scholarly journals Trichothecium roseum Causes Fruit Rot of Tomato, Orange, and Apple in Pakistan

Plant Disease ◽  
2014 ◽  
Vol 98 (9) ◽  
pp. 1271-1271 ◽  
Author(s):  
M. I. Hamid ◽  
M. Hussain ◽  
M. U. Ghazanfar ◽  
M. Raza ◽  
X. Z. Liu
Keyword(s):  
Sequence Analysis ◽  
Its Region ◽  
Molecular Techniques ◽  
Fruit Rot ◽  
Control Treatment ◽  
Distilled Water ◽  
Trichothecium Roseum ◽  
Fruit Samples ◽  
The World ◽  
Stereo Microscope

During a field survey of greenhouses and fresh markets in 2013, fruits of tomato, oranges, and apples exhibited rot symptoms with white mycelial growth and salmon-color sporulation in the vicinity of Sargodha city (32°5′1″ N, 72°40′16″ E), Pakistan. Diseased fruit samples were collected in plastic bags and taken to laboratory on ice for further diagnosis. Diseased fruits were observed under a stereo microscope and single spores were removed using an inoculating needle. Isolation from single spores showed pink to white colonies on potato dextrose agar (PDA) containing hyaline, 2-celled, ellipsoid to pyriform conidia (17 to 24 × 7 to 11 μm) with slanting and truncate basal mark and produced in clusters. Conidiophores were branched (105 to 254 × 2 to 4 μm) and hyphae were hyaline (3 to 5 μm in diameter). These characteristics of the fungus were similar to Trichothecium roseum (Pers.) as reported by Inácio et al. (1). Genomic DNA was extracted by using CTAB buffer from a single pure colony of one isolate of the fungus and PCR analysis was performed for ITS region and part of the 5′ end of the beta tubulin (TUB) gene (2,3). Single fragments of 550 bp and 1.5 kb length from ITS and TUB gene were amplified and sequenced (GenBank Accession Nos. KF975702 and KJ607590, respectively). Sequence analysis showed 99% similarity with T. roseum isolates from different regions of the world. Phylogenetic analysis (MEGA version 5.2 with WAG model) showed the close relatedness to the isolates of T. roseum from Pakistan and isolates from other parts of the world that revealed the low genetic variability of ITS region. TUB gene sequence analysis indicated 100% homology with isolates of T. roseum and to the other species in Hypocreales. Pathogenicity tests were performed on tomato cvs. Nova Mech and Rio Grande, orange cv. Kinnow, and on apple cv. Golden Delicious by inoculating five fruits from each cultivar. Spore suspensions (105 conidia/ml of sterilized distilled water) were inoculated into all wounded fruits (9 wounds/fruit) of each cultivar and incubated at 25°C for the development of symptoms. Five wounded fruits of each cultivar were inoculated with sterilized distilled water as a control treatment. The fruits were kept in plastic boxes and incubated in humid chambers for 5 days. The symptoms on apples were observed as brown rot with pinkish spores on rotted tissue. The cross section of apple fruits also showed the brown rotted tissues internally. The fungus developed mycelium and spores on the surface and caused severe rotting inside the tomato and citrus fruits. T. roseum was re-isolated by picking a single spore from rotted tissues of fruits under a stereo microscope, and culturing on PDA. The re-isolated fungus was confirmed morphologically and by molecular techniques. Tomato and apple has been reported as a host for T. roseum (1,4,5) but oranges have not. To our knowledge, this is the first record of T. roseum infecting tomato, oranges, and apples in Pakistan. References: (1) C. A. Inácio et al. Plant Dis. 95:1318. 2011. (2) K. O'Donnell, and E. Cigelnik. Mol. Phylogenet. Evol. 7:103, 1997. (3) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990. (4) Y. H. Yun et al. Afr. J. Microbiol. Res. 7:1128, 2013. (5) M. Žabka et al. Mycopathologia. 162:65, 2006.

scholarly journals A Tomato Fruit Rot Caused by Trichothecium roseum in Brazil

Plant Disease ◽  
2011 ◽  
Vol 95 (10) ◽  
pp. 1318-1318 ◽  
Author(s):  
C. A. Inácio ◽  
R. C. Pereira-Carvalho ◽  
F. G. A. Morgado ◽  
M. E. N. Fonseca ◽  
L. S. Boiteux
Keyword(s):  
Fungal Pathogens ◽  
Tomato Fruit ◽  
Its Region ◽  
The United States ◽  
Fruit Rot ◽  
Control Treatment ◽  
Postharvest Disease ◽  
Potato Dextrose Agar Medium ◽  
Trichothecium Roseum ◽  
Greenhouse Tomatoes

