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1.
Plant Dis ; 2022 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-36044368

RESUMEN

Phyllostachys aureosulcata McClure 'Spectabilis' C.D. Chu. et C.S. Chao is predominantly native to subtropical to warm temperate areas and is widely cultivated for landscaping in China (Neményi et al. 2015). In November 2020 (10 - 16 ℃), culm blight symptoms were observed on P. aureosulcata 'Spectabilis' in Wangjiang Tower Park (all kinds of plant areas are about 9.8 ha), Chengdu City (104°09'30.42″ E, 30°63'18.89″ N). Fifty plants were surveyed, and disease incidence was recorded as approximately 30%. Initially, chlorotic necrotic patches appeared on the culms, and gradually the patches became white, expanded to both ends, and encircled the whole culm with black edge and conidiomata, which eventually led to wilt and death. Five samples from different bamboos were collected and one of them were used for morphological observation. Five single conidia isolates were carried out on potato dextrose agar (PDA) at 25±1℃ (Chomnunti et al. 2014). Colonies were initially white and then yellowish in the center with abundant aerial mycelia. On the culm, conidiomata were dry, black, and filamentous. Conidiophores were reduced to conidiogenous cells. Conidiogenous cells were smooth, hyaline, ampulliform to doliiform. Conidia were ellipsoid to globose, dark brown, smooth and aseptate, measuring 5.2 to 9.4 × 4.4 to 7.3 µm, (=8.2 × 6.5µm, n=50). On the PDA medium, conidia were globose to subglobose, olive green to pale brown, and smooth, larger than those from the host in size, measuring 9.0 to 18 × 7.5 to 9.5 µm ( =36.6 × 18.8 µm, n=50). These asexual structures were extremely similar to Apiospora locuta-pollinis (F. Liu & L. Cai) X.G. Tian & Tibpromma (Zhao et al. 2018). DNA was extracted from the representative strain (SICAUCC 22-0036), and the internal transcribed spacer (ITS), translation elongation factor 1-alpha (tef1-α), beta-tubulin (tub2), 28S large subunit rDNA (LSU) were amplified and sequenced with primers ITS1/ITS4 (White et al. 1990), EF1-728F (Carbone & Kohn 1999)/EF2 (O'Donnell et al. 1998), T1 (O'Donnell & Cigelnik 1997)/Bt2b (Glass & Donaldson 1995) and LR0R/LR5 (Rehner & Samuels 1994). The newly generated sequences were deposited in GenBank with accession nos. ON228609 (ITS), ON324018 (tef1-α), ON237657 (tub2), and ON228665 (LSU). Nucleotide blast showed 98.97%, 100% and 99.46% identities with A. locuta-pollinis (LC11683, ex-holotype) (accession nos. MF939595, MF939622, MF939616), and LSU data missing. Phylogenetic analyses using maximum likelihood showed a 92% bootstrap support value in a clade with A. locuta-pollinis (Fig 2). Eight healthy plants (2-year-old) were used for the pathogenicity test. Culms of four healthy bamboos were wounded via sterile double-edged blade and sprayed with conidial suspension (105 conidia/ml) prepared from 4-week-old cultures that were incubated on PDA at 25℃. The other four bamboos were sprayed with sterile distilled water as controls. Inoculated plants were placed in a growth chamber (25℃, 90% relative humidity, 12-h photoperiod). About 60 days later, necrotic patches similar to those observed in the field were found on the inoculated culms, and no symptoms were observed on the controls. The pathogen was reisolated from the diseased culms with identical morphology as previously described. To our knowledge, this is the first report of culm blight on P. aureosulcata 'Spectabilis' caused by A. locuta-pollinis. The risk of this pathogen needs further evaluation, and effective control measures should be taken.

