scholarly journals Etiology of Cyclocarya paliurus Anthracnose in Jiangsu Province, China

2021 ◽  
Vol 11 ◽  
Author(s):  
Xiang-rong Zheng ◽  
Mao-jiao Zhang ◽  
Xu-lan Shang ◽  
Sheng-zuo Fang ◽  
Feng-mao Chen
Keyword(s):  
Sensu Stricto ◽  
Jiangsu Province ◽  
Single Spore ◽  
Fungicide Sensitivity ◽  
Cyclocarya Paliurus ◽  
Yield And Quality ◽  
Great Yield ◽  
Young Leaves ◽  
Phylogenetic Grouping ◽  
Potential Alternative

Cyclocarya paliurus is an extremely valuable and multifunctional tree species whose leaves have traditionally been used in used in medicine or as a medicinal tea in China. In recent years, anthracnose has been frequently observed on young leaves of C. paliurus in several nurseries located in Jiangsu Province, resulting in great yield and quality losses. To date, no information is available about the prevalence of C. paliurus anthracnose in China. The main purpose of the present study was to characterize the etiology of C. paliurus anthracnose. Phylogenetic analysis of the eight-loci concatenated dataset revealed that all 44 single-spore Colletotrichum isolates belonged to three species in the Colletotrichum gloeosporioides species complex, namely, Colletotrichum aenigma, Colletotrichum fructicola, and C. gloeosporioides sensu stricto. Phenotypic features, including the colony appearance and the morphology of conidia, appressoria, and ascospores, were consistent with the phylogenetic grouping. Virulence tests validated that the three Colletotrichum species could cause typical symptoms of anthracnose on C. paliurus leaves, similar to those observed in the field. The optimum mycelial growth temperature ranged from 25 to 30°C for all representative isolates, while C. gloeosporioides s. s. isolates exhibited greater tolerance to high temperature (40°C). Fungicide sensitivity assays indicated that all three Colletotrichum species were sensitive to tetramycin, which may be a potential alternative for the management of C. paliurus anthracnose. To our knowledge, this study provides the first report of C. aenigma, C. fructicola, and C. gloeosporioides s. s. causing C. paliurus anthracnose in China as well as in the world.

Biological species of Armillaria in the mixedwood forest of northern Ontario

1988 ◽  
Vol 18 (7) ◽  
pp. 872-874 ◽  
Author(s):  
M. T. Dumas
Keyword(s):  
Sensu Stricto ◽  
Biological Species ◽  
Single Spore ◽  
Northern Ontario

The Armillaria complex of the mixedwood forest of northern Ontario is composed of four intersterile species. Single-spore isolates of these biological species were compatible with Anderson and Ullrich's biological species I (Armillariaobscura), III, V, and VII (Armillariabulbosa). Armillariaobscura and biological species V were the most common. Armillariamellea sensu stricto was not collected.

scholarly journals First Report of Colletotrichum acutatum Causing a Leaf Spot on Myrica cerifera in Florida

Plant Disease ◽  
2006 ◽  
Vol 90 (9) ◽  
pp. 1263-1263 ◽  
Author(s):  
S. J. Mackenzie ◽  
L. M. Takahashi ◽  
J. C. Mertely ◽  
T. E. Seijo ◽  
N. A. Peres
Keyword(s):  
Colletotrichum Acutatum ◽  
Rrna Gene ◽  
Single Spore ◽  
Myrica Cerifera ◽  
First Report ◽  
Central Florida ◽  
Potted Plants ◽  
5.8S Rrna Gene ◽  
Young Leaves ◽  
Plastic Bag