Fruit rots caused by distinct fungal pathogens are commonly observed on tomatoes (Solanum lycopersicum L.) throughout all major production areas in Brazil. Samples of fruits displaying white mycelial growth associated with a profuse salmon-color sporulation were collected in greenhouse-grown tomatoes in Brasília-DF in February 2011. The isolated fungus displayed pink-to-white colonies containing several conidiophores with conidia. Mycelia displayed hyaline hyphae as much as 4 μm in diameter; conidiophores were simple or branched, 112 to 300 (360) μm long, and 2 to 4 μm wide. Conidia were produced in basipetal chains (frequently clustered), were ellipsoidal to pyriform with oblique and prominent truncate basal scars, two-celled, hyaline, and (14-) 16 to 26 (-28) × (6-) 7 to 10 (-12) μm. These characteristics allocated the specimen to Trichothecium roseum (Pers.). Koch's postulates were fulfilled for one fungal isolate by either spraying 10 intact fruits or by placing a drop of a spore suspension (adjusted to 105 conidia/ml) into three to five wounds created on 10 mature fruits of each of two tomato cultivars (Santa Clara and Dominador) by puncturing each fruit with a sterile needle. Five fruits of each cultivar were treated with sterile water as the mock-inoculated control treatment. Identical symptoms to those of the original fruit were observed only in the T. roseum-inoculated samples 5 to 7 days after using both inoculation procedures. Total DNA was extracted from a pure colony of the fungus growing on potato dextrose agar medium and used as template in PCR assays with the internal transcribed spacer (ITS)-4 (5′-TCCTCCGCTTATTGATATGC-3′) and ITS-5 (5′-GGAAGTAAAAGTCGTAACAAGG-3′) primer pair (2). A single amplicon of approximately 630 bp was observed and directly sequenced. Sequence analysis of the Brazilian isolate (GenBank No. JN081877) indicated identity levels of 99% with T. roseum isolates reported on Leucadendron xanthoconus in South Africa (GenBank No. EU552162) and isolates from strawberry fruits in South Korea (GenBank No. HM355750). However, phylogenetic analysis was unable to discriminate isolates of T. roseum from Passalora (GenBank No. EF432764) and Fusarium (GenBank No. GU183369) isolates, confirming the low genetic variability of the ITS region in Hypocreales (3). T. roseum has been reported to be infecting greenhouse tomatoes in the United States (4) and causing postharvest disease of tomatoes in Argentina (1). To our knowledge, this is the first report of T. roseum infecting greenhouse tomatoes in Brazil. References: (1) G. Dal Bello. Australas. Plant Dis. Notes 3:103, 2008. (2) N. L. Glass and G. C. Donaldson. Appl. Environ. Microbiol. 61:1323, 1995. (3) L. Lombard et al. Stud. Mycol. 66:31, 2010. (4) A. W. Welch, Jr. et al. Plant Dis. Rep. 59:255, 1975.

scholarly journals First Report of Pepper Fruit Rot Caused by Fusarium concentricum in China

Plant Disease ◽  
2013 ◽  
Vol 97 (12) ◽  
pp. 1657-1657 ◽  
Author(s):  
J. H. Wang ◽  
Z. H. Feng ◽  
Z. Han ◽  
S. Q. Song ◽  
S. H. Lin ◽  
...  
Keyword(s):  
Fusarium Species ◽  
Fruit Rot ◽  
Post Inoculation ◽  
Distilled Water ◽  
Conidial Suspension ◽  
Average Growth ◽  
First Report ◽  
Control Fruit ◽  
Pepper Fruit ◽  
Fruit Samples