2.
Plant Dis ; 2022 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-35350888

RESUMEN

Juglans regia L. is one of the major cultivated walnut species in China for nuts and wood (Pollegioni et al. 2012). In June 2020, branches with blight symptoms were observed in an orchard at Chongzhou City (30°33'34″N, 103°38'35″E). In an orchard of 30 hectares, disease incidence was around 50%. A total of 15 plants were sampled and 40% of their branches were affected by this disease. Firstly, brown and irregular spots appeared, then the spots gradually expanded and encircled the branch, which eventually killed the branch. Five samples of diseased branches from different trees were collected and a single fungal isolate was obtained from each of the five samples using the single ascospore isolation (Chomnunti et al. 2014). Colonies of the five isolates on potato dextrose agar (PDA) were identical that initially appeared white on the top, becoming light to dark brown with age. On the host, ascostroma were black, globose to subglobose, short-papillate, ostiolate, 260 - 410 × 210 - 320 µm (x = 335 × 265 µm, n = 20). Asci were 8-spored, bitunicate, cylindrical, short pedicellate, 55 - 78 × 8 - 12 µm (x = 67.5 × 10 µm, n = 40). Ascospores were 1-septate, fusiform to ellipsoidal, slightly curved, guttulate, 12 - 17 × 3 - 5 µm (x = 14.5 × 4 µm, n = 40). These sexual morphological characteristics are consistent with the Palmiascoma qujingense Phook. & K.D. Hyde (Monkai et al. 2021). Asexual morphs were formed on PDA in incubator after 17 days (25℃, 90% relative humidity, 12-h photoperiod). Conidiomata were black, globose to subglobose, 220 - 300 × 240 - 380 µm (x = 270 × 310 µm, n = 20). Conidia were oblong to ellipsoidal, aseptate and smooth-walled, 3 - 7 × 2 - 4 µm (x = 4.9 × 3 µm, n = 50). The genomic DNA of a representative isolate SICAUCC 21-0013 was extracted, and the internal transcribed spacers (ITS) region, large subunit rDNA (LSU) region, small subunit rDNA (SSU) region, and the largest subunit of RNA polymerase II (rpb2) gene were amplified and sequenced with primers ITS5/ITS4 (White et al. 1990), LR0R/LR5 (Rehner et al. 1994), NS1/NS4 (White et al. 1990), and fRPB2-5F/fRPB2-7cR (Liu et al. 1999), respectively. The sequences were deposited in NCBI with accession numbers MZ983549, MZ959419, MZ951112, and MZ818772, respectively, which showed 100%, 100%, 99.14%, and 99.59% identities with P. qujingense KUMCC 19-0201 (holotype) (accession numbers MT477185, MT477186, MT477183, MT495782respectively). Phylogenetic analysis (maximum likelihood) based on a concatenated dataset showed 93% bootstrap support values with P. qujingense. To verify Koch's postulates, 9 healthy branches from three 1-year-old seedlings were inoculated with conidial suspension (106 conidia/ml) from 4-week-old cultures via pin-prick inoculation (Desai et al. 2019), and the same number of seedlings and branches were inoculated with sterile water as controls. Plants were placed in a greenhouse at 25℃ and 90% RH on a 12-h fluorescent light/dark regime. After 28 days, brown spots were formed on P. qujingense-inoculated branches and similar to those observed in the field, while the controls remained asymptomatic. The pathogen was re-isolated from the lesions and identified by morphology and phylogeny. To our knowledge, this is the first report of P. qujingense causing branch blight on J. regia in the world. This disease potentially impacts the growth and yield of J. regia, and control measures should be made.

