Species Of Glomerella Research Articles

First Report of a Leaf Anthracnose on Rohdea japonica (Japanese Sacred Lily) Caused by Colletotrichum liriopes (Glomerella Species) in the United States.

HomePlant DiseaseVol. 102, No. 11First Report of a Leaf Anthracnose on Rohdea japonica (Japanese Sacred Lily) Caused by Colletotrichum liriopes (Glomerella Species) in the United States PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of a Leaf Anthracnose on Rohdea japonica (Japanese Sacred Lily) Caused by Colletotrichum liriopes (Glomerella Species) in the United StatesR. N. Trigiano, S. L. Boggess, E. C. Bernard, and A. S. WindhamR. N. Trigiano†Corresponding author: R. N. Trigiano; E-mail: E-mail Address: rtrigian@utk.eduhttp://orcid.org/0000-0002-7264-1822Search for more papers by this author, S. L. BoggessSearch for more papers by this author, E. C. BernardSearch for more papers by this author, and A. S. WindhamSearch for more papers by this authorAffiliationsAuthors and Affiliations R. N. Trigiano † S. L. Boggess E. C. Bernard , Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, 37996-4560 A. S. Windham , Department of Entomology and Plant Pathology, University of Tennessee, Nashville, 37211. Published Online:24 Aug 2018https://doi.org/10.1094/PDIS-03-18-0388-PDNAboutSectionsSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Rohdea japonica (Asparagaceae: Japanese sacred lily) is an ornamental garden plant in the United States but is native to eastern Asia. The species is typically evergreen in warm growing areas but can be deciduous in colder climates, has inconspicuous flowers, and produces bright red berries that are persistent in winter. In May of 2016 and 2017, anthracnose-like, circular lesions with red borders surrounded by chlorotic tissues were observed on leaves of R. japonica at the University of Tennessee, Knoxville. Signs included numerous cushion-like, dark acervuli with prominent, long, black setae formed on necrotic tissue. Conidia were single celled, colorless, fusiform to linear, and had a mean (n = 20) length of 24.8 µm (21.3 to 27.3 µm) and a mean width of 4.4 µm (4.0 to 5.1 µm). The description of the disease and the fungus agreed well with the reports of Colletotrichum liriopes infecting R. japonica (Kwon and Kim 2013) and Liriope muscari (Oo and Oh 2017) in Korea, except the conidia in these reports were slightly narrower. A similar disease of R. japonica caused by a Colletotrichum sp. was reported from California (French 1989). Lesions with a border of healthy tissue were excised and dipped in 70% ethanol for 30 s, immersed in 1.3% NaOCl for 10 min, and rinsed three times in sterile water. Tissues from the margin of lesions were transferred to half-strength potato dextrose agar augmented with 10 mg of rifampicin/liter and incubated in the dark. Two colony morphotypes were apparent after 1 week: a dark, black, flocculent mycelium with conidiomata and conidia, without setae, and a light brown, appressed slimy mycelium with numerous red-brown perithecia formed on orange-pigmented mycelium. The eight ascospores/ascus had a mean (n = 20) length of 18.5 µm (14.4 to 20.8 µm) and a mean width of 6.8 µm (5.8 to 7.6 µm). A Glomerella sp. sexual stage is often associated with Colletotrichum spp., but none has been reported for C. liriopes (Réblová et al. 2011). Sclerotia (Kwon and Kim 2013; Oo and Oh 2017) were not observed in our cultures. DNA was extracted from both colony morphotypes and amplified with ITS1-S4 primers (White et al. 1990), and the amplicons were sequenced. Sequences from both colony morphotypes were identical (MH005034) and aligned perfectly with GenBank accession HM585396 for C. liriopes. Sequences for five other C. liriopes entries in GenBank were the same as our sequence except there was a single nucleotide variant (C to A) at bp 494. Leaves of 10 plants were sprayed with a 1 × 105 conidia/ml suspension to runoff, and 10 control plants with sterile water. Plants in containers were placed in plastic bags and maintained in high humidity at room temperature for 2 days and then grown for 28 days exposed to natural light in our lab. Anthracnose symptoms appeared after 10 to 14 days and were identical to the original disease profile; control plants were symptomless. Only the dark black mycelium was reisolated from lesions. We concluded that the disease on R. japonica was caused by C. liriopes. The disease did not kill plants in Tennessee but did affect their aesthetic quality, and therefore, control measures should be developed and employed.

First Report of Fruit Stem Anthracnose of Kiwifruit Caused by Glomerella septospora in China.