Wax myrtle (Morella cerifera (synonym Myrica cerifera) (L.) Small) is a native tree used in Florida landscapes. In the summer of 2005 and spring of 2006, small necrotic spots were observed on young leaves in two commercial nurseries in central Florida. Lesions were dark brown-to-black and eventually coalesced to form large, irregular necrotic areas. Leaves with large lesions abscised prematurely, defoliating the entire plant. Conidia formed on acervuli were observed on the surface of the largest lesions and were tentatively identified as a Colletotrichum sp. Isolations from the edges of lesions were made on potato dextrose agar (PDA) after surface disinfestation of leaf pieces in 0.6% NaOCl for 30 sec. Red chromogenic colonies developed after 5 days of incubation at 24°C. Colonies produced hyaline, oblong conidia with pointed ends averaging 14 × 4 μm and were identified as Colletotrichum acutatum J.H. Simmonds (1). The sequence from internal transcribed spacer regions 1 and 2 and the 5.8s rRNA gene of the rDNA repeat for an isolate (GenBank Accession No. DQ839609) was 100% identical to sequence from the same region of 36 C. acutatum isolates in the NCBI database. These isolates came from at least 16 different hosts, including seven ornamental hosts. There were three isolates from blueberry among the matches (Accession Nos. AB219029, AJ301911, and AJ301905), and the rDNA sequence was also identical to the sequence obtained in our laboratory for a chromogenic C. acutatum isolate from blueberry. Three single-spore isolates were tested for pathogenicity on potted plants in the greenhouse. Two young shoots were spray inoculated with a suspension (1 × 106 conidia/ml) of each isolate. Shoots were covered with a plastic bag for 24 h and maintained at 26.5°C. Two shoots were sprayed with sterile water as a control and similarly covered. All isolates produced brown spots on the youngest leaves 3 to 5 days after inoculation; no symptoms developed on control shoots. The fungus was reisolated from all inoculated shoots. To our knowledge, this is the first report of C. acutatum on wax myrtle in Florida. The disease has a potential to spread and become a significant problem for the cultivation of this species in ornamental nurseries in Florida. Reference: (1) J. H. Simmonds. Qld. J. Agric. Anim. Sci. 22:437, 1965.

scholarly journals Diversity, Pathogenicity, and Fungicide Sensitivity of Colletotrichum Species Associated with Apple Anthracnose in South Korea

Plant Disease ◽  
2020 ◽  
Vol 104 (11) ◽  
pp. 2866-2874
Author(s):  
Chi Hyun Kim ◽  
Oliul Hassan ◽  
Taehyun Chang
Keyword(s):  
Mycelial Growth ◽  
Morphological Characteristics ◽  
Sensu Stricto ◽  
Culture Collection ◽  
Potato Dextrose Agar ◽  
Fungicide Sensitivity ◽  
Colletotrichum Species ◽  
Highly Sensitive ◽  
The Republic ◽  
Apple Fruits

Apple fruits with anthracnose symptoms were collected from commercial apple orchards in different regions of the Republic of Korea, and isolations were made on potato dextrose agar to isolate the causal agents. The fungal isolates were identified based on their morphological characteristics, growth rates, and multigene sequences. Nine isolates were identified via phylogenetic analysis: three Colletotrichum fructicola, two C. fioriniae, one C. gloeosporioides sensu stricto (s.s.), two C. nymphaeae, and one C. siamense isolates. The pathogenicity of the Colletotrichum isolates was tested using detached apple fruits under laboratory conditions. This study also reidentified six Colletotrichum isolates responsible for apple anthracnose, which were deposited in the Korean Agricultural Culture Collection. Among the six isolates, three were identified as C. siamense (deposited as C. gloeosporioides s.s.), and three were C. nymphaeae (deposited as C. acutatum s.s.). All the Colletotrichum species identified in this study were highly sensitive to tebuconazole in terms of inhibition of mycelial growth (EC50 value of 0.12 to 2.1 μg/ml).

scholarly journals Valdensinia heterodoxa Peyronel as a New Pathogen of Blueberry in Poland

Plant Disease ◽  
2014 ◽  
Vol 98 (5) ◽  
pp. 688-688
Author(s):  
R. Dzięcioł ◽  
E. Mirzwa-Mróz ◽  
E. Zielińska ◽  
M. Wińska-Krysiak ◽  
W. Wakuliński
Keyword(s):  
Soil Surface ◽  
Its Region ◽  
Vaccinium Corymbosum ◽  
Leaf Blight ◽  
Single Spore ◽  
Initial Symptoms ◽  
Sterile Needle ◽  
Young Leaves ◽  
Necrotic Spots ◽  
Thermal Cycler

