scholarly journals First Report of Occurrence of Benomyl Resistance in Botrytis cinerea Isolates on Raspberry in Serbia

Plant Disease ◽  
2010 ◽  
Vol 94 (4) ◽  
pp. 486-486 ◽  
Author(s):  
B. Tanović ◽  
M. Ivanović
Keyword(s):  
Botrytis Cinerea ◽  
Pcr Amplification ◽  
Rubus Idaeus ◽  
Fruit Rot ◽  
Single Spore ◽  
Thiophanate Methyl ◽  
First Report ◽  
Benomyl Resistance ◽  
Development Of Resistance ◽  
Resistant Strains

Botrytis fruit rot, caused by Botrytis cinerea, is one of the major diseases limiting production of raspberries (Rubus idaeus) in Serbia. Yield losses in commercial fields can exceed 50%, especially during periods of rainy, wet weather before harvest. Development of resistance to fungicides with site-specific modes of action is a serious problem in the control of B. cinerea worldwide. To insure the longest possible useful life of a fungicide, an early detection of shifts of sensitivity in pathogen population is crucial (1). The goal of this study was to evaluate sensitivity of B. cinerea isolates from commercial raspberry fields in Serbia to several fungicides that are frequently used: vinclozolin, benomyl, pyrimethanil, and fenhexamid. Initial isolation was done from sporulating berries during harvest. Single-spore isolates were identified based on colony and conidial morphology and by PCR amplification of an expected 0.7-kbp DNA fragment using B. cinerea-specific primer pair C729+/729- (3). Sensitivity of 130 isolates from six localities (20 to 30 isolates per locality) was determined on potato dextrose agar (PDA) amended with fungicides at discriminatory concentrations (1 and 10 mg/liter). Fungicides were suspended in sterile distilled water and added to autoclaved media that had cooled to 50°C. Inverted mycelial plugs (10-mm diameter), which had been cut from the edge of 4-day-old colonies on PDA, were placed on fungicide amended media and incubated for 48 h at 20°C. Treatments were replicated four times and the experiment repeated once. Strain SAS 56, which is sensitive to benzimidazoles and dicarboximides, and strain SAS 405, which is resistant to these fungicide classes, originating from German Collection of Microorganisms and Cell Cultures, were used as standards in the experiment. Isolates that did not grow at 1 mg/liter were designated as sensitive, those that grew at 10 mg/liter were considered highly resistant, and those that grew at 1 mg/liter but not at 10 mg/liter were classified as weakly resistant to all fungicides tested. Values of EC50 for all highly resistant strains were determined in radial growth experiments on PDA supplemented with a range of concentrations (5,000, 2,500, 1,000, and 500 mg/liter) of benomyl or thiophanate-methyl, according to the method described by Leroux and Gredt (2). All tested isolates were sensitive to vinclozolin, pyrimethanil, and fenhexamid. Nine of 130 isolates were highly resistant to benomyl with EC50 values between 1,056 and 1,523 mg/liter. The reference strain SAS 56 had an EC50 value of 0.17 mg/liter, compared to an EC50 value for SAS 405 strain of 1,548 mg/liter. All benomyl resistant isolates were also resistant to thiophanate-methyl and EC50 values ranged from 2,328 to 7,699 mg/liter. To our knowledge, this is the first report of benomyl resistance in isolates of B. cinerea on raspberry in Serbia. References: (1) H. Ishii. Jarq 40:205, 2006. (2) P. Leroux and M. Gredt. Page 1 in: Laboratoire de Phytopharmacie, INRA, Versailles, 1972. (3) S. Rigotti et al. FEMS Microbiol. Lett. 209:169, 2002.

scholarly journals Resistance of Botrytis cinerea Isolates from Vegetable Crops to Anilinopyrimidine, Phenylpyrrole, Hydroxyanilide, Benzimidazole, and Dicarboximide Fungicides