3.
Plant Dis ; 2021 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-34213970

RESUMEN

Magnolia coco (Lour.) DC. is an ornamental shrub and widely cultivated in southern China (Nana et al. 2017). In April 2020, leaf blight symptoms were observed on the leaves of M. coco in the Chengdu campus of Sichuan Agricultural University (30°42'19.92″N, 103°51'30.61″E, 493 m) where didn't have great protection, with roughly 70% leaves per plant were diseased. The initial symptoms presented on the leaf apex, which was manifested as dark brown spots surrounded with obvious yellowish halo (Fig. 1). As the disease progressed, spots gradually enlarged and coalesced covering the leaf, and severe infection finally caused leaf necrosis and plant decline. Four specimens from different diseased plants were used for pathogen isolation and morphological observation. Four fungal isolates were obtained from four specimens, following Chomnunti et al. (2014). Colonies on potato dextrose agar (PDA) medium were initially white and then light brown to dark brown. Pycnidia measured 284-427 × 326-554 µm (x=372.8 µm × 476.1 µm, n=20), and were brownish-black to black, broadly globose to irregular. The pycnidial wall measured 16-27 µm wide (n=20) and was composed of hyaline to brown cells of textura angularis. Conidiophores were absent, and the conidiogenous cells are pear-shaped, colorless, and smooth. Conidia measured 5-8 × 4-6 µm (x=6.5 µm × 4.6 µm, n=50), and were elliptical or subglobose, thick-walled, aseptate, hyaline, smooth, brown. These asexual structures were similar to Nothophoma quercina (Syd. & P. Syd.) Qian Chen & L. Cai described by Chen et al. (2017). The genomic DNA of representative isolate SICAUCC 21-0011 was extracted, and the internal transcribed spacers (ITS), 28S large subunit rDNA (LSU), RNA polymerase II large subunit 2 (RPB2), and beta-tubulin (TUB2) regions were amplified using the primer pairs ITS5/ITS4, LR0R/LR5, FRPB2-5F/FRPB2-7cR, and T1/BT4R, respectively. The accession numbers deposited in GenBank were MW541930 (ITS), MW541934 (LSU), MW883395 (RPB2), and MW883394 (TUB2). Nucleotide BLAST showed high homology with the sequences of N. quercina, viz. GU237900 (ITS, 485/486, 99.79%), EU754127 (LSU, 862/862, 100%), KT389657 (RPB2, 593/596, 99.49%), and GU237609 (TUB2, 333/335, 99.40%). Phylogenetic analyses based on a combined dataset showed 100% bootstrap support values in a clade with N. quercina complexes (Fig. 2). Four healthy potted plants (2-years-old) with 15 to 20 leaves per plant were sprayed with conidial suspension (105 conidia/mL) prepared from 4-week-old cultures of SICAUCC 21-0011, which incubated on PDA at 25℃, onto the wounded sites via pin-prick inoculation described by Desai et al. (2019). Another four plants were sprayed with sterilely distilled water as controls. Inoculated plants were cultured in a growth chamber (25℃, 95% relative humidity, and 12-h photoperiod). About 30 days later, brown spots were found on the inoculated leaves, which were similar to those observed in the field. There were no symptoms on the control plants, and the pathogen was re-isolated from the diseased leaves and characterized morphologically. N. quercina has been reported on Photinia × fraseri Dress, Aucuba japonica, Malus micromalus, and Chaenomeles sinensis (Mohamed et al. 2019, Lv et al. 2020, Zou et al. 2021). To our knowledge, this is the first report of leaf blight on M. coco caused by N. quercina. M. coco is one of the important ornaments in the courtyard, street, and park in China, and the risk of this pathogen needs further exploration and effective control measures should be made. Qian Zeng, Yicong Lv, and Xinyue Li contributed equally to this work.