Pepper (Capsicum annuum L.) is an important vegetable crop worldwide. Some Fusarium species can cause pepper fruit rot, leading to significant yield losses of pepper production and, for some Fusarium species, potential risk of mycotoxin contamination. A total of 106 diseased pepper fruit samples were collected from various pepper cultivars from seven provinces (Gansu, Hainan, Heilongjiang, Hunan, Shandong, Shanghai, and Zhejiang) in China during the 2012 growing season, where pepper production occurs on approximately 25,000 ha. Pepper fruit rot symptom incidence ranged from 5 to 20% in individual fields. Symptomatic fruit tissue was surface-sterilized in 0.1% HgCl2 for 1 min, dipped in 70% ethanol for 30 s, then rinsed in sterilized distilled water three times, dried, and plated in 90 mm diameter petri dishes containing potato dextrose agar (PDA). After incubation for 5 days at 28°C in the dark, putative Fusarium colonies were purified by single-sporing. Forty-three Fusarium strains were isolated and identified to species as described previously (1,2). Morphological characteristics of one strain were identical to those of F. concentricum. Aerial mycelium was reddish-white with an average growth rate of 4.2 to 4.3 mm/day at 25°C in the dark on PDA. Pigments in the agar were formed in alternating red and orange concentric rings. Microconidia were 0- to 1-septate, mostly 0-septate, and oval, obovoid to allantoid. Macroconidia were relatively slender with no significant curvature, 3- to 5-septate, with a beaked apical cell and a foot-shaped basal cell. To confirm the species identity, the partial TEF gene sequence (646 bp) was amplified and sequenced (GenBank Accession No. KC816735). A BLASTn search with TEF gene sequences in NCBI and the Fusarium ID databases revealed 99.7 and 100% sequence identity, respectively, to known TEF sequences of F. concentricum. Thus, both morphological and molecular criteria supported identification of the strain as F. concentricum. This strain was deposited as Accession MUCL 54697 (http://bccm.belspo.be/about/mucl.php). Pathogenicity of the strain was confirmed by inoculating 10 wounded, mature pepper fruits that had been harvested 70 days after planting the cultivar Zhongjiao-5 with a conidial suspension (1 × 106 spores/ml), as described previously (3). A control treatment consisted of inoculating 10 pepper fruits of the same cultivar with sterilized distilled water. The fruit were incubated at 25°C in a moist chamber, and the experiment was repeated independently in triplicate. Initially, green to dark brown lesions were observed on the outer surface of inoculated fruit. Typical soft-rot symptoms and lesions were observed on the inner wall when the fruit were cut open 10 days post-inoculation. Some infected seeds in the fruits were grayish-black and covered by mycelium, similar to the original fruit symptoms observed at the sampling sites. The control fruit remained healthy after 10 days of incubation. The same fungus was isolated from the inoculated infected fruit using the method described above, but no fungal growth was observed from the control fruit. To our knowledge, this is the first report of F. concentricum causing a pepper fruit rot. References: (1) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual. Blackwell Publishing, Ames, IA, 2006. (2) K. O'Donnell et al. Proc. Nat. Acad. Sci. USA 95:2044, 1998. (3) Y. Yang et al. 2011. Int. J. Food Microbiol. 151:150, 2011.

scholarly journals Plant extracts for controlling the post-harvest anthracnose of banana fruit

2013 ◽  
Vol 15 (4 suppl 1) ◽  
pp. 727-733 ◽  
Author(s):  
M.E.S. Cruz ◽  
K.R.F. Schwan-Estrada ◽  
E. Clemente ◽  
A.T. Itako ◽  
J.R. Stangarlin ◽  
...  
Keyword(s):  
Essential Oil ◽  
Disease Control ◽  
Disease Severity ◽  
Disease Incidence ◽  
Fruit Rot ◽  
Control Treatment ◽  
Distilled Water ◽  
Banana Fruit ◽  
Efficient Treatment ◽  
Post Harvest

In banana, fruit rot is incited by Colletotrichum musae which has been the most serious post-harvest disease of immature and mature fruit. The usual control by fungicides prohibited in many countries reduces their commercial value. Therefore, two experiments were conducted to evaluate the antimicrobial activity of alternative products to the synthetic fungicides. First, berries naturally infected by anthracnose were immersed into Azadirachta indica and citric extracts at 2 and 4% (v/v) for 3 minutes and stored for 11 days under environmental conditions. Next, other berries were immersed into essential oil emulsions of Allium sativum, Copaifera langsdorfii, Cinnamomum zeylanicum and Eugenia caryophyllata at 5% for 3 minutes but stored for 11 days. Berries immersed into distilled water were used as control-treatments. The percentage of disease incidence observed in the control-treatment was similar to the ones observed in the extract of A. indica at 2%. The control-treatment showed disease severity of 75.13% and the percentage of disease control was 20.85%. Fruit immersed into distilled water presented less effectiveness than the ones immersed into citric extracts, which promoted the highest effectiveness. Citric extract at 4% was the most efficient treatment because the disease incidence was 19.44%, the disease severity was 9.34% and the disease control was 90.16%. Less severity and, consequently, more disease control were achieved by immersing the berries into the emulsion of essential oil of A. sativum, followed by treatments with C. langsdorfii, E. caryophyllata and C. zeylanicum.

scholarly journals First Report of Alternaria alternata Causing a Leaf Spot on Philodendron ‘con-go’ in China

Plant Disease ◽  
2014 ◽  
Vol 98 (11) ◽  
pp. 1588-1588 ◽  
Author(s):  
Z. Zhou ◽  
Y. L. Li ◽  
C. Y. Yuan ◽  
P. L. Duan
Keyword(s):  
Alternaria Alternata ◽  
Leaf Spot ◽  
Its Region ◽  
Control Treatment ◽  
Distilled Water ◽  
Internal Transcribed Spacer Region ◽  
First Report ◽  
Potted Plants ◽  
Similar Disease ◽  
Residential District