Plant Disease ◽  
2007 ◽  
Vol 91 (4) ◽  
pp. 407-413 ◽  
Author(s):  
C. K. Myresiotis ◽  
G. S. Karaoglanidis ◽  
K. Tzavella-Klonari
Keyword(s):  
Regression Analysis ◽  
Botrytis Cinerea ◽  
Linear Regression Analysis ◽  
Cross Resistance ◽  
Vegetable Crops ◽  
Single Spore ◽  
Development Of Resistance ◽  
Greenhouse Vegetable ◽  
Resistant Strains ◽  
First Time

During February 2005, 55 single-spore isolates of Botrytis cinerea were collected at the end of the season from vegetable crops grown in 18 greenhouses on the island of Crete, Greece. They were tested for sensitivity to the anilinopyrimidine fungicides pyrimethanil and cyprodinil, the hydroxyanilide fungicide fenhexamid, the phenylpyrrole fungicide fludioxonil, the dicarboximide fungicide iprodione, and the benzimidazole fungicide carbendazim. Results of the study showed the existence of benzimidazole- and dicarboximide-resistant strains at frequencies of 61.8 and 18%, respectively. Moreover, for first time, the development of resistance to anilinopyrimidine fungicides by B. cinerea was detected in greenhouse vegetable crops on the island of Crete. High resistance frequencies of 49.1 and 57.4% were observed for pyrimethanil and cyprodinil, respectively. In addition, one isolate was found to be resistant to the hydroxyanilide fungicide fenhexamid, while no strains resistant to the phenylpyrrole fungicide were detected. Among the 55 isolates tested, 13 were resistant only to carbendazim, 6 were resistant only to anilinopyrimidines, 3 were resistant to both benzimidazoles and dicarboximides, 17 were resistant to both benzimidazoles and anilinopyrimidines, 6 were resistant to both dicarboximides and anilinopyrimidines, 1 was simultaneously resistant to benzimidazoles, dicarboximides, and anilinopyrimidines, 1 was resistant to both anilinopyrimidines and hydroxyanilides, and 8 were sensitive to all fungicides tested. A strong cross-resistance relationship was found between the two anilinopyrimidine fungicides tested when log transformed EC50 values of the isolates were subjected to a linear regression analysis (r = 0.71). Despite the detection of several phenotypes with simultaneous resistance to chemically unrelated active ingredients, in none of the remaining possible fungicide pairs was there observed any kind of cross-resistance relationship.

scholarly journals First Report of Fruit Blotch on Plum caused by Fusarium fujikuroi in China

Plant Disease ◽  
2021 ◽  
Author(s):  
Haijiang Long ◽  
Xianhui Yin ◽  
Zhibo Zhao ◽  
Youhua Long ◽  
Juan Fan ◽  
...  
Keyword(s):  
Rna Polymerase Ii ◽  
Sequence Data ◽  
Apical Cell ◽  
Pcr Amplification ◽  
Fruit Rot ◽  
Guizhou Province ◽  
Universal Primers ◽  
Fusarium Fujikuroi ◽  
Single Spore ◽  
First Report