Valdensia leaf blight on blueberry in Poland was reported in one commercial nursery plantation near Prażmów, Mazovia voivodship, where heavy defoliation was observed on cv. Bluecrop, grown in nursery pots, in August 2011. Older fruiting bushes were only slightly affected by the disease. Initial symptoms of the disease were small, oval to circular zonated necrosis surrounded with dark brown borders that enlarged on the leaves throughout the canopy. Multicellular, hyaline or light brown, star-shaped conidiospores were observed on the necrotic areas. The mean length of 50 conidiospores from the end of head to the end of arm apex was 307 to 348 μm (4). Eight single-spore isolates of the fungus were obtained. Single conidiospores were picked up from necrotic spots on leaves and transferred with sterile needle on potato dextrose agar (PDA) and incubated at 20°C under ambient light. After 10 days of incubation, total DNA was extracted. Amplification of the internal transcribed spacer (ITS) region of rDNA was done using primers ITS1F and ITS4A (1). PCRs were carried out as follows: initial denaturation at 94°C for 2 min, denaturation at 94°C for 1 min, annealing at 57°C for 1 min, extension at 72°C for 1 min, and final extension at 72°C for 5 min for 28 cycles (Applied Biosystems Veriti 96 Wel Thermal Cycler). Amplicons, which were approximately 520 bp, were sequenced and nucleotide sequences were analyzed by Clustal W2EBI. The sequences of all eight isolates showed 100% similarity to each other and were compared with sequences stored in GenBank using BLAST. Sequences were 525 bp long and showed 100% homology to Valdensinia heterodoxa Peyronel, Sclerotiniaceae (anamorph: Valdensia heterodoxa Peyronel) from Japan and Norway (Accession Nos. AB663682 and Z81447, respectively) (3). The sequence from one isolate was submitted to GenBank (Accession No. KF212190). To fulfill Koch's postulates, each of the eight isolates was used to inoculate 20 healthy young leaves of Vaccinium corymbosum L. cv. Bluecrop and bilberry (V. myrtillus L.) (10 leaves per plant). Mycelial plugs 5 mm in diameter were taken from PDA cultures, approximately 20 days old, and used as inoculum and placed in the center of each leaf and moistened with sterile distilled water. Mycelium-free plugs were used as control. Inoculated leaves were placed in plastic box and incubated at 20°C in laboratory for 5 days, at which time small necrotic lesions consistent with initial symptoms of the disease were observed. Isolates obtained from these symptoms were morphologically identical to those used for inoculation. Control leaves did not show any disease symptoms. Valdensia leaf blight occurrence may be attributed to rainy July and August 2011 and long presence of water on soil surface. In Poland, Valdensinia heterodoxa causes heavy defoliation of Vaccinium myrtillus in pine stands and is a common pathogen of some herbaceous plants (2). To our knowledge, this is the first report of Valdensia leaf blight on highbush blueberry in Poland. References: (1) I. Larena et al. 75:187, 1999. (2) W. Mułenko and S. Woodward. Mycologist 10:69, 1996. (3) S. Nekoduka et al. J. Gen. Plant Pathol. 78:151, 2012. (4) S. Zhao and S. F. Shamoun. Mycology 1:113, 2010.

scholarly journals Within-Field Variation of Fusarium graminearum Isolates for Aggressiveness and Deoxynivalenol Production in Wheat Head Blight

2012 ◽  
Vol 102 (1) ◽  
pp. 128-134 ◽  
Author(s):  
Firas Talas ◽  
Rasha Kalih ◽  
Thomas Miedaner
Keyword(s):  
Fusarium Graminearum ◽  
Sensu Stricto ◽  
Wheat Breeding ◽  
Phenotypic Variance ◽  
Environment Interaction ◽  
Field Variation ◽  
Head Blight ◽  
Single Spore ◽  
Spring Wheat Cultivar ◽  
Multiple Resistance Genes