Philodendron ‘con-go’ is widely cultivated indoors in China as an evergreen potted plant. In October 2013, a leaf spot on Philodendron ‘con-go’ was observed in the residential district of Luoyang (112.46° E, 34.62° N), Henan Province, China. The disease was characterized by oval-shaped, 10 to 20 × 25 to 55 mm, yellow to brown lesions with darker brown borders. Fifty potted plants were surveyed, and less than 2% of the leaves were infected. Lesions appeared mostly in old leaves. The symptomatic leaves affected on the plants' ornamental value, but had little impact on their health. Some lesions merged to form a large irregular lesion that could cover a whole leaf. Two infected leaves from one plant were selected randomly for the isolation of the pathogen. Lesions were cut into 1 cm2 pieces, soaked in 70% ethanol for 30 s, sterilized with 1% sodium hypochlorite for 5 min, then washed three times in sterilized distilled water. The pieces were incubated at 25°C on potato dextrose agar (PDA) for 4 to 5 days. A fungus was consistently isolated. Colonies of the fungus were deep green with white mycelium borders. Conidiophores were light brown with 2 to 4 septa. Conidia were obclavate, 14.6 to 49.1 × 8.3 to 16.4 μm, with a short beak, and with 1 to 5 transverse septa and 0 to 3 longitudinal septa, light brown to olive-brown. Based on morphology, the pathogen was identified as Alternaria alternata. Three isolates were selected randomly for further identification. To confirm pathogenicity, eight leaves of potted Philodendron ‘con-go’ plants were wounded with a sterile pin after wiping each leaf surface with 70% ethanol and washing each leaf with sterilized distilled water three times. The isolates were grown on PDA for 7 days and suspended in sterile distilled water to produce a final concentration of 2 × 105 spores/ml. A 5-μl drop of spore suspension was placed on each pin-wounded leaf. Each of three fungal isolates was inoculated on two leaves, and the control treatment (water inoculated) was done similarly on two leaves. The plants were placed in a growth chamber at 28°C with 80% relative humidity, 50 to 60 klx/m2 light intensity, and a 10-h photoperiod. After 7 days, lesions appeared on inoculated leaves, but the control leaves remained symptomless. Pathogenicity tests were repeated three times. Similar disease symptoms and re-isolation of A. alternata fulfilled Koch's postulates. To confirm the fungal identification, the rDNA of the internal transcribed spacer region in three isolates were amplified using primers ITS1 and ITS4 (1) and sequenced. The nucleotide sequence of the ITS region was submitted to GenBank under accession KJ829535 and showed 100% sequence identity with the strain A. alternata LPSC 1187 (KF753947.1). To our knowledge, this is the first report of a leaf spot of Philodendron ‘con-go’ by A. alternate in China. Reference: (1) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, San Diego, CA, 1990.

scholarly journals First Report of Oidium anamorph of Erysiphe hypophylla Causing Powdery Mildew on Leafy Lespedeza (Lespedeza cyrtobotrya) in Korea

Plant Disease ◽  
2013 ◽  
Vol 97 (2) ◽  
pp. 287-287 ◽  
Author(s):  
H. B. Lee
Keyword(s):  
Sequence Analysis ◽  
Powdery Mildew ◽  
Far East ◽  
Its Region ◽  
Agricultural Science ◽  
First Report ◽  
Rdna Its ◽  
Sand Control ◽  
Quercus Species ◽  
The World