Plum is commercially cultivated worldwide for the rich nutrient in its fruit. In May 2019, plum with symptoms of fruit rot were collected from fields located in Liuma town, Guizhou Province, China. The incidence of the disease varied from 10 to 20%, which was observed in 15 plum orchards (18 hectares) surveyed. Estimated yield loss was~5 to 10% for each field. Diseased fruits showed deformity, wilting and sunken lesions, and subsequenly became melanized and rotted. Diseased tissues were surface disinfected with 70% ethanol for 45 s and rinsed with sterile distilled water three times. Four morphologically similar colonies with white fluffy aerial mycelium and a reddish pigment were obtained after 3 days incubation on potato dextrose agar (PDA) at 25°C. Four single-spore isolates produced conidia with 1 to 2 septa that were sickle-shaped, thin-walled with a tapering and curved apical cell, measuring 15.6 to 29.6 × 4.8 to 8.7 μm (average 19.5×5.9 μm, n=50). Based on the cultural and conidial morphology, the isolates were identified as Fusarium (Mun et al. 2012; Leslie and Summerell 2006). DNA of two isolates was extracted using the Ezup Column Fungal Genomic DNA Extraction Kit (Sangon Bioengineering Shanghai, LTD.). To confirm the morphological diagnosis, DNA sequence data from three loci were obtained. PCR amplification was carried out with universal primers ITS1/ITS4 (White et al. 1990), translation elongation factor (EF-1α), EF1-H (5′-ATGGGTAAGGAAGACAAGAC-3′) and EF2-T (5′-GGAAGTACCAGTGATCATGTT-3′) (O’Donnell et al. 1998) and the second largest subunit of RNA polymerase II (RPB2), 5F2(5′-GGGGWGAYCAGAAGAAGGC-3′) and 7cR (5′-CCCATRGCTTGYTTRCCCAT-3′) (O’Donnell et al. 2007). Primers ITS1 and ITS4 produced a 559-bp amplicon (GenBank accession. MW085028). BLAST analysis showed 100% sequence identity to sequences of several species, deposited in GenBank, including F. fujikuroi. The EF-1α sequence (MW086868) was 100% identical to that of Fusarium fujikuroi (MN193860.1). The RPB2 primers amplified a fragment (MW086869) that was 99.9% identical to that of F. fujikuroi (MN193888.1). The BLASTn results based on the partial EF-1α and RPB2 sequences suggest isolate HJGF1 is F. fujikuroi. A pathogenicity assay was conducted using an agar disk inoculation method on plum. Fruits were stab inoculated with HJGF1 by piercing 1-mm at 3 points using a sterile needle, and fruits were mock inoculated with sterile PDA, each fruit was inoculated with three disks. (Fig. 1). The treated fruit were maintained in a growth chamber with 90% relative humidity at 25°C, and a daily 12-h photoperiod. After 5 days, the artificially inoculated fruit showed blotches with sunken lesions similar to those observed in the orchards, whereas no symptoms were observed on the control fruit. The experiment was repeated twice with similar results. F. fujikuroi was reisolated from infected tissues and confirmed by sequence analysis. To our knowledge, this is the first report of F. fujikuroi causing fruit blotch of plum in China. Considering the economic importance of plum in China and throughout the world, F. fujikuroi may be an emerging problem for plum cultivation. Thus, further study of fruit blotch of plum is warranted.

scholarly journals First Report of a Fruit Rot of Pumpkin Caused by Acidivorax avenae subsp. citrulli in Georgia

Plant Disease ◽  
1999 ◽  
Vol 83 (2) ◽  
pp. 199-199 ◽  
Author(s):  
D. B. Langston ◽  
R. D. Walcott ◽  
R. D. Gitaitis ◽  
F. H. Sanders
Keyword(s):  
Polyclonal Antibodies ◽  
Pcr Amplification ◽  
Tween 80 ◽  
Soft Rot ◽  
Fruit Rot ◽  
Identification System ◽  
Banding Patterns ◽  
First Report ◽  
Microbial Identification ◽  
Necrotic Spots

In September 1998, a fruit rot was reported affecting pumpkin (Cucurbita pepo) in a commercial field in Terrell Co., Georgia. Symptoms on the surface of fruit occurred as round, necrotic spots or cracks a few millimeters in diameter. With age, the tissue surrounding these lesions became soft and wrinkled. A soft rot expanded into the flesh of the pumpkin, originating from the lesions observed on the surface. In time, infected pumpkins totally collapsed. V-shaped, necrotic lesions occurred at the margin of the leaf and extended inward toward the mid-rib. Samples were collected from the field and bacteria were isolated from fruit and leaf lesions onto King's medium B (1). The bacterium isolated was rod shaped, gram negative, nonflourescent, oxidase positive, Tween 80 positive, carboxymethyl cellulose positive, β-OH butyrate positive, and malonate negative. The bacterium reacted positively with polyclonal antibodies specific for the watermelon fruit blotch pathogen Acidivorax avenae subsp. citrulli and was identified as A. avenae subsp. citrulli by MIDI (Microbial Identification System, Newark, DE) according to statistical analysis of fatty acid data. Results from polymerase chain reaction (PCR) amplification of the bacterium isolated from pumpkin yielded 360-bp fragments that, when digested with the restriction enzyme HaeIII, had DNA banding patterns identical to those of stock A. avenae subsp. citrulli DNA. Koch's postulates were completed successfully with 2-week-old watermelon seedlings. This is the first report of A. avenae subsp. citrulli causing fruit rot of pumpkin in Georgia. Reference: (1) E. O. King et al. J. Lab. Clin. Med. 44:301, 1954.

