scholarly journals First Report of Pulp Rot in the Externally Asymptomatic Pomegranate Fruit Caused by Talaromyces albobiverticillius in Henan Province, China

Plant Disease ◽  
2021 ◽  
Author(s):  
Siliang Huang ◽  
Ting Li ◽  
Tiantian Yang ◽  
Xue Ling Zheng ◽  
Di Yang ◽  
...  
Keyword(s):  
Phylogenetic Trees ◽  
Henan Province ◽  
Fruit Rot ◽  
Gene Sequences ◽  
Tubulin Gene ◽  
First Report ◽  
Rdna Its ◽  
Phenotypic Features ◽  
Pomegranate Fruit ◽  
Β Tubulin

As a popular deciduous fruit tree, pomegranate (Punica granatum L.) is grown from tropical to temperate zones worldwide, therein China has at least 120000 hm2 cultivation area. In August 2020, severe pulp rot occurred in the externally asymptomatic pre-harvest pomegranate fruit on a 3-year-old soft-seeded variety (Tunisia) in the Zhanghe village (32º40´34˝N, 111º44´20˝E) of Jiuchong township, Xichuan county in Henan province, China with 6.4-20 (av. 12.6) % pulp rot incidence evaluated from 11 freshly sampled fruits (360 pulps per fruit investigated). The fruits showed no external symptoms, however, browning occurred on part of their pulps before harvest compared to the normal ones with white or pink color. The surface of the externally asymptomatic fruits was sterilized with 75% ethanol, and air-dried in a clean bench. The surface-disinfected fruits were dissected with a sterilized knife. Brown pulps from the fruits were picked up using flame-sterilized tweezers and placed on potato dextrose agar (PDA) plates. After five days of incubation at 28 °C, pure fungal cultures with similar phenotypic features developed from the affected pulps. Two randomly selected isolates Tp-2 and Tp-8 were used for the study. The colony surface of the isolates was greyish-green with claret-red exudates. Claret-red pigments were commonly secreted into the medium from the colonies. Conidia were unicellular, hyaline to greyish, mostly rugby ball-shaped with a dimension of 2.2-3.5 (2.7) µm × 1.6-2.0 (1.8) µm (n=50) for Tp-2, and 2.2-3.1 (2.6) µm × 1.6-2.2 (1.8) µm (n=50) for Tp-8. The rDNA internal transcribed spacer (ITS) and β-tubulin gene sequences of the isolates were amplified with primers ITS1/ITS4 and Bt2a/Bt2b, respectively. Sequences were submitted to GenBank with accession numbers MW132153 and MW132077 for the rDNA-ITS sequences, and MW507822 and MW507823 for the β-tubulin gene sequences of Tp-2 and Tp-8, respectively, with a maximal sequence identity greater than 99 % to multiple strains of Talaromyces albobiverticillius (TA) based on BLAST analyses. In the Neighbor-joining phylogenetic trees constructed using rDNA-ITS and β-tubulin gene sequences, both Tp-2 and Tp-8 formed a clade with mutiple strains of TA, clearly separated from other Talaromyces spp. Conidial suspensions (106 spores ml-1) of Tp-2 and Tp-8 were separately injected into five pomegranate fruits (Tunisia) sampled from an orchard free of the disease with a sterilized syringe. Five fruits inoculated with sterilized water were used as control (CK). The inoculated fruits were incubated at 25 °C for 10 days and cut out through the inoculated sites. Pulp rot symptoms occurred in the Tp-2/Tp-8-inoculated fruits, being similar to the naturally affected pulps. The CK pulps remained symptomless during the inoculation tests. Fungal cultures with the same phenotypic features as the inocula were constantly isolated from the brown pulps of the inoculated fruits, verifying both Tp-2 and Tp-8 as the causal agents of the disease based on Koch’s postulates. During a long-term (30-40 days) storage at ambient conditions, fruits sampled from affected orchards developed brown lesions on their peels from which TA cultures could be isolated. TA was reported as the pathogen causing postharvest fruit rot on pomegranate in Italy (Mincuzzi et al. 2017). This is the first report of TA causing pulp rot in the externally asymptomatic pomegranate fruit in China.

scholarly journals First Report of Soft Rot Caused by Aspergillus niger sensu lato on Mother-in-law’s Tongue in China