Leafy lespedeza (Lespedeza cyrtobotrya Miq.) is a deciduous shrub in the pea family (Fabaceae) that occurs in areas of East Asia including Korea, China, and Japan. It has been commonly used as a fence plant and for sand control in Korea. In late October 2011, a powdery mildew disease was observed on leafy lespedeza in several areas near Gwangju River, Gwangju, Korea. Symptoms appeared late in October when temperature fluctuation was high. Major symptoms included scattered white powdery to cottony colonies on both surfaces of the leaves which spread to stems, causing a minor chlorosis and distortion. Conidia were formed singly on conidiophores with 2 to 4 (commonly 3) septa including basal septum, primary conidia ellipsoid, apex rounded to subtruncate, base truncate; and secondary conidia subcylindrical to oblong when mature, and ends truncate. The size was 26.4 to 43.2 (av. 35.1) × 11.2 to 13.2 (av. 11.3) μm. Conidiophores were erect, cylindrical, wider at apex than foot cell, and straight or slightly flexuous in foot cells. The size was 60.1 to 81.3 (av. 78.1) × 6.2 to 12.1 (av. 8.3) μm. Chasmothecia were not observed. Morphologically, the conidia and conidiophores of our strain (EML-LCPW1) were very similar to those of Erysiphe hypophylla (syn. Microsphaera hypophylla) (4). From extracted genomic DNA, the internal transcribed spacer (ITS) region inclusive of 5.8S and 28S rDNA were amplified with ITS1 (5′-TCCGTAGGTGAACCTGCGG-3′), LR5F (5′-GCTATCCTGAGGGAAAC-3′), LROR (5′-ACCCGCTGAACTTAAGC-3′), and LR5F primer sets, respectively. Based on the morphology and ITS rDNA sequence analysis, the fungus was identified as E. hypophylla. rDNA ITS and 28S homologies of the fungus (EML-LCPW1, GenBank Accession Nos. JX512557 and JX512558) represented 100% (771/771) and 100% (775/775) identity values with E. hypophylla (AB292712 and AB292716, respectively) via NCBI BLASTn search of each isolate. The rDNA ITS (JX512557) and 28S (JX512558) sequence analysis revealed that the causal fungus matched E. hypophylla, forming a HypophyllaAlphitoides clade as Takamatsu et al. suggested that E. hypophylla is conspecific to E. alphitoides (3). So far, it has been known that E. communis, E. glycines var. lespedezae, and E. lespedezae cause powdery mildews on Lespedeza plants in the world (1). In Korea, only one Erysiphe species, E. lespedezae (= E. pisi), has been reported to cause powdery mildew on Lespedeza plants including L. bicolor and L. cyrtobotrya (2). In addition, 10 records with respect to Oidium sp. have been found on Lespedeza spp., including L. cyrtobotrya from Japan and L. chinensis from China (1). However, powdery mildew on Lespedeza plants, including leafy lespedeza caused by E. hypophylla, has not been reported in Korea or elsewhere in the world. This fungus has been reported in association with numerous oak (Quercus) species in nearby countries such as China and Russia (Far East), showing that it may be a potential source of inoculum in Korea as well. To our knowledge, this is the first report of Oidium anamorph of E. hypophylla on leafy lespedeza (L. cyrtobotrya) in Korea. References: (1) D. F. Farr and A. Y. Rossman. Fungal Databases, Syst. Mycol. Microbiol. Lab., ARS, USDA. Retrieved from http://nt.ars-grin.gov/fungaldatabases/ , October 9, 2012. (2) H. D. Shin. Page 320 in: Erysiphaceae of Korea. National Institute of Agricultural Science & Technology, Suwon, Korea, 2000. (3) S. Takamatsu et al. Mycoscience 47:367, 2006. (4) S. Takamatsu et al. Mycol. Res. 111:809, 2007.

scholarly journals First Report of Anthracnose Caused by Colletotrichum liaoningense on Trichosanthes kirilowii in China

Plant Disease ◽  
2021 ◽  
Author(s):  
Lixin Zhang ◽  
Yifan Lin ◽  
Lei Zhang ◽  
Xia Wang ◽  
Jianghua Song
Keyword(s):  
Morphological Characteristics ◽  
Its Region ◽  
Culture Collection ◽  
Central China ◽  
Fruit Rot ◽  
First Report ◽  
Plastic Bags ◽  
Fruit Samples ◽  
Pathogenicity Tests ◽  
Trichosanthes Kirilowii

Trichosanthes kirilowii Maxim (T. kirilowii) is widely grown in central China for its medicinal and edible value. In August 2020, an anthracnose-like disease was observed on fruit of T. kirilowii (cv. Wanlou9) in four fields (0.9 ha) located in Taihu county, Anhui Province of China. Approximately 60% of the T. kirilowii plants were affected in the fields. The symptoms initially consisted of small off-white necrotic spots, and later became larger, irregular gray necrotic lesions on green fruit, causing fruit rot and sometimes fruit drop. More than 10 symptomatic fruits were sampled, and small pieces of diseased tissue were surface sterilized in 0.1% HgCl2 for 2 min, 75% ethanol for 45 s, rinsed three times with sterile distilled water, then placed on potato dextrose agar (PDA) and incubated at 25℃in the dark. A fungus was consistently (80%) isolated from symptomatic fruit samples. Aerial mycelia were light gray, and radially black with white in reverse medium. Conidia were rarely produced on PDA, but prolific on water agar. The conidia were cylindrical to clavate, both ends rounded, had obvious circular granule in the center, and ranged from 14.6 to 19.9 μm × 5.4 to 7.3 μm. The morphological characteristics were similar to the descriptions of C. liaoningense by Diao et al. (2017). For molecular identification, representative isolates LG5-4 and LG9-6 were selected. Genomic DNA was extracted, and the internal transcribed spacer (ITS) region, actin (ACT), glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and β-tubulin (TUB2) genes were amplified by PCR (White et al. 1990; Duan et al. 2018), and sequenced bidirectionally. A BLAST search of GenBank revealed the ACT and TUB sequences had 95.83% (KP890097), 99.20%, 95.33% (KP890111) and 99.84%, respectively, to C. liaoningense CAUOS2. A phylogenetic analysis was conducted using MEGA7 based on concatenated sequences of the four genes, indicating that the isolates were closely clustered with reference strains of C. liaoningense (98% bootstrap value). The two strains were deposited in the China General Microbiological Culture Collection Center as CGMCC3.20344 and CGMCC3.20345, and their sequences deposited in GeneBank (Accession nos. MW082811-12, MW117926-31), respectively. Pathogenicity tests were conducted on healthy fruit of T. kirilowii (cv. Wanlou9) using the wound inoculation by pinpricking and droplet (106 conidia/mL) on fruit surface. The experiments were done with three fruit per isolate (LG5-4 and LG9-6), and replicated three times. The controls were inoculated with sterile water. The fruit were covered with plastic bags and kept in a chamber (>90% RH, 28 to 30°C) for 14 days. Typical symptoms of yellow-brown lesions appeared 14 days after inoculation. No symptoms were observed on the controls. The fungus was re-isolated from the diseased tissues and identified as C. liaoningense by sequencing of the four genes, confirming Koch’s postulates. C. liaoningense has been reported to cause anthracnose of mango and chili in China (Diao et al. 2017; Li et al. 2019). To our knowledge, this is the first report of C. liaoningense causing anthracnose on T. kirilowii. Due to cultivation of T. kirilowii in the region, further studies are required to develop management strategy of this disease.

