in different phylogenetic algorithms, highlighting the deep divergence and unresolved placement of various Nectriaceae lineages proposed as members of Fusarium. Species of Fusarium s. str. are characterised by Gibberella sexual morphs, asexual morphs with thin- or thick-walled macroconidia that have variously shaped apical and basal cells, and trichothecene mycotoxin production, which separates them from other fusarioid genera. Here we show that the Wollenweber concept of Fusarium presently accounts for 20 segregate genera with clear-cut synapomorphic traits, and that fusarioid macroconidia represent a character that has been gained or lost multiple times throughout Nectriaceae. Thus, the very broad circumscription of Fusarium is blurry and without apparent synapomorphies, and does not include all genera with fusarium-like macroconidia, which are spread throughout Nectriaceae (e.g., Cosmosporella, Macroconia, Microcera). In this study four new genera are introduced, along with 18 new species and 16 new combinations. These names convey information about relationships, morphology, and ecological preference that would otherwise be lost in a broader definition of Fusarium. To assist users to correctly identify fusarioid genera and species, we introduce a new online identification database, Fusarioid-ID, accessible at www.fusarium.org. The database comprises partial sequences from multiple genes commonly used to identify fusarioid taxa (act1, CaM, his3, rpb1, rpb2, tef1, tub2, ITS, and LSU). In this paper, we also present a nomenclator of names that have been introduced in Fusarium up to January 2021 as well as their current status, types, and diagnostic DNA barcode data. In this study, researchers from 46 countries, representing taxonomists, plant pathologists, medical mycologists, quarantine officials, regulatory agencies, and students, strongly support the application and use of a more precisely delimited Fusarium (= Gibberella) concept to accommodate taxa from the robust monophyletic node F3 on the basis of a well-defined and unique combination of morphological and biochemical features. This F3 node includes, among others, species of the F. fujikuroi, F. incarnatum-equiseti, F. oxysporum, and F. sambucinum species complexes, but not species of Bisifusarium [F. dimerum species complex (SC)], Cyanonectria (F. buxicola SC), Geejayessia (F. staphyleae SC), Neocosmospora (F. solani SC) or Rectifusarium (F. ventricosum SC). The present study represents the first step to generating a new online monograph of Fusarium and allied fusarioid genera (www.fusarium.org).
ABSTRACT
Mu oil tree (Vernicia montana) is an economically important woody oil plant, which is widely distributed in southern China. In mid-May 2020, a leaf spot disease was observed on the leaves of mu oil tree in Taihe County in Jiangxi Province, China (26°55'25.55â³N, 114°49'5.85â³E). The disease incidence was estimated to be above 40%. Initial symptoms were circular red-brown spots which were 1-2 mm in diameter, then enlarged with red-brown center. In later stages, the spots coalesced and formed large patches, and subsequently red-brown centers of lesions gradually dried and fell out, forming a "shot hole" appearance. To identify the pathogen, diseased leaves were collected from Taihe County. Leaf tissues (5 × 5 mm) were cut from the margins of typical symptomatic lesions, surface- sterilized in 75% ethanol for 30 seconds and 3% sodium hypochlorite for 60 seconds, then rinsed with sterile distilled water three times. Leaf pieces were placed on potato dextrose agar (PDA; 1.5%, Difco-BD Diagnostics) and incubated at 25 °C in the dark. Pure cultures were obtained from individual conidia by recovering single spores. On PDA, colonies were initially white and cottony. The mycelia then became pinkish to deep-pink with time at the center on the front side and pink on the reverse side. Colonies produced pale orange conidial masses after 9 days. Conidia were fusiform with acute ends, smooth-walled, hyaline, and measured 3.6-5.5 × 8.1-14.5 µm (4.5 ± 0.5 × 10.6 ± 1.0 µm, n = 100). The morphological