Fusarium head blight (FHB), caused by Fusarium graminearum sensu stricto (s.s.), causes tremendous annual yield losses in wheat worldwide. Variation of aggressiveness of isolates from individual field populations in terms of FHB infection and deoxynivalenol (DON) concentration in the host are important population parameters reflecting parasitic ability. Our main objective was to estimate the variation of both traits within three populations of F. graminearum s.s., each consisting of 30 single-spore isolates collected from small wheat fields in Germany, and to compare it with 11 isolates of a collection (F. graminearum collection) from four countries. The same isolates were characterized using 19 single-sequence repeat markers. All isolates were spray inoculated on a moderately resistant spring wheat cultivar at two field locations over 2 years (i.e., in four environments). The genotypic proportion of phenotypic variance (σ2G) within populations was significant (P < 0.01) for both traits, and the σ2G × environment interaction was even more important for mean FHB severity. Ranges in mean FHB severity and DON concentration in the host were only slightly smaller for the field populations than for the F. graminearum collection. Both traits were significantly (P < 0.05) correlated within and across populations. A further partitioning of σ2G revealed 72% of σ2G within and 28% of σ2G across populations for both traits. Molecular variance of the three populations was similarly distributed (73.6% within versus 26.4% between populations). In view of this high within-field variation for traits of parasitic ability and selection, neutral molecular markers, multiple resistance genes of different origin should be employed in wheat breeding programs to obtain a long-term stable FHB resistance.

scholarly journals Characterization and Fungicide Sensitivity of Colletotrichum spp. from Different Hosts in Shandong, China

Plant Disease ◽  
2019 ◽  
Vol 103 (1) ◽  
pp. 34-43 ◽  
Author(s):  
Lifei He ◽  
Xiaoxu Li ◽  
Yangyang Gao ◽  
Beixing Li ◽  
Wei Mu ◽  
...  
Keyword(s):  
Mycelial Growth ◽  
Phylogenetic Analyses ◽  
Morphological Characteristics ◽  
Sensu Stricto ◽  
Shandong Province ◽  
Effective Control ◽  
Tea Leaves ◽  
Colletotrichum Species ◽  
Great Yield ◽  
Solid Foundation

Anthracnose, caused by Colletotrichum species, can severely infect the fruits and leaves of more than 30 plants and thus results in great yield and quality losses. To identify the major Colletotrichum species infecting walnut fruits, strawberry leaves, grape fruits, and tea leaves in Shandong Province, China, 101 strains were collected and isolated. The morphological characteristics of all isolates were observed, and multilocus phylogenetic analyses (ITS, GAPDH, ACT, TUB2, CAL, CHS-1, and HIS3) were conducted on the representative isolates. The strains were identified as five Colletotrichum species, namely, C. gloeosporioides sensu stricto, C. fructicola, C. camelliae, C. acutatum sensu stricto, and C. viniferum. Among them, C. viniferum was reported for the first time from walnut fruits and strawberry leaves in Shandong Province, China. Corresponding leaves or fruits were used as a model to clarify the pathogenicity of these isolates. The results showed that C. fructicola obtained from strawberry leaves was more aggressive than C. viniferum. All of the isolates obtained from various hosts were highly sensitive to pyraclostrobin, difenoconazole, fludioxonil, tebuconazole, pyrisoxazole, and tetramycin in terms of mycelial growth inhibition (EC50 values of 0.07 to 1.63 mg/liter). The fastest mycelial growth was observed in the temperature range of 25–28°C for all isolates. In addition, anthracnose symptoms occur frequently under these conditions. Overall, this study can improve the understanding of Colletotrichum species causing anthracnose in walnut fruits, strawberry leaves, grape fruits, and tea leaves and can provide a solid foundation for the effective control of this disease in different hosts.

scholarly journals Fusarium Populations on Chinese Barley Show a Dramatic Gradient in Mycotoxin Profiles

2008 ◽  
Vol 98 (6) ◽  
pp. 719-727 ◽  
Author(s):  
L. Yang ◽  
T. van der Lee ◽  
X. Yang ◽  
D. Yu ◽  
C. Waalwijk
Keyword(s):  
Yangtze River ◽  
Pcr Primers ◽  
Sympatric Species ◽  
Sensu Stricto ◽  
Nucleotide Polymorphisms ◽  
The Yangtze River ◽  
Head Blight ◽  
Single Spore ◽  
Single Nucleotide ◽  
Large Gene