scholarly journals First Report of Pythium recalcitrans Causing Cavity Spot of Carrot in Michigan

Plant Disease ◽  
2013 ◽  
Vol 97 (7) ◽  
pp. 991-991 ◽  
Author(s):  
X. H. Lu ◽  
H. H. Jiang ◽  
J. J. Hao
Keyword(s):  
Dna Sequences ◽  
Morphological Characteristics ◽  
Its Region ◽  
Control Treatment ◽  
Distilled Water ◽  
Plastic Container ◽  
Daucus Carota L ◽  
Cavity Spot ◽  
Pure Cultures ◽  
Cox 2

During a survey of carrot (Daucus carota L.) cavity spot in Michigan in September 2010, carrot roots with typical cavity spot symptoms were collected from production fields in Fremont Co. The lesions were excised from infected roots, surface-disinfested with 0.62% NaClO for 3 min, rinsed in sterilized, distilled water three times, cut into 0.5 cm long pieces, and then plated on water agar (WA) amended with carbendazim (10 μg/ml), ampicillin (50 μg/ml), rifampicin (50 μg/ml), and pentachloronitrobenzene (10 μg/ml) (cumulatively referred to as CARP). Plates were incubated at 22 ± 1°C in the dark for 3 days. Pure cultures of the isolates were obtained by transferring a single hyphal tip of each colony to potato dextrose agar (PDA) amended with CARP. Among the 33 isolates obtained, M2-05 was identified as a Pythium sp. that differed from the known cavity spot pathogens of carrot. The isolate has spherical hyphal swellings but no other distinguishing morphological characteristics. M2-05 was further classified by analyzing the partial sequences of four genes: the internal transcribed spacer (ITS) region of ribosomal DNA, beta-tubulin (β-tub), cytochrome c oxidase subunit 2 (cox 2), and NADH dehydrogenase subunit 1 (nadh 1) (1,3). A BLAST search of these sequences for M2-05 was conducted using the nucleotide database of GenBank, resulting in 100% similarity to all four sequenced genes of P. recalcitrans (2). The DNA sequences of M2-05 were deposited in GenBank (JQ734349, JQ734229, JQ734289, and JQ734409 for ITS, β-tub, cox 2, and nadh 1, respectively). Koch's postulates were conducted by inoculating mature carrot roots (cv. Nantindo) with mycelial plugs (4 mm in diameter) cut from the margin of actively growing colonies of M2-05 on PDA plates. Two mycelial plugs were placed on each carrot root at 3-cm intervals, with the mycelial side facing the root; and two non-colonized agar plugs were placed similarly for the non-inoculated control treatment. In comparison, carrot roots also were inoculated with an isolate of each of P. sulcatum and P. violae using the same method. There were four replicate carrot roots inoculated for each isolate and each of the control treatments. The inoculated roots were placed on a plastic grid (7 mm in height) in a closed plastic container, with moist paper towels underneath the grids. The container was incubated in the dark at 22 ± 1°C, and the roots were sprayed gently daily with sterilized, distilled water to maintain high humidity. Brown lesions were observed on all inoculated carrot roots 5 days after inoculation. The lesions measured 0.68 ± 0.48, 1.20 ± 0.71, and 0.56 ± 0.31 mm2 averaged over all eight lesions for the isolates of P. recalcitrans, P. sulcatum, and P. violae, respectively. Symptomatic tissues from the inoculated roots were excised and incubated on WA-CARP plates, and the culture from each lesion confirmed as the isolates inoculated using the same molecular methods described above. The carrot tissue under the control agar plugs remained symptomless, and no Pythium was recovered from the control roots. P. recalcitrans was described in 2008 as infecting roots of Beta vulgaris and Vitis vinifera (2). To our knowledge, this is the first published report of P. recalcitrans naturally infecting carrot roots, not only in Michigan, but anywhere in the world. References: (1) L. Kroon et al. Fungal. Genet. Biol. 41:766, 2004. (2) E. Moralejo et al. Mycologia 100:310, 2008. (3) N. O. Villa et al. Mycologia 98:410, 2006.