characteristics of the isolate matched the descriptions of Colletotrichum acutatum complex (Damm et al. 2012). For molecular identification, the internal transcribed spacer (ITS) region, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), chitin synthase (CHS-1), beta-tubulin 2 (TUB2), and actin (ACT) were sequenced using the primers ITS1/ITS4, GDF/GDR, CHS-79F/CHS-345R, T1/Bt2b, ACT-512F/ACT-783R, respectively (Weir et al. 2012). The obtained sequences were deposited into the GenBank [accession nos. MW584317 (ITS); MW656269 (GAPDH); MW656270 (TUB2); MW656268 (CHS-1); MW656267 (ACT)]. All the sequences showed 94 to 100% similarity with those of C. fioriniae. A neighbor-joining phylogenetic tree was generated by combining all the sequenced loci using MEGA7.0 (Kumar et al. 2016). The isolate TH-M4 clustered with C. fioriniae, having 99% bootstrap support. Base on the morphology and multi-gene phylogeny, isolate TH-M4 was identified as C. fioriniae (Damm et al. 2012). To confirm pathogenicity, 20 healthy leaves of 10 mu oil trees (3-year-old) grown outdoors were inoculated with a drop of spore suspension (106 conidia per mL) of the isolate TH-M4 in September 2020. Another 10 plants were inoculated with sterile water as the control. The leaves were wounded with a sterile toothpick. All the inoculated leaves were covered with black plastic bags to maintain humidity for 2 days. The pathogenicity test was repeated twice. The resulting symptoms were similar to those on the original infected plants, whereas the control leaves remained asymptomatic. The same fungus was re-isolated from the lesions on the inoculated plant, fulfilling Koch's postulates. C. fioriniae has been recorded as anthracnose pathogen on Mahonia aquifolium (Garibaldi et al. 2020), Paeonia lactiflora (Park et al. 2020), Solanum melongena (Xu et al. 2020), and Juglans regia (Varjas et al. 2020). To our knowledge, this is the first report of C. fioriniae associated with leaf spot disease on mu oil tree in China. This study provided crucial information for epidemiologic studies and appropriate control strategies for this oil plant disease.
ABSTRACT
Magnolia grandiflora (Southern magnolia) is a popular evergreen tree, planted especially as an ornamental for landscaping. In September 2019, leaf spots were observed on M. grandiflora at the campus of Jiangxi Agricultural University (28°45'56â³N, 115°50'21â³E). Approximately 64% (23 out of 36) M. grandiflora trees (most 24-year-old) occurred leaf spot disease at the campus. On average, 40% of the leaves per individual tree were affected. Foliar symptoms began as small dark brown lesions formed along the leaf margins. As the disease developed, the lesions' center was sunken with a dark brown border. Symptomatic leaves were collected and cut into 5 × 5 mm pieces. Leaf pieces from the margin of the necrotic tissue were surface sterilized in 70% ethanol for 30 s followed by 2% NaOCl for 1 min and then rinsed in sterile water three times. Tissues were placed on potato dextrose agar (PDA) and incubated at 25°C. Of more than 35 isolates, most shared a similar morphology, with an isolation rate of 85%. Three isolates (JNG-1, JNG-2, and JNG-3) were chosen for single-spore purification and used for morphological characterization and identification. Colonies on PDA of the three isolates were white, cottony, and grayish-white on the undersides of the culture. Conidia were single-celled, straight, hyaline, cylindrical, clavate, and measured 4.4-5.6 × 13.2-17.8 µm (4.7 ± 0.3 × 14.6 ± 1.0 µm, n = 100). Appressoria were brown to dark brown, ovoid to clavate, slightly irregular to irregular, and ranged from 5.5-9.2 × 4.6-6.5 µm (7.3 ± 0.4 × 5.4 ± 0.3 µm, n=100). Morphological features were similar to Colletotrichum siamense as previously described (Weir et al. 2012). The internal transcribed spacer (ITS) regions, actin (ACT), calmodulin (CAL), beta-tubulin 2 (TUB2), chitin synthase (CHS-1) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were amplified from genomic DNA for the three isolates using primers ITS1/ITS4, ACT-512F/ACT-783R, CL1/CL2, T1/Bt2b, CHS-79F/CHS-345R