Kiwifruit (Actinidia spp.) is a very economically important fruit crop in southern China, namely Fengxin County. In 2011 and 2012, a new anthracnose on the fruit stem of kiwifruit with blight symptoms was observed during the blossom and fruit-set periods. This caused considerable blossom and fruit drop. To isolate the causal pathogen, symptomatic fruit-stem tissue at the junction of diseased and healthy tissue was cut into 30-mm-long segments. The segments were surface-sterilized in 70% ethanol solution for 10 s, followed by 0.1% mercuric chloride solution for 3 min, and a final set of three rinses in sterile distilled water. Segments were plated onto PDA and incubated at 25°C on a 12-h alternating light-dark cycle (1). Colonies emerging from plant tissues were then transferred to new PDA plates to obtain pure cultures. Colonies grew at the rate of 13.75 mm/day, and were initially white, then became dark green. After 25 days incubation, black and subglobose perithecia appeared at the center of the colonies. Through microscopic examination of perithecia at 400× magnification, club-shaped asci, usually containing 8 ascospores, were found. Ascospores were cylindrical to narrowly fusiform, straight or slightly curved, mostly 3-septate, and 54.5 to 107.5 × 5.0 to 7.5 μm in size. Combining cultural and morphological characteristics with reports in the literature (2), the pathogen was preliminarily identified as a Glomerella species. For six isolates, the rDNA internal transcribed spacer (ITS) region was amplified with the primers ITS1 and ITS4, and the sequences were deposited in GenBank (JX885687). A BLASTn search of GenBank showed that the ITS sequence of our Glomeralla isolate (JX885687) had 100% homology with that of an isolate of Glomeralla septospora (GU935911). Twenty representative isolates (G. septospora) obtained from infected fruit stem tissues in the blossom period and the fruit-set period, respectively, were selected for pathogenicity tests on detached young fruit stems of kiwifruit (JinKui). Each isolate was inoculated into three fruit stems, each of which was slightly wounded with a sterile scalpel and inoculated with a 5-mm-diameter colonized potato dextrose agar (PDA) plug. Negative control stems were treated with the sterile PDA plugs. The inoculated stems were incubated in a growth chamber at 25°C and 95% relatively humidity. After 4 days, characteristic symptoms of fruit stem anthracnose were observed on all inoculated stems, whereas the controls remained asymptomatic. Pure cultures of G. septospora were recovered from all inoculated fruit stems, fulfilling Koch's postulates. These results showed G. septospora is the pathogen of fruit stem anthracnose of kiwifruit, and to our knowledge, this is the first report of G. septospora causing fruit stem anthracnose of kiwifruit in Fengxin county, Jiangxi Province of China, as well as in the world.

Glomerella truncata: another Glomerella species with an atypical mating system

In the genus Glomerella all species studied to date do not fit the usual mating system of heterothallic ascomycetes. This study investigated the mating system of G. truncata (anamorph Colletotrichum truncatum), a pathogen responsible for lentil anthracnose. Twenty-two field isolates from the Canadian prairies were crossed in all possible combinations, including selfings. All isolates also were screened for the presence of the MAT1-1 and MAT1-2 idiomorphs by targeting small conserved areas of the MAT genes (the alpha domain and the high mobility group HMG box) with degenerate primers, and a pair of G. truncata-specific HMG primers (CT21HMG) were designed. The results of the classical mating study suggested that G. truncata is heterothallic. Isolates fell into two incompatibility groups, which is consistent with a bipolar mating system but different from what has been described in other Glomerella species. Molecular screening showed that the HMG box used as a marker for the MAT1-2 idiomorph was present in both partners of fertile crosses in G. truncata, unlike in the typical ascomycete system, but as previously described for two other Glomerella species. G. truncata therefore appears to share unusual mating system characteristics with the other Glomerella species studied to date.

First Report of Anthracnose Caused by Glomerella acutata on Chili Pepper in China.