scholarly journals First Report of Leaf Spot Caused by Botrytis cinerea on Cardamine hupingshanensis in China

Plant Disease ◽  
2021 ◽  
Author(s):  
Jun Guo ◽  
Jin Chen ◽  
Zhao Hu ◽  
Jie Zhong ◽  
Jun Zi Zhu
Keyword(s):  
Botrytis Cinerea ◽  
Morphological Characteristics ◽  
Gray Mold ◽  
Hunan Province ◽  
Conidial Suspension ◽  
Heat Shock Protein 60 ◽  
Basal Cells ◽  
Single Spore ◽  
Internal Transcribed Spacer Region ◽  
First Report

Cardamine hupingshanensis is a selenium (Se) and cadmium (Cd) hyperaccumulator plant distributed in wetlands along the Wuling Mountains of China (Zhou et al. 2018). In March of 2020, a disease with symptoms similar to gray mold was observed on leaves of C. hupingshanensis in a nursery located in Changsha, Hunan Province, China. Almost 40% of the C. hupingshanensis (200 plants) were infected. Initially, small spots were scattered across the leaf surface or margin. As disease progressed, small spots enlarged to dark brown lesions, with green-gray, conidia containing mold layer under humid conditions. Small leaf pieces were cut from the lesion margins and were sterilized with 70% ethanol for 10 s, 2% NaOCl for 2 min, rinsed with sterilized distilled water for three times, and then placed on potato dextrose agar (PDA) medium at 22°C in the dark. Seven similar colonies were consistently isolated from seven samples and further purified by single-spore isolation. Strains cultured on PDA were initially white, forming gray-white aerial mycelia, then turned gray and produced sclerotia after incubation for 2 weeks, which were brown to blackish, irregular, 0.8 to 3.0 × 1.2 to 3.5 mm (n=50). Conidia were unicellular, globose or oval, colourless, 7.5 to 12.0 × 5.5 to 8.3 μm (n=50). Conidiophores arose singly or in group, straight or flexuous, septate, brownish to light brown, with enlarged basal cells, 12.5 to 22.1 × 120.7 to 310.3 μm. Based on their morphological characteristics in culture, the isolates were putatively identified as Botrytis cinerea (Ellis 1971). Genomic DNA of four representative isolates, HNSMJ-1 to HNSMJ-4, were extracted by CTAB method. The internal transcribed spacer region (ITS), glyceraldehyde-3-phosphate dehydrogenase gene (G3PDH), heat-shock protein 60 gene (HSP60), ATP-dependent RNA helicaseDBP7 gene (MS547) and DNA-dependent RNA polymerase subunit II gene (RPB2) were amplified and sequenced using the primers described previously (Aktaruzzaman et al. 2018) (MW820311, MW831620, MW831628, MW831623 and MW831629 for HNSMJ-1; MW314722, MW316616, MW316617, MW316618 and MW316619 for HNSMJ-2; MW820519, MW831621, MW831627, MW831624 and MW831631 for HNSMJ-3; MW820601, MW831622, MW831626, MW831625 and MW831630 for HNSMJ-4). BLAST searches showed 99.43 to 99.90% identity to the corresponding sequences of B. cinerea strains, such as HJ-5 (MF426032.1, MN448500.1, MK791187.1, MH727700.1 and KX867998.1). A combined phylogenetic tree using the ITS, G3PDH, HSP60 and RPB2 sequences was constructed by neighbor-joining method in MEGA 6. It revealed that HNSMJ-1 to HNSMJ-4 clustered in the B. cinerea clade. Pathogenicity tests were performed on healthy pot-grown C. hupingshanensis plants. Leaves were surface-sterilized and sprayed with conidial suspension (106 conidia/ mL), with sterile water served as controls. All plants were kept in growth chamber with 85% humidity at 25℃ following a 16 h day-8 h night cycle. The experiment was repeated twice, with each three replications. After 4 to 7 days, symptoms similar to those observed in the field developed on the inoculated leaves, whereas controls remained healthy. The pathogen was reisolated from symptomatic tissues and identified using molecular methods, confirming Koch’s postulates. B. cinerea has already been reported from China on C. lyrate (Zhang 2006), a different species of C. hupingshanensis. To the best of our knowledge, this is the first report of B. cinerea causing gray mold on C. hupingshanensis in China and worldwide. Based on the widespread damage in the nursery, appropriate control strategies should be adopted. This study provides a basis for studying the epidemic and management of the disease.