and GDF/GDR (Weir et al. 2012), respectively and sequenced. All sequences were deposited into GenBank (ITS, MZ325948-MZ325950; ACT, MZ461477 - MZ461479; GAPDH, MZ461483 - MZ461485; TUB2, MZ461486 - MZ461488; CHS-1, MZ441182 - MZ441184; CAL, MZ461480 - MZ461482). A neighbor-joining phylogenetic tree was constructed with MEGA 7.0 using the concatenation of multiple sequences (Kumar et al. 2016). According to the phylogenetic tree, all three isolates fall within the C. siamense clade (boot support 96%). The pathogenicity of three isolates were tested on M. grandiflora plants, which were grown in the field. Healthy leaves were wounded with a sterile needle and then inoculated with 10 µL of spore suspension (106 conidia/mL). Controls were treated with ddH2O (Zhu et al. 2019). All the inoculated leaves were covered with black plastic bags to keep a high-humidity environment for 2 days. All the inoculated leaves showed similar symptoms to those observed in field, whereas control leaves were asymptomatic for 10 days. The infection rate was 100%. C. siamense was re-isolated from the lesions, whereas no fungus was isolated from control leaves. It was confirmed that C. gloeosporioides is the causal agent of leaf spot on Magnolia virginiana in America (Xiao et al. 2004). However, this is the first report of C. siamense causing leaf spot on M. grandiflora in China. This study provided crucial information for epidemiologic studies and appropriate control strategies for this newly emerging disease.
ABSTRACT
Cornus hongkongensis (Hemsl.) is an excellent ornamental tree species in China and elsewhere. In 2019, C. hongkongensis anthracnose was firstly observed at the campus of Jiangxi Agricultural University (JXAU) (28°45'56â³N, 115°50'21â³E), then found in parks, Nanchang, China. In early August, the disease appeared and lasted until the leaves dropped (November). The disease incidence was above 60%, and the diseased leaf rate was above 70%. The lesions mostly appeared along the leaf edges. Some small round to irregular lesions also developed in other parts of the leaves. These diseased leaves had circular or irregularly shaped spots with gray-white color in the center and dark brown on the edge of the lesions. Later, the lesions became necrotic and shriveled. As the disease progressed, the spots coalesced so that affected leaves appeared blighted (Supplementary Figure 1 A-C). To identify the pathogen, leaves with typical symptoms from the campus of JXAU were collected and small pieces (5 × 5 mm) from the lesion borders were surfaced sterilized in 70% ethanol for 30 s, followed by 1 min in 3% NaOCl, and then rinsed with sterile distilled water three times. Leaf pieces were placed on potato dextrose agar (PDA) and incubated at 25 °C under a 12-h light/dark cycle (3000 lx). Pure cultures were obtained from individual conidia by single spore isolates. For studies of microscopic morphology, a representative isolate JX-S4 was subcultured on PDA. The colony of JX-S4 was white and turning gray and light gray on the reverse side, producing dark-green pigmentation near the center (Supplementary Figure 1 D). The conidia were one-celled, straight, hyaline, subcylindrical with rounded ends and 16.9 ± 1.6 × 6.0 ± 0.6 µm (n = 50) in size. Appressoria were one-celled, pale brown, thick-walled, ellipsoidal, and measured 8.7 ± 1.7 × 6.4 ± 0.8 µm (n = 50) (Supplementary Figure 1 E, F). The morphological characteristics of JX-S4 matched those of the Colletotrichum siamense species (Weir et al. 2012). For accurate identification, the internal transcribed spacer (ITS) and the genes encoding glyceraldehyde-3-phosphate dehydrogenase (GAPDH), chitin synthase (CHS-I), beta-tubulin 2 (TUB2), and calmodulin (CAL) were respectively amplified with primers ITS1/ITS4, GDF/GDR, CHS-79F/CHS-345R, ßt2a/ßt2b, and CL1/CL2. The sequences were deposited in GenBank (Accession nos. MT587807, MT628710, MT628709, MT628711, and MT628708). Phylogenetic analysis was calculated with concatenated sequences (ITS, GAPDH, CHS-I, CAL, and TUB2) using MEGA 7. In the maximum likelihood phylogenetic