Phylogeny and taxonomy of the family Arthrodermataceae (dermatophytes) using sequence analysis of the ribosomal ITS region

1999 ◽  
Vol 37 (2) ◽  
pp. 105-114 ◽  
Author(s):  
Y. GRAser ◽  
M. EL Fari ◽  
R. Vilgalys ◽  
A. F. A. Kuijpers ◽  
G. S. DE Hoog ◽  
...  
Keyword(s):  
Sequence Analysis ◽  
Its Region ◽  
The Family

scholarly journals Veronica sibirica Leaf Spots Caused by Phacellium veronicae, a New Disease in China

Plant Disease ◽  
2013 ◽  
Vol 97 (12) ◽  
pp. 1662-1662 ◽  
Author(s):  
Q. R. Bai ◽  
S. Han ◽  
Y. Y. Xie ◽  
J. Gao ◽  
Y. Li
Keyword(s):  
Morphological Characteristics ◽  
Its Region ◽  
Control Treatment ◽  
Perennial Herb ◽  
Conidial Suspension ◽  
New Disease ◽  
Medical College ◽  
Leaf Spots ◽  
Plastic Bags ◽  
Insect Bites

Veronica sibirica (Veronicastrum sibiricum) is an erect perennial herb, an ornamental, and a traditional Chinese medicine plant distributed mostly in northeastern, northern, and northwestern China. It has dehumidifying and detoxifying properties, and is mainly used for the treatment of cold, sore throat, mumps, rheumatism, and insect bites (4). In June 2008 through 2012, leaf spots of V. sibirica were observed in the Medicinal Herb Garden of Jilin Agricultural University (43°48′N, 125°23′E) and the medicinal plantations of Antu County (43°6′N, 128°53′E), Jilin Province. Leaf spots were amphigenous, subcircular, angular-irregular, brown, and 1 to 10 mm in diameter; they occasionally merged into a larger spot with an indefinite margin or with a pale center and dark border. Pale conidiomata were hypophyllous and scattered on the spots. The conidiophores were 100 to 400 μm high and clustered together to form synnemata 20 to 50 μm in diameter, which splayed out apically and formed loose to dense capitula. Conidiophores occasionally emerged through the stomata individually and produced conidia on the surface of the infected leaves. The conidiogenous cell terminal was geniculate-sinuous with somewhat thickened and darkened conidial scars. Conidia were solitary or catenulate, ellipsoid-ovoid or subcylindric-fusiform, hyaline and spinulose, 4.01 to 7.18 × 11.16 to 20.62 μm with obtuse to somewhat attenuated ends, and slightly thickened, darkened hila. Six isolates were obtained from necrotic tissue of leaf spots and cultured on potato dextrose agar at 25°C. After incubation for 14 days, colony surfaces were white to pinkish. The colony diameter increased by 12 mm after 21 days' incubation. Hyphae were hyaline, septate, and branched. Conidiophores grew individually or fascicularly. The symptoms and morphological characteristics were consistent with previous descriptions (1,2), and the fungus was identified as Phacellium veronicae (Pass.) (U. Braun 1990). The internal transcribed spacer (ITS) region of the nuclear rDNA was amplified using primers ITS4/ITS5 (3). The ITS was identical among all six isolates (HE995799) and 98% identical to that of P. veronicae (JQ920427, HQ690097). Pathogenicity was confirmed by spraying five 1-year-old V. sibirica seedlings with a conidial suspension (106 conidia/ml) of each isolate and five seedlings with sterile water as a control treatment. Plants were grown in the greenhouse at 20 to 25°C and were covered with plastic bags to maintain humidity on the foliage for 72 h. After 15 days, the same symptoms appeared on the leaves as described earlier for the field-grown plants; the control plants remained healthy. The same fungus was reisolated from the leaf spots of inoculated plants. Currently, the economic importance of this disease is limited, but it may become a more significant problem, as the cultivated area of V. sibirica is increasing. To our knowledge, although P. veronicae was recorded on the other species of Veronica (V. austriaca, V. chamaedrys, V. grandis, V. longifolia, V. paniculata, and V. spicata ssp. incana) in Europe (Germany, Denmark, Ireland, Romania) and V. wormskjoldii in North America (Canada) (1), this is the first report of V. sibirica leaf spots caused by P. veronicae in the world, and it is a new disease in China. References: (1) U. Braun. A monograph of Cercosporella, Ramularia and allied genera (phytopathogenic Hyphomycetes) 2, IHW-Verlag, Germany, 1998. (2) U. Braun. Nova Hedwigia 50:499, 1990. (3) D. E. L. Cooke et al. Mycol. Res. 101:667, 1997. (4) Jiangsu New Medical College. Dictionary of Chinese Materia Medica. Shanghai: Shanghai Scientific and Technical Publishers, China, 1977.