4.
Plant Dis ; 2021 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-34096768

RESUMEN

"Chuanzao 2" is a walnut variety derived from the hybridization of Juglans regia L. and J. sigillata Dode distributed in southwest China, where it is an economically important tree species in rural regions (Xiao et al. 2012). In April 2020, the variety in a walnut garden showed symptoms of brown leaf spot in Beishan Town (107°21'43.93″E, 31°28'12.34″N), Dazhou City in Sichuan, China, with 5% to 10% of leaves per plant affected (5 plants). Symptomatic leaves showed brown to dark brown spots (2 to 5 mm) with a dark brown to black halo and grayish-tan center. The spots were subcircular to irregular in shape, and gradually expanded and formed necrotic spots. A single conidium isolation was performed (Senanayake et al. 2020) and transferred to Potato Dextrose Agar (PDA). Five isolates were obtained from five different infected leaves. Colonies of five isolates were subcircular, erose or dentate, flat or effuse, white initially, gradually becoming yellowish with white margins, developed and fluffy aerial mycelia, and conidiogenensis was produced underneath mycelia after 25-days-incubation. Conidiogenous cells were subcylindrical to cylindrical, or irregular in shape, and hyaline. Macroconidia were lunate, reniform, hyaline, basal cell bluntly rounded, apical cell with acute end, 1-septate, rarely aseptate, sometimes slightly constricted at septum, basal cell equal or larger than apical cell, and measured 16.5 to 30.5 × 5 to 8.5 µm (mean = 23.2 × 6.3 µm, n = 50). Microconidia were not observed. These morphological characteristics resembled those of Ophiognomonia leptostyla (Fr.) Sogonov (Walker et al. 2012a). For molecular identification, genomic DNA (isolates SICAUCC 21-0008 and SICAUCC 21-0010) was extracted, and the internal transcribed spacers (ITS) region, guanine nucleotide-binding protein subunit beta (MS204) gene, and translation elongation factor 1-alpha (tef1-α) were amplified and sequenced by using the primers ITS5/ITS4 (White et al. 1990), E1F1/E5R1a (Walker et al. 2012a), and EF1-728F/EF1-1567R (Walker et al. 2012b), respectively. Phylogenetic analyses (maximum likelihood) based on a combined dataset showed 100% bootstrap support values in a clade with O. leptostyla. The sequences of ITS, MS204, and tef1-α genes were deposited in GenBank with accession numbers MW493111/MZ026300, MW495270/MZ031975, and MW495271/MZ031974, respectively. To fulfill Koch's postulates, five healthy hybrid plants (2 to 3 years old) with 5 to 8 leaves per plant were spray inoculated with conidium suspensions (104 conidia/mL; isolate SICAUCC 21-0008) prepared from 40-days-old cultures onto the wounded sites via pin-prick inoculation. Similarly, five noninoculated plants sprayed with sterile water served as controls. Plants were placed in a growth chamber at 25℃ on a 12-h fluorescent light/dark regime and daily sprayed with sterile distilled water. After two weeks, observed symptoms were similar to those from natural infections. No disease symptoms were found on control plants. The fungus O. leptostyla was reisolated from the diseased leaves and characterized morphologically. O. leptostyla is a global pathogen and has been reported to cause the leaf spot in many walnut trees, viz. J. ailantifolia, J. californica, J. cinerea, and J. major, etc. To our knowledge, this is the first report of O. leptostyla causing brown leaf spot on Juglans hybrid (J. regia × J. sigillata) in China. The increasing risk of this pathogen in the walnut-growing areas of Sichuan Province of China needs a further exploration and outreach effort to develop effective control measures. Chunlin Yang, Feng Liu, and Qian Zeng contributed equally to this paper.

5.
Plant Dis ; 2021 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-34170759

RESUMEN

Juglans sigillata Dode (Iron walnut) is mostly distributed in southwestern China, and valued for wood and nuts (Feng et al. 2018). In April 2020, we surveyed a walnut garden located in Baisha Town, Wanyuan City, (Sichuan, China), where brown spot symptoms were observed on leaves of ten trees among of 100 plants, and this disease can result in a reduced growth potential when trees are severely infected. Necrotic and subcircular lesions with conidiamata were observed on diseased leaves. Symptomatic leaves were collected and taken back to the laboratory forfurther analysis. Using the single spore isolation technique developed by Chomnunti et al. (2014), five isolates were grown from the infected leaves on Potato Dextrose Agar medium (PDA). The five isolates had similar colony morphology, which was initially white, suborbicular, gradually turning yellowish with black spots, developing fluffy aerial mycelium. Morphological characteristics were examined using light microscopy on the PDA. Conidiogenous cells were subcylindrical to cylindrical, or ampulliform, hyaline, rarely branched. Macroconidia were lunate, reniform, hyaline, 1-3-septate, mostly 1-septate, distinctly constricted at the septum, the basal cell was bluntly rounded, the apical cell had an acute end, and the basal cell was equal to or larger than the apical cell, measuring 22 to 40.5 × 2.5 to 8.3 µm (mean = 32 × 6.2 µm, n = 50). Microconidia were botuliform, or subfusiform, hyaline, both ends were rounded, straight or curved, aseptate, and measured 10 to 28.5 × 1.9 to 3.7 µm (mean= 17.2 × 2.7 µm, n = 20). A multilocus approach was conducted for precise identification of a representative isolate SICAUCC 20-0012. The internal transcribed spacer regions (ITS), guanine nucleotide-binding protein subunit beta gene (MS204), and translation elongation factor 1-alpha (tef1-α) of isolate SICAUCC 20-0012 were amplified and sequenced as described by Sogonov et al. (2008) and Walker et al. (2012a). GenBank Accession Nos. for ITS, MS204, and tef1-α are MW250303, MW246773, and MW246775, respectively. Phylogenetic analyses showed 100% support with Ophiognomonia leptostyla (Fr.) Sogonov, and the morphology was consistent with the asexual stage of O. leptostyla documented by Walker et al. (2012b). To test Koch's postulates, five healthy plants of J. sigillata (2- to 3-year-old) with 5-8 leaves per plant were inoculated with conidial suspensions (104 conidia/mL) after wounded with a small pin as described by Desai et al. (2019), and the same number of healthy plants were wounded and sprayed with sterile distilled water as controls. Plants were sprayed regularly with distilled water every day and placed in a growth chamber at 25℃ with a 12-h fluorescent light/dark regimen. After 15 days, typical brown spot symptoms developed on inoculated leaves, but not on the controls. The fungus O. leptostyla was reisolated from the lesion as described above but not from non-inoculated leaves. O. leptostyla has been reported on some walnut trees; for example: J. ailantifolia, J. californica, J. cinerea, J. hindsii, J. major, J. mandshurica, J. nigra, and J. regia (Farr & Rossman 2020). However, to our knowledge, this is the first report of O. leptostyla causing brown leaf spot on J. sigillata. J. sigillata is an economically important tree in southwest China, and fungicide treatments should be considered to prevent the spread of this fungus before it becomes more widespread. Chunlin Yang, Yu Deng, and Feihu Wang contributed equally to this work. This research was supported by the Key Research and Development Project of Sichuan Province (2021YFYZ0032).