tree, Isolate JX-S4 was clustered with C. siamense with 93% bootstrap support (Supplementary Figure 2). Based on the morphological characteristics and phylogenetic analysis, JX-S4 was identified as C. siamense. Pathogenicity test of JX-S4 was verified on 45 attached healthy leaves from three C. hongkongensis plants (10-year-old) at the campus of JXAU inoculated with mycelial plugs (φ=5 mm) from the culture edge (6-day-old) on PDA. And an additional 45 healthy leaves were inoculated with PDA plugs as controls. The leaves were wounded with a red-hot needle (φ=0.5 mm). All treatment and control leaves were wrapped up with black plastic bags to keep them moist for 2 days. The pathogenicity tests were repeated twice. Within 7 days, all the inoculated leaves developed the lesions, which were similar to those observed in the field. Control leaves were asymptomatic (Supplementary Figure 1 G, H). The same fungus was re-isolated from the symptomatic tissues, fulfilling Koch's postulates. To our knowledge, this is the first report of C. siamense causing C. hongkongensis anthracnose. This finding provides crucial information for managing this disease. For example, when diagnosing Cornus anthracnose, C. siamense needs to be looked out for and appropriate control measures implemented.
ABSTRACT
Two yeast strains representing a novel species in the basidiomycetous yeast genus Naganishia were isolated from flowers of Sorbaria sorbifolia collected in Beijing Olympic Forest Park, PR China. Results of multi-gene phylogenetic analysis indicated that the two strains were closely related to the type strains of Naganishia bhutanensis (CBS 6294T) and Naganishia antarctica (CBS 7687T). However, the new isolates differed from N. bhutanensis CBS 6294T by 1.79â% sequence divergence in the D1/D2 domain (11 nt substitutions and three indels), and 2.42â% (15 nt differences and one indel) to N. antarctica CBS 7687T. In the ITS region, the new isolates showed 1.15â% divergence (7 nt substitutions and one indel) to N. bhutanensis CBS 6294T and 0.92â% divergence (5 nt substitutions and no indels) to N. antarctica CBS 7687T. A phylogenetic analysis employing the sequences of six genes (D1/D2 domain of large subunit rDNA, ITS, small subunit rDNA, two subunits of the RNA polymerase II and elongation factor-1α) indicated that the novel species belonged to the genus Naganishia and formed a well-supported clade with N. bhutanensis, N. antarctica and N. indica. Moreover, the two strains differed from their closest relatives by the ability to grow on distinct carbon and nitrogen sources and ability to grow at 30 °C. On the basis of these findings, we propose a novel species in the genus Naganishia (Filobasidiales), Naganishia floricola sp. nov. (holotype CGMCC 2.5856).
Subject(s)
Basidiomycota/classification , Flowers/microbiology , Phylogeny , Rosaceae/microbiology , Basidiomycota/isolation & purification , China , DNA, Fungal/genetics , DNA, Ribosomal Spacer/genetics , Mycological Typing Techniques , Sequence Analysis, DNAABSTRACT
Aspergillus sections Usti and Cavernicolarum are accommodated in the subgenus Nidulantes. In the present study, a polyphasic approach using morphology and multi-gene phylogeny was applied to investigate the taxonomy of these two sections. Based on the phylogenetic analysis, Aspergillus section Usti includes 25 species, which can be assigned to four series: Calidousti, Deflecti, Monodiorum and Usti. Aspergillus sigarelli is newly described in this section and this species was isolated from a cigarette from PR China and belongs to series Calidousti. It is clearly distinct from other members in this series based on ITS, BenA, CaM and RPB2 sequences. Aspergillus section Usti members like A. calidoustus and A. granulosus are important opportunistic pathogens, it is speculative that more pathogenetic species will be found by using polyphasic taxonomy approaches. Aspergillus section Cavernicolarum includes five species, the growth rates on agar media and size and ornamentation of conidia are important characters for differentiating species in section Cavernicolarum.