We report on a large gene bank of Fusarium isolates established by a broad survey conducted in 2005 in which infected barley ears were collected in 23 counties of seven provinces and two municipalities along the Yangtze River in China. In total, 1,894 single spore isolates were obtained. The isolates were characterized at the species level by a newly developed and robust set of diagnostic primers based on single nucleotide polymorphisms (SNPs) among members of the F. graminearum clade. In addition, we determined their chemotype using previously described polymerase chain reaction (PCR) primers. The results showed that in all regions F. asiaticum was the predominant species causing Fusarium head blight (FHB) on barley in China (N = 1,706), while in the upper valleys of the Yangtze River also F. graminearum sensu stricto, F. meridionale, and F. proliferatum were found. Major differences in the chemotypes were found in the F. asiaticum populations, from very high to exclusive nivalenol (NIV) chemotypes in the mountainous upper valleys of the Yangtze River to predominantly deoxynivalenol (DON) chemotypes in the middle and lower valleys. In contrast to the F. asiaticum isolates from three counties in Sichuan province, which were largely NIV producers (278 of 291), F. graminearum isolates from these sampling sites were for the vast majority (27 of 28) DON producers, indicating that despite sharing the same habitat, these sympatric species apparently have unique mycotoxin chemotypes.

Two new species of Pisolithus (Sclerodermataceae) from Australasia, and an assessment of the confused nomenclature of P. tinctorius

Phytotaxa ◽  
2018 ◽  
Vol 348 (3) ◽  
pp. 163 ◽  
Author(s):  
TERESA LEBEL ◽  
SHAUN PENNYCOOK ◽  
MATTHEW BARRETT
Keyword(s):  
New Zealand ◽  
New Caledonia ◽  
Sensu Stricto ◽  
Morphological Data ◽  
Northern Australia ◽  
Sequence Analyses ◽  
Acacia Species ◽  
Distribution Ranges ◽  
Its Nrdna ◽  
Phylogenetic Grouping

Based on morphological data and ITS nrDNA sequence analyses, we formally describe two species from the phylogenetic grouping ‘Martin sp. 10’ as Pisolithus thermaeus sp. nov., endemic to New Zealand, and P. tympanobaculus sp. nov. from Australia. All Pisolithus species in New Zealand are restricted in distribution to geothermally active areas, in ectomycorrhizal association with Kunzea tenuicaulis. In Australia species occur in a broad range of habitats in association with Eucalyptus or Acacia species; and in New Caledonia species form associations with various Myrtaceae or an Acacia species. The distribution ranges of Pisolithus albus, P. marmoratus and P. croceorrhizus are extended to include the Kimberley and Top End regions of northern Australia. We also confirm that neither P. arenarius, nor P. tinctorius sensu stricto, nor P. arhizus are currently known to occur in Australia or New Zealand. The long-used but never formalized combination Pisolithus albus (Cooke & Massee) Priest is validated here and nomenclatural knots relating to three different usages of the name Pisolithus tinctorius are unraveled and suggestions made for their resolution.

scholarly journals Phenotypic and Genetic Characterization of Botrytis cinerea Population from Kiwifruit in Sichuan Province, China

Plant Disease ◽  
2019 ◽  
Vol 103 (4) ◽  
pp. 748-758 ◽  
Author(s):  
Yan-gang Pei ◽  
Qin-jun Tao ◽  
Xiao-juan Zheng ◽  
Ying Li ◽  
Xiao-fang Sun ◽  
...  
Keyword(s):  
Botrytis Cinerea ◽  
Gray Mold ◽  
Sensu Stricto ◽  
Sichuan Province ◽  
Genetic Characteristics ◽  
Morphological Criteria ◽  
Young Leaves ◽  
Pathogen Variability ◽  
Botryotinia Fuckeliana ◽  
Phenotypic And Genetic Characterization