scholarly journals Resistance in Colletotrichum siamense From Peach and Blueberry to Thiophanate-Methyl and Azoxystrobin

Plant Disease ◽  
2015 ◽  
Vol 99 (6) ◽  
pp. 806-814 ◽  
Author(s):  
Meng-Jun Hu ◽  
Anja Grabke ◽  
Madeline E. Dowling ◽  
Helen J. Holstein ◽  
Guido Schnabel
Keyword(s):  
South Carolina ◽  
Field Resistance ◽  
Fruit Rot ◽  
Nucleotide Sequence Analysis ◽  
Cytb Gene ◽  
Single Spore ◽  
Peach Fruit ◽  
Thiophanate Methyl ◽  
Colletotrichum Siamense ◽  
Commercial Operation

Anthracnose fruit rot was observed in some late-season peach cultivars in South Carolina in the 2012 and 2013 production seasons as well as increased anthracnose leaf spot of blueberry in a commercial operation of the same state in 2012. Single-spore isolates of Colletotrichum siamense were either sensitive or resistant to both thiophanate-methyl and azoxystrobin with the concentration of the fungicide at which fungal development is inhibited by 50% of ≥100 μg/ml. Resistant isolates revealed the E198A mutation in β-tubulin and the G143A mutation in cytochrome b. Nucleotide sequence analysis of the complete CYTB gene from genomic DNA of C. siamense isolates revealed an intronless genotype (CsI) and a genotype revealing two introns (CsII) at amino acid positions 131 and 164. Resistance to thiophanate-methyl or azoxystrobin was not found in isolates of C. fructicola collected from peach fruit. The CYTB gene of isolates of this species was of the CfII genotype or revealed a unique CfIIa genotype. Phylogenetic analysis of C. siamense isolates from different locations and different crops showed that the resistant isolates were genetically closer to each other than to sensitive isolates, suggesting that field resistance to thiophanate-methyl and azoxystrobin fungicides is derived from a common ancestor.

scholarly journals First Report of Fruit Rot Disease on Pomelo Caused by Lasiodiplodia theobromae in China

Plant Disease ◽  
2011 ◽  
Vol 95 (9) ◽  
pp. 1190-1190 ◽  
Author(s):  
M. Luo ◽  
Z. Y. Dong ◽  
S. Y. Bin ◽  
J. T. Lin
Keyword(s):  
Its Region ◽  
Fruit Rot ◽  
Economic Losses ◽  
Single Spore ◽  
Lasiodiplodia Theobromae ◽  
First Report ◽  
Potted Plants ◽  
Diseased Fruit ◽  
Long Time ◽  
Water Plants