scholarly journals First Report of Flyspeck Caused by Zygophiala wisconsinensis on Sweet Persimmon Fruit in Korea

Plant Disease ◽  
2011 ◽  
Vol 95 (5) ◽  
pp. 616-616 ◽  
Author(s):  
J. Kim ◽  
O. Choi ◽  
J.-H. Kwon
Keyword(s):  
Disease Incidence ◽  
Morphological Characteristics ◽  
Its Rdna ◽  
Control Treatment ◽  
Diospyros Kaki ◽  
Distilled Water ◽  
First Report ◽  
Persimmon Fruit ◽  
Fungal Isolates ◽  
Agar Disc

Sweet persimmon (Diospyros kaki L.), a fruit tree in the Ebenaceae, is cultivated widely in Korea and Japan, the leading producers worldwide (2). Sweet persimmon fruit with flyspeck symptoms were collected from orchards in the Jinju area of Korea in November 2010. The fruit had fungal clusters of black, round to ovoid, sclerotium-like fungal bodies with no visible evidence of a mycelial mat. Orchard inspections revealed that disease incidence ranged from 10 to 20% in the surveyed area (approximately 10 ha) in 2010. Flyspeck symptoms were observed on immature and mature fruit. Sweet persimmon fruit peels with flyspeck symptoms were removed, dried, and individual speck lesions transferred to potato dextrose agar (PDA) and cultured at 22°C in the dark. Fungal isolates were obtained from flyspeck colonies on 10 sweet persimmon fruit harvested from each of three orchards. Fungal isolates that grew from the lesions were identified based on a previous description (1). To confirm identity of the causal fungus, the complete internal transcribed spacer (ITS) rDNA sequence of a representative isolate was amplified and sequenced using primers ITS1 and ITS4 (4). The resulting 552-bp sequence was deposited in GenBank (Accession No. HQ698923). Comparison with ITS rDNA sequences showed 100% similarity with a sequence of Zygophiala wisconsinensis Batzer & Crous (GenBank Accession No. AY598855), which infects apple. To fulfill Koch's postulates, mature, intact sweet persimmon fruit were surface sterilized with 70% ethanol and dried. Three fungal isolates from this study were grown on PDA for 1 month. A colonized agar disc (5 mm in diameter) of each isolate was cut from the advancing margin of a colony with a sterilized cork borer, transferred to a 1.5-ml Eppendorf tube, and ground into a suspension of mycelial fragments and conidia in a blender with 1 ml of sterile, distilled water. The inoculum of each isolate was applied by swabbing a sweet persimmon fruit with the suspension. Three sweet persimmon fruit were inoculated per isolate. Three fruit were inoculated similarly with sterile, distilled water as the control treatment. After 1 month of incubation in a moist chamber at 22°C, the same fungal fruiting symptoms were reproduced as observed in the orchards, and the fungus was reisolated from these symptoms, but not from the control fruit, which were asymptomatic. On the basis of morphological characteristics of the fungal colonies, ITS sequence, and pathogenicity to persimmon fruit, the fungus was identified as Z. wisconsinensis (1). Flyspeck is readily isolated from sweet persimmon fruit in Korea and other sweet persimmon growing regions (3). The exposure of fruit to unusual weather conditions in Korea in recent years, including drought, and low-temperature and low-light situations in late spring, which are favorable for flyspeck, might be associated with an increase in occurrence of flyspeck on sweet persimmon fruit in Korea. To our knowledge, this is the first report of Z. wisconsinensis causing flyspeck on sweet persimmon in Korea. References: (1) J. C. Batzer et al. Mycologia 100:246, 2008. (2) FAOSTAT Database. Retrieved from http://faostat.fao.org/ , 2008. (3) H. Nasu and H. Kunoh. Plant Dis. 71:361, 1987. (4) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, Inc., New York, 1990.

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