A new anthracnose disease on chili pepper (cayenne pepper cv. Hongxiu 2003, fruiting type pepper) was found in Zhijiang County, Hunan, China in 2009. The disease was observed only on the fruits. Lesions were generally elongated, on which dark acervuli were arranged concentrically. Later, cracking of older lesions was observed. With a microscope, fungal conidia were observed to be 15.8 × 4.1 μm, fusiform or oval with one end acute, and single celled with two to seven oil globules. No setae were found on the acervuli. Eight isolates (HNZJ001-HNZJ008) showed no difference in colony feature when cultured on potato dextrose agar. All the isolates showed white growth at the early stages, but colonies turned pink when they produced powdery spores and then finally became red gray. The average colony diameter was 68.5 to 72.3 mm after 7 days with obvious gray black concentric rings because of the development of aerial and substrate mycelia. After a needle-prick inoculation with a suspension of 1 × 106 spores per ml of HNZJ001 on 30 chili pepper fruits with three repeats, the same symptoms were observed and the same fungus was recovered. In bioassays, HNZJ001 caused lesions on both mature and immature fruits, while Glomerella cingulata strain LSQ1 (GenBank Accession No. HQ607386) used as a control did not infect immature fruits. PCR amplification was carried out by utilizing universal rDNA-ITS primer pair ITS4/ITS5. Sequencing of the PCR products of HNZJ001 (GenBank Accession No. GU059863) showed 100% identity to G. acutata (GenBank Accession No. EU008863) and Colletotrichum acutatum (GenBank Accession No. AF207794) after a BLAST search. The pathogen was identified as G. acutata (asexual stage: C. acutatum) on the basis of morphological characters and rDNA-ITS sequence analysis. Worldwide, it has been reported that pepper anthracnose might be caused by up to five species of Glomerella (Colletotrichum): G. cingulata, C. coccodes, C. capsici, C. dematium, and G. acutata (2), among which only the first three were previously reported in China. In recent years, G. acutata was reported on such plants as apple (3) and strawberry (1) in China, but not on pepper. To our knowledge, this is the first report of G. acutata on chili pepper in China.

A Glomerella species phylogenetically related to Colletotrichum acutatum on Norway maple in Massachusetts

A fungus isolated from Norway maple (Acer platanoides) in the Boston, Massachusetts, area was determined to be a species of Glomerella, the teleomorph of Colletotrichum acutatum. Pure cultures of the fungus were obtained from discharged ascospores from perithecia in leaf tissue. This fungus was determined to be homothallic based on the observation of perithecial development in cultures of single-spore isolates grown on minimal salts media and with sterile toothpicks. A morphological and molecular analysis was conducted to determine the taxonomic position of this fungus. Parsimony analyses of a combined nucleotide dataset of the ITS and LSU rDNA region, and of the D1–D2 LSU rDNA region, indicated that this species has phylogenetic affinities with Colletotrichum acutatum, C. acutatum f. sp. pineum, C. lupini, C. phormii and G. miyabeana. These results are significant because C. acutatum has not been reported on Acer platanoides. In addition the consistent presence of perithecia on leaf tissue and in culture is unusual for Colletotrichum, suggesting that the teleomorphic state is important in the life cycle of this fungus.

Heterothallic mating observed between Mexican isolates of Glomerella lindemuthiana

Although several reports have described the occurrence of the teleomorphic state of Glomerella lindemuthiana (anamorph, Colletotrichum lindemuthianum), there has been a lack of continuity in this research. To identify G. lindemuthiana isolates capable of developing the teleomorphic state, 19 Mexican isolates were analyzed. Three types of response were observed: (i) negative, where only mycelial growth with or without acervuli was observed; (ii) potential, where in addition to the above, spherical perithecia-like structures were observed; (iii) positive, where perithecia containing asci and ascospores were observed. All strains were self-sterile and only one combination of strains produced fertile perithecia. From this fertile combination 168 individual ascospore cultures were isolated, including five from a single ascus. Forty-four monoascospore cultures were characterized with AFLP, confirming that these individuals were progeny from a sexual cross between the original two G. lindemuthiana isolates and that sexual reproduction in G. lindemuthiana is heterothallic in nature. Analysis of the parental strains with degenerate PCR primers indicated that sequences homologous to the HMG box of the MAT1-2 idiomorph are present in both parental isolates. This supports previous observations in other Glomerella species where the standard ascomycete configuration of distinct idiomorphs at the MAT locus does not hold true. The significance of these results is discussed.

Heterothallic mating observed between Mexican isolates of Glomerella lindemuthiana

Although several reports have described the occurrence of the teleomorphic state of Glomerella lindemuthiana (anamorph, Colletotrichum lindemuthianum), there has been a lack of continuity in this research. To identify G. lindemuthiana isolates capable of developing the teleomorphic state, 19 Mexican isolates were analyzed. Three types of response were observed: (i) negative, where only mycelial growth with or without acervuli was observed; (ii) potential, where in addition to the above, spherical perithecia-like structures were observed; (iii) positive, where perithecia containing asci and ascospores were observed. All strains were self-sterile and only one combination of strains produced fertile perithecia. From this fertile combination 168 individual ascospore cultures were isolated, including five from a single ascus. Forty-four monoascospore cultures were characterized with AFLP, confirming that these individuals were progeny from a sexual cross between the original two G. lindemuthiana isolates and that sexual reproduction in G. lindemuthiana is heterothallic in nature. Analysis of the parental strains with degenerate PCR primers indicated that sequences homologous to the HMG box of the MAT1-2 idiomorph are present in both parental isolates. This supports previous observations in other Glomerella species where the standard ascomycete configuration of distinct idiomorphs at the MAT locus does not hold true. The significance of these results is discussed.