Pomelo (Citrus grandis) is widely cultivated in MeiZhou Guangdong Province of China. In 2008, a disease on pomelo fruit caused significant economic losses by affecting fruit quality. Diseased fruit was collected in December 2008 from MeiZhou Guangdong, surface sterilized in 75% ethanol for 1 min and internal necrotic tissue was transferred to potato dextrose agar (PDA) and incubated at 28°C for 5 days. Three single-spore isolates were obtained from different fruit and identified as Lasiodiplodia theobromae (Pat.) Griffon & Maubl. (synonyms Diplodia natalensis Pole-Evans and Botryodiplodia theobromae Pat.; teleomorph Botryosphaeria rhodina (Cooke) Arx) on the basis of morphological and physiological features. The fungus produced dark brown colonies (initially grayish) on PDA. Young hyphae were hyaline and aseptate, whereas mature hyphae were septate with irregular branches. Cultures of L. theobromae produced globular or irregular pycnidia abundantly on PDA (pH 3.5) at 28°C after 1 month. Mature conidia of L. theobromae were 20 to 26 × 12 to 15.5 μm, subovoid to ellipsoid-ovoid, initially hyaline and nonseptate, remaining hyaline for a long time, and finally becoming dark brown and one septate with melanin deposits on the inner surface of the wall arranged longitudinally giving a striate appearance to the conidia. The internal transcribed spacer (ITS) region of the rDNA was amplified from gDNA using primers ITS1 (5′-TCCGATGGTGAACCTGCGG-3′) and ITS4 (5′-TCCTCCGCTTATTGATATGC-3′) (1). Amplicons were 542 bp long (GenBank Accession No. JF693024) and had 100% nucleotide identity with the corresponding sequence (GenBank Accession No. EU860391) of L. theobromae isolated from a Pinus sp. (2). To satisfy Koch's postulates, six asymptomatic fruit on potted plants were sprayed until runoff with a spore suspension (1 × 106 spores/ml) prepared from 30-day-old cultures of one isolate. Control fruit received water. Plants were covered with sterile wet gauze to maintain high humidity. Fruit spot symptoms similar to those on diseased field fruit appeared after 15 days on all inoculated fruits. L. theobromae was reisolated from all inoculated test fruit. No symptoms were observed on the fruit of control plants. To our knowledge, this is the first report of L. theobromae causing disease on pomelo fruit in China. This pathogen has also been previously reported to be economically important on a number of other hosts by mostly affecting the leaves. References: (1) J. C. Batzer et al. Mycologia 97:1268, 2005. (2) C. A. Pérez et al. Fungal Divers. 41:53,2010.

scholarly journals Identification of Resistance to Multiple Fungicides in Field Populations of Venturia inaequalis

Plant Disease ◽  
2011 ◽  
Vol 95 (8) ◽  
pp. 921-926 ◽  
Author(s):  
Kimberly S. Chapman ◽  
George W. Sundin ◽  
Janna L. Beckerman
Keyword(s):  
Fungicide Resistance ◽  
Mycelial Growth ◽  
Venturia Inaequalis ◽  
Apple Scab ◽  
Field Resistance ◽  
Single Spore ◽  
Mycelium Growth ◽  
Thiophanate Methyl ◽  
Development Of Resistance

Venturia inaequalis, the causal agent of apple scab, is controlled primarily by fungicides. Long-term, extensive fungicide use has led to the development of resistance to multiple fungicides. To assess fungicide resistance, isolates of V. inaequalis were collected from Indiana and Michigan orchards. Single-spore derived isolates were evaluated by mycelium growth assays with previously determined discriminatory doses on media containing dodine, kresoxim-methyl, myclobutanil, or thiophanate-methyl. Of 195 isolates tested, 5.2, 0.7, 57.0, and 92.6% of isolates were found to be resistant to dodine, kresoxim-methyl, myclobutanil, and thiophanate-methyl, respectively. This is the first report of kresoxim-methyl field resistance in these states. Isolates resistant or shifted to a single fungicide were often found to have multiple fungicide resistance. Of all isolates tested, 38% were identified as resistant or shifted to two fungicides, and 12% were resistant or shifted to all four fungicides tested. No fitness penalty was found for isolates resistant to multiple fungicides based on a statistical analysis of mycelial growth and conidial production.

scholarly journals First report of Fusarium incarnatum causing fruit rot of litchi in China

Plant Disease ◽  
2021 ◽  
Author(s):  
Zhaoyin Gao ◽  
Jiaobao Wang ◽  
Zhengke Zhang ◽  
Min Li ◽  
Deqiang Gong ◽  
...  
Keyword(s):  
Southern China ◽  
Fusarium Species ◽  
Morphological Characteristics ◽  
Fruit Rot ◽  
Conidial Suspension ◽  
Single Spore ◽  
Internal Transcribed Spacer Region ◽  
First Report ◽  
Litchi Fruit ◽  
His3 Gene