Subject(s)
Aspergillus/classification , Phylogeny , China , Sequence Analysis, DNA , Spores, FungalABSTRACT
Calonectria represents a genus of phytopathogenic ascomycetous fungi with a worldwide distribution. In recent years, there has been an increase in the number of taxonomic studies on these fungi. Currently, there are 169 described species of Calonectria based on comparisons of DNA sequence data, combined with morphological characteristics. However, for some of these species, the sequence data utilised at the time of their description were relatively limited. This has justified an urgent need to reconsider the species boundaries for Calonectria based on robust genus-wide phylogenetic analyses. In this study, we utilised 240 available isolates including the ex-types of 128 Calonectria species, and re-sequenced eight gene regions (act, cmdA, his3, ITS, LSU, rpb2, tef1 and tub2) for them. Sequences for 44 Calonectria species, for which cultures could not be obtained, were downloaded from GenBank. DNA sequence data of all the 169 Calonectria species were then used to determine their phylogenetic relationships. As a consequence, 51 species were reduced to synonymy, two new species were identified, and the name Ca. lauri was validated. This resulted in the acceptance of 120 clearly defined Calonectria spp. The overall data revealed that the genus includes 11 species complexes, distributed across the Prolate and Sphaero-Naviculate Groups known to divide Calonectria. The results also made it possible to develop a robust set of DNA barcodes for Calonectria spp. To accomplish this goal, we evaluated the outcomes of each of the eight candidate DNA barcodes for the genus, as well as for each of the 11 species complexes. No single gene region provided a clear identity for all Calonectria species. Sequences of the tef1 and tub2 genes were the most reliable markers; those for the cmdA, his3, rpb2 and act gene regions also provided a relatively effective resolution for Calonectria spp., while the ITS and LSU failed to produce useful barcodes for species discrimination. At the species complex level, results showed that the most informative barcodes were inconsistent, but that a combination of six candidate barcodes (tef1, tub2, cmdA, his3, rpb2 and act) provided stable and reliable resolution for all 11 species complexes. A six-gene combined phylogeny resolved all 120 Calonectria species, and revealed that tef1, tub2, cmdA, his3, rpb2 and act gene regions are effective DNA barcodes for Calonectria.
ABSTRACT
Species of Diaporthe (syn. Phomopsis) are important endophytes, saprobes and pathogens, infecting a wide range of plants and resulting in important crop diseases. However, the species occurring on pear remain largely unresolved. In this study, a total of 453 Diaporthe isolates were obtained from branches of Pyrus plants (including P. bretschneideri, P. communis, P. pyrifolia and P. ussuriensis collected from 12 provinces in China) showing shoot canker symptoms. Phylogenetic analyses based on five loci (ITS, TEF, CAL, HIS, and TUB) coupled with morphology of 113 representative isolates revealed that 19 Diaporthe species were isolated, representing 13 known species (including D. caryae, D. cercidis, D. citrichinensis, D. eres, D. fusicola, D. ganjae, D. hongkongensis, D. padina, D. pescicola, D. sojae, D. taoicola, D. unshiuensis and D. velutina) and six new species described here as D. acuta, D. chongqingensis, D. fulvicolor, D. parvae, D. spinosa and D. zaobaisu. Although Koch's postulates confirmed all species to be pathogenic, a high degree of variation in aggressiveness was observed. Moreover, these species have a high diversity, plasticity, and prevalence related to the geographical location and pear species involved.