Botrytis cinerea (anamorph of Botryotinia fuckeliana) causes gray mold on numerous plants, including kiwifruit. The primary aim of this study was to investigate the phenotypic and genetic characteristics of the Botrytis cinerea population from kiwifruit in Sichuan Province, China. In all, 176 isolates were collected from kiwifruit orchards from eight geographic regions in Sichuan. All isolates were identified as B. cinerea sensu stricto based on the combined datasets, including morphological criteria, determination of the Bc-hch allele, and phylogenetic analysis of the genes RPB2, G3PDH, and HSP60. Three colony types (i.e., sclerotial, mycelial, and conidial) were observed on potato dextrose agar after 2 weeks, with sclerotial isolates, the predominant category, accounting for 40.91%. No obvious differences in microscopic characteristics were observed among the three types. Three genotypes of transposable elements were identified in the B. cinerea population: boty, flipper, and transposa types. The most prevalent genotype from different geographic populations of B. cinerea was transposa; in contrast, the flipper genotype accounted for only 3.98% of the total population, whereas the vacuma genotype was absent. According to MAT locus amplification, 87 and 89 isolates are MAT1-1 and MAT1-2 type, respectively, and the two mating types were found to be balanced overall in the population. Forty-eight representative isolates were all able to cause gray mold to some extent, and disease severities were significantly different between the cultivars Hongyang and Hort16A (P < 0.01). Disease severity was significantly greater on young leaves than on mature leaves (P < 0.01). No significant relationship was found between pathogenicity and geographical region, colony type, or transposon distribution. The results obtained in the present study suggest a relatively uniform species diversity of Botrytis but rich phenotypic and genetic differentiation within the B. cinerea population on kiwifruit in China. Utilizing resistant cultivars and rain-shelter cultivation instead of fungicides may be an effective approach to delaying pathogen variability.

Aggressiveness of Small-Spored Alternaria spp. and Their Sensitivity to Succinate Dehydrogenase Inhibitor Fungicides

Plant Disease ◽  
2022 ◽  
Author(s):  
Sarah Budde-Rodriguez ◽  
Julie Sherman Pasche ◽  
Fereshteh Shahoveisi ◽  
Ipsita Mallik ◽  
Neil C Gudmestad
Keyword(s):  
Leaf Spot ◽  
Sensu Stricto ◽  
Baseline Sensitivity ◽  
Fungicide Sensitivity ◽  
Commercial Potato ◽  
Brown Leaf Spot ◽  
Brown Leaf ◽  
Succinate Dehydrogenase Inhibitor

Brown leaf spot of potato is caused by a number of small-spored Alternaria spp. Alternaria alternata sensu stricto, Alternaria arborescens, and Alternaria tenuissima have been reported with increasing frequency in commercial potato fields. Potato cultivars with resistance to small-spored Alternaria spp. have yet to be developed; therefore, the application of foliar fungicides is a primary management strategy. Greenhouse inoculation assays demonstrated that isolates of these three small-spored Alternaria spp. were pathogenic to potato. Significant differences in aggressiveness were observed across isolates; however, there was no trend in aggressiveness based on species. Significant fungicide by isolate interactions in in vitro fungicide sensitivity and significant differences between baseline and non-baseline isolates were observed in all three small-spored Alternaria spp. The ranges of in vitro sensitivity of A. alternata baseline isolates to boscalid (EC50 <0.010 to 0.89 µg/ml), fluopyram (<0.010 to 1.14 µg/ml) and solatenol (<0.010 to 1.14 µg/ml) were relatively wide when compared to adepidyn (<0.010 to 0.023 µg/ml). The baseline sensitivity of A. arborescens and A. tenuissima isolates to all four fungicides were less than 0.065 µg/ml. Between 10 and 21% of non-baseline A. alternata isolates fell outside the baseline range established for the four SDHI fungicides evaluated. In A. arborescens, 10 to 80% of non-baseline isolates had higher sensitivities than the baseline. A. tenuissima isolates fell outside the baseline for boscalid (55%), fluopyram (14%), and solatenol (14%) but none fell outside the baseline range for adepidyn. Evaluations of in vivo fungicide efficacy demonstrated that most isolates were equally controlled by the four SDHI fungicides. However, reduced boscalid efficacy was observed for four isolates (two each of A. arborescens and A. tenuissima) and reduced fluopyram control was observed in one A. alternata isolate. Results of these studies demonstrate that isolates of all three species could be contributing to the brown leaf spot pathogen complex and that monitoring both species diversity and fungicide sensitivity could be advantageous for the management of brown leaf spot in potatoes with SDHI fungicides.

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