Litchi (Litchi chinensis Sonn.) is an indigenous tropical and subtropical fruit in Southern China with an attractive appearance, delicious taste, and good nutritional value (Jiang et al. 2003). In March 2020, brown rots were observed on nearly ripe litchi fruits (cv. Guihuaxiang) in an orchard of Lingshui county, Hainan province of China (18.615877° N, 109.948871° E). About 5% fruits were symptomatic in the field, and the disease caused postharvest losses during storage. The initial infected fruits had no obvious symptoms on the outer pericarp surfaces, but appeared irregular, brown to black-brown lesions in the inner pericarps around the pedicels. Then lesions expanded and became brown rots. Small tissues (4 mm × 4 mm) of fruit pericarps were cut from symptomatic fruits, surface-sterilized in 1% sodium hypochlorite for 3 min, rinsed in sterilized water three times, plated on potato dextrose agar (PDA) and incubated at 28℃ in the darkness. Morphologically similar colonies were isolated from 85% of 20 samples after 4 days of incubation. Ten isolates were purified using a single-spore isolation method. The isolates grown on PDA had abundant, fluffy, whitish to yellowish aerial mycelia, and the reverse side of the Petri dish was pale brown. Morphological characteristics of conidia were further determined on carnation leaf-piece agar (CLA) (Leslie et al. 2006). Macroconidia were straight to slightly curved, 3- to 5-septates with a foot-shaped basal cell, tapered at the apex, 2.70 to 4.43 µm × 18.63 to 37.58 µm (3.56 ± 0.36 × 28.68 ± 4.34 µm) (n = 100). Microconidia were fusoid to ovoid, 0- to 1-septate, 2.10 to 3.57 µm × 8.18 to 18.20 µm (2.88 ± 0.34 × 11.71 ± 1.97 µm) (n = 100). Chlamydospores on hyphae singly or in chains were globose, subglobose, or ellipsoidal. Based on cultural features and morphological characteristics, the fungus was identified as a Fusarium species (Leslie et al. 2006). To further confirm the pathogen, DNA was extracted from the 7-day-old aerial mycelia of three isolates (LZ-1, LZ-3, and LZ-5) following Chohan et al. (2019). The sequences of the internal transcribed spacer region of rDNA (ITS), translation elongation factor-1 alpha (tef1) gene, and histone H3 (his3) gene were partially amplified using primers ITS1/ITS4, EF1-728F/EF1-986R, and CYLH3F/CYLH3R, respectively (Funnell-Harris et al. 2017). The nucleotide sequences were deposited in GenBank (ITS: 515 bp, MW029882, 533 bp, MW092186, and 465 bp, MW092187; tef1: 292 bp, MW034437, 262 bp, MW159143, and 292 bp, MW159141; his3: 489 bp, MW034438, 477 bp, MW159142, and 474 bp, MW159140). The ITS, tef1, and his3 genes showed 99-100% similarity with the ITS (MH979697), tef1 (MH979698), and his3 (MH979696) genes, respectively of Fusarium incarnatum (TG0520) from muskmelon fruit. The phylogenetic analysis of the tef1 and his3 gene sequences showed that the three isolates clustered with F. incarnatum. Pathogenicity tests were conducted by spraying conidial suspension (1×106 conidia/ml) on wounded young fruits in the orchid. Negative controls were sprayed with sterilized water. Fruits were bagged with polythene bags for 24 hours and then unbagged for 10 days. Each treatment had 30 fruits. The inoculated fruits developed symptoms similar to those observed in the orchard and showed light brown lesions on the outer pericarp surfaces and irregular, brown to black-brown lesions in the inner pericarps, while the fruits of negative control remained symptomless. The same fungus was successfully recovered from symptomatic fruits, and thus, the test for the Koch’s postulates was completed. F. semitectum (synonym: F. incarnatum) (Saha et al. 2005), F. oxysporum (Bashar et al. 2012), and F. moniliforme (Rashid et al. 2015) have been previously reported as pathogens causing litchi fruit rots in India and Bangladesh. To our knowledge, this is the first report of Fusarium incarnatum causing litchi fruit rot in China.