ABSTRACT
The genus Thielavia is morphologically defined by having non-ostiolate ascomata with a thin peridium composed of textura epidermoidea, and smooth, single-celled, pigmented ascospores with one germ pore. Thielavia is typified with Th. basicola that grows in close association with a hyphomycete which was traditionally identified as Thielaviopsis basicola. Besides Th. basicola exhibiting the mycoparasitic nature, the majority of the described Thielavia species are from soil, and some have economic and ecological importance. Unfortunately, no living type material of Th. basicola exists, hindering a proper understanding of the classification of Thielavia. Therefore, Thielavia basicola was neotypified by material of a mycoparasite presenting the same ecology and morphology as described in the original description. We subsequently performed a multi-gene phylogenetic analyses (rpb2, tub2, ITS and LSU) to resolve the phylogenetic relationships of the species currently recognised in Thielavia. Our results demonstrate that Thielavia is highly polyphyletic, being related to three family-level lineages in two orders. The redefined genus Thielavia is restricted to its type species, Th. basicola, which belongs to the Ceratostomataceae (Melanosporales) and its host is demonstrated to be Berkeleyomyces rouxiae, one of the two species in the "Thielaviopsis basicola" species complex. The new family Podosporaceae is sister to the Chaetomiaceae in the Sordariales and accommodates the re-defined genera Podospora, Trangularia and Cladorrhinum, with the last genus including two former Thielavia species (Th. hyalocarpa and Th. intermedia). This family also includes the genetic model species Podospora anserina, which was combined in Triangularia (as Triangularia anserina). The remaining Thielavia species fall in ten unrelated clades in the Chaetomiaceae, leading to the proposal of nine new genera (Carteria, Chrysanthotrichum, Condenascus, Hyalosphaerella, Microthielavia, Parathielavia, Pseudothielavia, Stolonocarpus and Thermothielavioides). The genus Canariomyces is transferred from Microascaceae (Microascales) to Chaetomiaceae based on its type species Can. notabilis. Canariomyces is closely related to the human-pathogenic genus Madurella, and includes three thielavia-like species and one novel species. Three monotypic genera with a chaetomium-like morph (Brachychaeta, Chrysocorona and Floropilus) are introduced to better resolve the Chaetomiaceae and the thielavia-like species in the family. Chrysocorona lucknowensis and Brachychaeta variospora are closely related to Acrophialophora and three newly introduced genera containing thielavia-like species; Floropilus chiversii is closely related to the industrially important and thermophilic species Thermothielavioides terrestris (syn. Th. terrestris). This study shows that the thielavia-like morph is a homoplastic form that originates from several separate evolutionary events. Furthermore, our results provide new insights into the taxonomy of Sordariales and the polyphyletic Lasiosphaeriaceae.
ABSTRACT
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.
ABSTRACT
In our previous study, all Arthrinium isolates from Sargassum sp. showed high bioactivities, but studies on marine Arthrinium spp. are insufficient. In this study, a phylogenetic analysis of 28 Arthrinium isolates from seaweeds and egg masses of Arctoscopus japonicus was conducted using internal transcribed spacers, nuclear large subunit rDNA, ß-tubulin, and translation elongation factor region sequences, and their bioactivities were investigated. They were analyzed as 15 species, and 11 of them were found to be new species. Most of the extracts exhibited radical-scavenging activity, and some showed antifungal activities, tyrosinase inhibition, and quorum sensing inhibition. It was implied that marine algicolous Arthrinium spp. support the regulation of reactive oxygen species in symbiotic algae and protect against pathogens and bacterial biofilm formation. The antioxidant from Arthrinium sp. 10 KUC21332 was separated by bioassay-guided isolation and identified to be gentisyl alcohol, and the antioxidant of Arthrinium saccharicola KUC21221 was identical. These results demonstrate that many unexploited Arthrinium species still exist in marine environments and that they are a great source of bioactive compounds.