Molecular systematics of the Phyllachorales (ascomycota, fungi) based on 18S ribosomal DNA sequences

In order to evaluate the monophyly of the Phyllachorales from a molecular standpoint and elucidate its phylogenetic relationships with other orders, a segment of the 18S rRNA gene from several representatives of the Phyllachorales, including species of Glomerella, Phyllachora, Coccodiella (=Coccostroma), Sphaerodothis, Ophiodothella, as well as Magnaporthe was sequenced. Maximum Parsimony analysis revealed that the Phyllachorales was a polyphyletic assemblage of taxa. None of the other members of the Phyllachorales, which produced either a clypeus or stroma, clustered with Glomerella. Of the taxa examined, was Coccodiella the closest relative of Phyllachora. Magnaporthe was closely related to the Diaporthales. Our 18S rDNA data highly supported Glomerella being accommodated in a separate family.

Fungi associated with leaf spots of palms in north Queensland, Australia

Twenty-six fungi associated with leaf spots of palms in north Queensland have been identified, including 12 ascomycetes, one basidiomycete and 13 deuteromycetes. Eight were identified as species new to science. A new species of Pseudospiropes is described and descriptions of two unnamed species of Glomerella are also given.

The role of mannan-degrading enzymes in the lysis of some plant pathogenic filamentous fungi, Glomerella species.

The role of mannan-degrading enzymes in the lysis of some plant pathogenic filamentous fungi, Glomerella species.

Spore discharge in Glomerella

A species of Glomerella grown under controlled conditions discharged spores in a brief span during the first hour of darkness. Dark periods as brief as 5 min during the photoperiod also elicited release within 30 min. A temperature drop of 5·5 and 11 °C but not 3° resulted in discharge; increasing the temperature 5·5 from 21° had no effect but release occurred when temperature returned to 21°. A drop in humidity also caused immediate discharge. There was no evidence of an endogenous pattern in continuous light or continuous dark.

Observations on the Sexual Stage of Colletotrichum orbiculare

An isolate of the fungus Colletotrichum orbiculare (syn. C. lagenarium) race 1 that forms perithecia in culture was isolated from edible gourd in North Carolina. This isolate has been identified as a species of Glomerella. The isolate produces very few ascopores when selfed; however, ascospores are produced in abundance when mated with certain other isolates of C. orbiculare.

Studies on the perfect stage of the causal fungus of the anthracnose of cucumber

The writers found the ascigerous stage of the cucumber anthracnose fungus, Colletotrichum lagenarium (PASS.) ELLIS et HALSTED, in a potato agar culture in March 1949. Morphological examinations proved the fungus to be included in the genus. Glomerella.The amount of production of ascospore was scarcely effected by temperature, but the rate of ascosporic production was delayed under higher temperature (25-30°C) than under lower temperature (20-15°C). The fungus produced ascospores more copiously and rapidly in potato-decoction and potato-decoction-agar cultures, compared with cultures on other kinds of media.The fungus differs in important respects from previously described species of Glomerella, especially from the bean anthracnose fungus, Glomerella Lindemuthianum (SACC. et MAG.) SHEAR and is here designated a new species.Glomerella lagenaria (PASS.) WATANABE et TAMURA, nov. sp. Perithecia spherical, subspherical or pyriform, membraneous, immersed in a stroma, dark-brown, 112-256μ in diameter; asci sessile, clavate or cylindrical, hyaline, 47.5-77.5μ in length and 7.5-11.25μ in width; ascospores 8, hyaline, oblong, slightly curved or straight, elliptical or fusoid, 1-celled, 12.5-27.5μ in length and 3.75-6.25μ in width; paraphyses none.Conidial stage: Colletotrichum lagenarium (PASS.) ELLIS et HALSTED in Bull. Torrey Bot. Club, Vol. 20, pp.109-112, 1893.

A new species of Glomerella on Camellia theae

A new species of Glomerella on Camellia theae

Shear's Studies of Parasitic Species of Glomerella

Shear's Studies of Parasitic Species of Glomerella