6.
Plant Dis ; 2020 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-32729801

RESUMEN

Livistona chinensis (Jacq.) R.Br. ex Mart. belonging to monocotyledonous Palmaceae, is widely distributed in Eastern Asia, and a common ornamental plant in Southern China (Li et al. 2019, Wu et al. 2019). In November 2019, epidemics of leaf blight were discovered on aged leaves of L. chinensis in the campus of Sichuan Agricultural University, where disease incidence was up to 90% among the cultivated plants, but without resulting in the death of the host. Initial symptoms appeared chlorotic spots on the upper part of leaves, then spots expanded and turned brown. Subsequently, the enlarged spots developed necrotic tissues in the center with brown to dark brown margin. At later stages, conidia and conidiophores were observed on the surface of lesions with the aid of a microscope. As the disease progressed, multiple lesions usually coalesced to cause extensive tissue necrosis at third or more parts of the leaf. Three isolates were obtained from diseased leaves with a single spore isolation referred to Chomnunti et al. (2014), and cultured on potato dextrose agar (PDA) under a 12-h photoperiod and 25±1℃. The colonies were gray to gray-olivaceous with an olivaceous-black reverse side, and measured approximately 7 cm in diameter after 6 days. The conidiophores were macronematous, semimacronematous or micronematous, erect, straight or slightly flexuous, filiform to narrowly cylindrical-oblong, occasionally branched, pale olivaceous-brown, wider at the base, 1 to 8 septate, 14-104 × 3-6.8 µm (x̅ =57.7 × 4.9 µm, n=30). Conidiogenous cells were integrated, terminal, intercalary or pleurogenous, cylindrical-oblong, 9-21 × 4-5.9 µm (x̅ =15 × 4.9 µm, n=20), thick walled, usually aseptate, occasionally 1-2-septate, with 1-5 apically crowed loci. Ramoconidia were almost oblong, aseptate, 4-8.4 × 3-5.7 µm (x̅ =6.9 × 4.6 µm, n=20). Conidia were numerous, catenate, in branched chains, small terminal conidia, subglobose or ovoid, and intercalary conidia were ovoid, limoniform, fusiform, aseptate, 2.9-5.5 × 2-5 µm (x̅ =4 × 3.5 µm, n=20). The representative isolate SICAUCC 20-0007 was used for Genomic DNA extraction, and the internal transcribed spacer (ITS), translation elongation factor 1 alpha (TEF 1-α) and partial actin (ACT) regions were amplified using the primer pairs ITS5/ITS4 (White et al. 1990), EF1-728F/EF-2 (O'Donnell et al. 1998, Carbone et al. 1999) and ACT-512F/ACT-783R (Carbone et al. 1999), respectively. Nucleotide BLAST in GenBank revealed identity with those of C. perangustum, the ITS (MT427730) had 100% identity with MF473185 and MF473177, TEF 1-α (MT441922) had 100% identity with HM148379 and MF473595, ACT (MT441917) had 100% identity with HK521577 and MH047335. The phylogenetic tree combined with ACT, ITS, and TEF 1-α genes (Fig. 1) and morphological characteristics confirmed the identification as C. perangustum defined by Bensch et al. (2010). To determine pathogenicity, five potted plants were inoculated with conidial suspensions (105 conidia/ml) prepared from 1-week-old cultures of the isolate SICAUCC 20-0007 onto the wounded sites via pin-prick inoculation (five to eight leaves per plant with roughly 1 to 2-year-old), and the same amount of healthy plant was sprayed with distilled water as controls. Plants were sprayed regularly with distilled water every day and placed under a 12-h photoperiod and 25±1℃. About fifteen days later, faint yellow to yellowish-brown spots were found on inoculated leaves and were similar to those previously observed and no symptoms developed on the control plants. After a month, leaf blight was observed and the pathogenic fungus was re-isolated from the inoculated tissues. Previous reports have shown that C. perangustum causes leaf spot on Myrica rubra (Lour.) Siebold & Zucc. in China (Lu et al. 2015). To our knowledge, this is the first report of C. perangustum causing leaf blight of L. chinensis in the world. This disease potentially reduces the ornamental value under favorable conditions, and proper control strategies should be implemented.