Subject(s)
Aquatic Organisms/metabolism , Biological Products/pharmacology , Seaweed/microbiology , Symbiosis , Xylariales/metabolism , Animals , Anti-Bacterial Agents/isolation & purification , Anti-Bacterial Agents/metabolism , Anti-Bacterial Agents/pharmacology , Antifungal Agents/isolation & purification , Antifungal Agents/metabolism , Antifungal Agents/pharmacology , Antioxidants/isolation & purification , Antioxidants/metabolism , Antioxidants/pharmacology , Aquatic Organisms/genetics , Biofilms/drug effects , Biological Assay/methods , Biological Products/isolation & purification , Biological Products/metabolism , Chromobacterium/drug effects , DNA, Fungal/genetics , DNA, Fungal/isolation & purification , Enzyme Inhibitors/isolation & purification , Enzyme Inhibitors/metabolism , Enzyme Inhibitors/pharmacology , Monophenol Monooxygenase/antagonists & inhibitors , Oocytes/microbiology , Perciformes/microbiology , Phylogeny , Quorum Sensing/drug effects , Xylariales/geneticsABSTRACT
In 2007 a new Stemphylium leaf spot disease of Beta vulgaris (sugar beet) spread through the Netherlands. Attempts to identify this destructive Stemphylium sp. in sugar beet led to a phylogenetic revision of the genus. The name Stemphylium has been recommended for use over that of its sexual morph, Pleospora, which is polyphyletic. Stemphylium forms a well-defined monophyletic genus in the Pleosporaceae, Pleosporales (Dothideomycetes), but lacks an up-to-date phylogeny. To address this issue, the internal transcribed spacer 1 and 2 and intervening 5.8S nr DNA (ITS) of all available Stemphylium and Pleospora isolates from the CBS culture collection of the Westerdijk Institute (N = 418), and from 23 freshly collected isolates obtained from sugar beet and related hosts, were sequenced to construct an overview phylogeny (N = 350). Based on their phylogenetic informativeness, parts of the protein-coding genes calmodulin and glyceraldehyde-3-phosphate dehydrogenase were also sequenced for a subset of isolates (N = 149). This resulted in a multi-gene phylogeny of the genus Stemphylium containing 28 species-clades, of which five were found to represent new species. The majority of the sugar beet isolates, including isolates from the Netherlands, Germany and the UK, clustered together in a species clade for which the name S. beticola was recently proposed. Morphological studies were performed to describe the new species. Twenty-two names were reduced to synonymy, and two new combinations proposed. Three epitypes, one lectotype and two neotypes were also designated in order to create a uniform taxonomy for Stemphylium.
ABSTRACT
Aspergillus section Aspergillus (formerly the genus Eurotium) includes xerophilic species with uniseriate conidiophores, globose to subglobose vesicles, green conidia and yellow, thin walled eurotium-like ascomata with hyaline, lenticular ascospores. In the present study, a polyphasic approach using morphological characters, extrolites, physiological characters and phylogeny was applied to investigate the taxonomy of this section. Over 500 strains from various culture collections and new isolates obtained from indoor environments and a wide range of substrates all over the world were identified using calmodulin gene sequencing. Of these, 163 isolates were subjected to molecular phylogenetic analyses using sequences of ITS rDNA, partial ß-tubulin (BenA), calmodulin (CaM) and RNA polymerase II second largest subunit (RPB2) genes. Colony characteristics were documented on eight cultivation media, growth parameters at three incubation temperatures were recorded and micromorphology was examined using light microscopy as well as scanning electron microscopy to illustrate and characterize each species. Many specific extrolites were extracted and identified from cultures, including echinulins, epiheveadrides, auroglaucins and anthraquinone bisanthrons, and to be consistent in strains of nearly all species. Other extrolites are species-specific, and thus valuable for identification. Several extrolites show antioxidant effects, which may be nutritionally beneficial in food and beverages. Important mycotoxins in the strict sense, such as sterigmatocystin, aflatoxins, ochratoxins, citrinin were not detected despite previous reports on their production in this section. Adopting a polyphasic approach, 31 species are recognized, including nine new species. ITS is highly conserved in this section and does not distinguish species. All species can be differentiated using CaM or RPB2 sequences. For BenA, Aspergillus brunneus and A. niveoglaucus share identical sequences. Ascospores and conidia morphology, growth rates at different temperatures are most useful characters for phenotypic species identification.