scholarly journals First Report of Brown Rot Caused by Monilinia fructicola on Nectarine in Serbia

Plant Disease ◽  
2013 ◽  
Vol 97 (1) ◽  
pp. 147-147 ◽  
Author(s):  
J. Hrustić ◽  
M. Mihajlović ◽  
B. Tanović ◽  
G. Delibašić ◽  
I. Stanković ◽  
...  
Keyword(s):  
Prunus Persica ◽  
Its Region ◽  
Fruit Rot ◽  
Economic Losses ◽  
Morphological Identification ◽  
Single Spore ◽  
Daily Growth ◽  
Causal Organism ◽  
First Report ◽  
Apple Fruits

In August 2011, nectarine (Prunus persica (L.) Batsch var. nucipersica (Suckow) C. K. Schneid) fruit originated from Oplenac region with symptoms of fruit rot was collected at a green market in Belgrade. Fruit had large, brown, sunken lesions covered with grayish brown tufts. Symptoms resembled those caused by species of Monilinia including M. laxa, M. fructigena, or M. fructicola (2). In order to isolate the causal organism, small superficial fragments of pericarp were superficially disinfected with commercial bleach and placed on potato dextrose agar (PDA). The majority (32 out of 33) isolates formed rosetted non-sporulating colonies with lobed margins resembling those of M. laxa. However, one isolate (Npgm) produced an abundant, grayish-white colony with even margins and concentric rings of sporogenous mycelium, resembling those described for M. fructicola (2). Conidia were one-celled, hyaline, ellipsoid to lemon shaped, 7.38 to 14.76 × 4.92 to 9.84 μm, and borne in branched monilioid chains. The average daily growth on PDA at 24°C was 10.9 mm. A single-spore isolate of Npgm was identified as M. fructicola based on the morphology of colony and conidia, temperature requirements, and growth rate (2). Morphological identification was confirmed by an amplified product of 535 bp using genomic DNA extracted from the mycelium of pure culture and species-specific PCR for the detection of M. fructicola (2). The ribosomal internal transcribed spacer (ITS) region of rDNA of Npgm was amplified and sequenced using primers ITS1/ITS4. Sequence analysis of ITS region revealed 100% nucleotide identity between the isolate Npgm (GenBank Accession No. JX127303) and 17 isolates of M. fructicola from different parts of the world, including four from Europe (FJ411109, FJ411110, GU967379, JN176564). Pathogenicity of the isolate Npgm was confirmed by inoculating five surface-disinfected mature nectarine and five apple fruits by placing a mycelial plug under the wounded skin of the fruit. Nectarine and apple fruits inoculated with sterile PDA plugs served as a negative controls. After a 3-day incubation at 22°C, inoculated sites developed brown lesions and the pathogen was succesfully reisolated. There were no symptoms on the control nectarine or apple fruits. M. fructicola is commonly present in Asia, North and South America, New Zealand, and Australia, while in the EPPO Region the pathogen is listed as an A2 quarantine organism (3). In Europe, the first discovery of M. fructicola was reported in France and since then, it has been found in Hungary, Switzerland, the Czech Republic, Spain, Slovenia, Italy, Austria, Poland, Romania, Germany, and Slovakia (1). Most recently, M. fructicola was found on stored apple fruits in Serbia (4). To our knowledge, this is the first report of M. fructicola decaying peach fruit in Serbia. These findings suggest that the pathogen is spreading on its principal host plants and causing substantial economic losses in the Serbian fruit production. References: (1) R. Baker et al. European Food Safety Authority. Online publication. www.efsa.europa.eu/efsajournal . EFSA J. 9:2119, 2011. (2) M. J. Côté. Plant Dis. 88:1219, 2004. (3) OEPP/EPPO. EPPO A2 list of pests recommended for regulation as quarantine pests. Version 2009-09. http://www.eppo.org/QUARANTINE/listA2.htm . (4). M. Vasic et al. Plant Dis. 96:456, 2012.

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