7.
Plant Dis ; 2020 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-32720887

RESUMEN

Phoenix canariensis Chabaud is a vital ornamental and widely planted in the urban landscape of China (Lan et al. 2019). In December 2019, six of seven P. canariensis plants exhibited typical symptoms of leaf spot in Chengdu campus of Sichuan Agricultural University in Sichuan, China, with roughly 80% leaves per plant affected. Symptomatic leaves initially showed dark brown spots with a yellow halo at the periphery. As the disease progressed, spots gradually expanded and eventually formed necrotic spots, with the whole leaf dying when severely infected. 10 diseased leaves from different plants were collected in December 2019 and deposited in Sichuan Agricultural University Herbarium. A single spore isolation was performed following Chomnunti et al. (2014) and transferred to potato dextrose agar (PDA). Five fungal isolates were obtained from five different infected leaves respectively and deposited in Sichuan Agricultural University Culture Collection. The fungal colonies were incipiently greyish-white becoming pale brown at the margins and dark brown in the center. The reverse was the same as the obverse with radial cracking at the center. Morphological characteristics on the host were examined by light microscopy. Ascomata were semi-immersed to immersed, black, pyriform to subglobose, and measured 180-310 × 140-260 µm. The peridium comprised several layers of hyaline cells of textura angularis and measured 9-27 µm wide. Pseudoparaphyses were numerous, septate, hyaline, usually longer than asci. Asci were 8-spored, bitunicate, cylindric-clavate, and measured 50-95 × 8-11.5 µm (n=35). Ascospores were 1-septate, straight or slightly curved, hyaline, usually with globose appendages at both ends, and measured 14-18.5 × 4-6.5 µm (n=50). Conidiogenesis was not observed on PDA incubated four months at 25℃ and 95 % relative humidity on a 12-h fluorescent light/dark incubation. Morphology was consistent with the sexual stage of Neovaginatispora fuckelii (Sacc.) A. Hashim. et al. described by Hashimoto et al. 2018, Tennakoon et al. 2018, and Hyde et al. 2020. The rDNA internal transcribed spacer region (ITS), 28S large subunit (LSU), 18S small subunit (SSU), translation elongation factor 1-alpha (TEF 1-α), and RNA polymerase II subunit 2 (RPB2) gene regions were amplified by using the primers ITS5/ITS4, LR0R/LR5, NS1/NS4, EF1-983F/EF1-2218R, and fRPB2-5F/fRPB2-7cR, respectively. The DNA amplification products of the representative isolate SICAUCC 20-0008 isolated from SICAU 20-0008 were sequenced and accessioned in GenBank, viz MT427731, MT427734, MT427738, MT441923, and MT441920, respectively. The sequences were compared with the GenBank database using nucleotide BLAST, and these five sequences were great identical with the sequences of the fungus N. fuckelii (GenBank accession no. ITS, LC001732, 522/524, 99.62%; LSU, AB619009, 839/840, 99.88%; SSU, AB618690, 976/976, 100%; TEF 1-α, LC001750, 895/912, 98.14%; RPB2, MN482130, 935/935, 100%). Using phylogenetic analysis in which reference sequences collected from GenBank were included, the isolate SICAUCC 20-0008 clustered within N. fuckelii with high bootstrap support (Fig. 1). To conduct Koch's postulates, fifteen healthy P. canariensis 2 to 3-year-old plants were inoculated by placing a mycelium plug from the growing margin of 15-day-old colonies upside down directly onto fresh wounds punctured with a fine needle. Five healthy plants were inoculated with a sterile agar plug as the control. Plants were incubated in a growth chamber at 25 ± 1℃ and 95% relative humidity on a 12-h fluorescent light/dark regimen. After ten days, the leaves of inoculated plants turned brown and gradually expanded and became necrotic spots, similar to symptoms observed in the field. The control plants were symptomless. The pathogen was re-isolated from leaf lesions and identified by morphological characteristics, whereas no fungus was recovered from control treatments. N. fuckelii has been often reported as a saprobe on numerous hosts including species of Acer, Carpinus, Carya, Epilobium, Prunus, Quercus, Rhus, Salix, and Vitis, as well as other genera (Thambugala et al. 2015, Hashimoto et al. 2018, Hyde et al. 2020). To our knowledge, this is the first report of N. fuckelii causing leaf spot on P. canariensis. Some proteaceous plants and other palms are known to be infected by this fungus (Hyde et al. 2000, Taylor et al. 2000), which may result in a great threat to ornamental horticulture. Fungicides treatments should be considered to prevent the damage to plants and spread of this fungus.

8.
J Fungi (Basel) ; 8(7)2022 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-35887458

RESUMEN

In the present study, we surveyed the ascomycetes from bamboo of Phyllostachys across Sichuan Province, China. A biphasic approach based on morphological characteristics and multigene phylogeny confirmed seven species, including one new genus, two new species, and five new host record species. A novel genus Paralloneottiosporina is introduced to accommodate Pa. sichuanensis that was collected from leaves of Phyllostachys violascens. Moreover, the newly introduced species Bifusisporella sichuanensis was isolated from leaves of P. edulis, and five species were newly recorded on bamboos, four species belonging to Apiospora, viz. Ap. yunnana, Ap. neosubglobosa, Ap. jiangxiensis, and Ap. hydei, and the last species, Seriascoma yunnanense, isolated from dead culms of P. heterocycla. Morphologically similar and phylogenetically related taxa were compared. Comprehensive descriptions, color photo plates of micromorphology are provided.

9.
J Fungi (Basel) ; 7(8)2021 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-34436167

RESUMEN

This study led to the discovery of three entomopathogenic fungi associated with Kuwanaspis howardi, a scale insect on Phyllostachys heteroclada (fishscale bamboo) and Pleioblastus amarus (bitter bamboo) in China. Two of these species belong to Podonectria: P. kuwanaspidis X.L. Xu & C.L. Yang sp. nov. and P. novae-zelandiae Dingley. The new species P. kuwanaspidis has wider and thicker setae, longer and wider asci, longer ascospores, and more septa as compared with similar Podonectria species. The morphs of extant species P. novae-zelandiae is confirmed based on sexual and asexual morphologies. Maximum likelihood and Bayesian inference analyses of ITS, LSU, SSU, tef1-α, and rpb2 sequence data provide further evidence for the validity of the two species and their placement in Podonectriaceae (Pleosporales). The second new species, Microcera kuwanaspidis X.L. Xu & C.L. Yang sp. nov., is established based on DNA sequence data from ITS, LSU, SSU, tef1-α, rpb1, rpb2, acl1, act, cmdA, and his3 gene regions, and it is characterized by morphological differences in septum numbers and single conidial mass.

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