Plant Disease ◽  
2020 ◽  
Author(s):  
Siliang Huang ◽  
Xue Ling Zheng ◽  
Di Yang ◽  
Jinping An ◽  
Lu Wang ◽  
...  
Keyword(s):  
Aspergillus Niger ◽  
Phylogenetic Tree ◽  
Soft Rot ◽  
Leaf Margin ◽  
Strict Sense ◽  
Tubulin Gene ◽  
First Report ◽  
Rdna Its ◽  
Pathogenicity Tests ◽  
Β Tubulin

“Mother-in-law’s tongue” (MLT) [Dracaena trifasciata (Prain) Mabb. (syn. Sansevieria trifasciata Prain.)], also known as “Saint George's sword", “snake plant”, “tiger's tail orchid", etc., is an evergreen perennial ornamental plant grown worldwide. In September 2016, severe soft rot occurred on the leaves of MLT in a flower market in Nanyang city (32º56´N, 112º32´E), Henan province, China with 25% disease incidence (n=100). Water-soaked spots initially appeared on the leaf margin, enlarged rapidly, and became soft rot under excessively watered conditions. A blight zone was visualized at the margin of a developing lesion in backlit conditions. Severely affected leaves folded down from the lesions. Lesion expansion stopped under dry conditions. Grey or dark brown mycelia were frequently seen on the lesions. Tissue pieces (4×4 mm2) at the margin of lesions were cut out, treated with 75% ethanol for 10 s, followed by 70 s in 0.1% HgCl2, rinsed eight times with sterile water, and plated on potato dextrose agar (PDA) medium. Pure Aspergillus cultures were obtained from the surface-disinfected lesions after 4 days of incubation at 26°C. Two single-spore-derived isolates (An-1 and An-2) were randomly selected and used for morphological and molecular identifications as well as pathogenicity tests. The isolates formed round dark brown colonies with a large number of conidia after 5 days of incubation on PDA at 28°C. Conidia were subsphaeroidal or oblate, unicellular, dark brown, 2.9-4.2(3.5) × 1.9-3.4(2.7) μm in size (n=100), developed from a two-series of strigmata born on a conidial head, with ridge or stab-shaped prominences. For pathogenicity tests, the two isolates were separately grown on oatmeal agar and incubated at 30°C for 6 days. Mycelial plugs (5 mm diam.) were inoculated on the scalpel incision X-shaped wounds of surface-disinfected leaves of MLT. The inoculated leaves were kept on a two-layer of wet napkin in a steel basin covered with a plastic film. Soft rot symptoms developed from the wounds 6 days after incubation, similar to those observed on naturally affected leaves. The An-1- and An-2-inoculated unwounded leaves remained symptomless during the pathogenicity tests. Fungal cultures with the same phenotypes as the inocula were consistently reisolated from the lesions of the leaves inoculated by each of the two isolates, verifying the isolates as the causal agent of the disease based on Koch’s postulates. Both β-tubulin gene and rDNA-ITS (internal transcribed spacer) sequences of the two isolates were separately amplified and sequenced. Sequences were submitted to GenBank with accession numbers MN259522 and MN259523 for the β-tubulin gene sequences, and accession numbers MN227322 and MN227324 for the rDNA-ITS sequences of An-1 and An-2, respectively. Both An-1 and An-2 were clustered with members of Aspergillus niger van Tieghem in the phylogenetic tree of rDNA-ITS, clearly separated from other Aspergillus spp. In the phylogenetic tree of β-tublin gene, both An-1 and An-2 formed a subclade inside a large clade consisting of members of A. niger in strict sense. Based on the molecular and morphological results, both An-1 and An-2 clearly separated from other Aspergillus spp. and can be considered as A. niger sensu lato. Foliar diseases of MLT are known to be caused by a few fungal species such as Chaetomella spp. (Li et al. 2014) and Colletotrichum sansevieriae (Nakamura et al. 2006). This is the first report of A. niger sensu lato causing soft rot on MLT in China.

scholarly journals First Report of Gliocephalotrichum bulbilium and G. simplex Causing Fruit Rot of Rambutan in Puerto Rico

Plant Disease ◽  
2012 ◽  
Vol 96 (8) ◽  
pp. 1225-1225 ◽  
Author(s):  
L. M. Serrato-Diaz ◽  
E. I. Latoni-Brailowsky ◽  
L. I. Rivera-Vargas ◽  
R. Goenaga ◽  
R. D. French-Monar
Keyword(s):  
Puerto Rico ◽  
Sri Lanka ◽  
Mycelial Growth ◽  
Fruit Rot ◽  
Its2 Region ◽  
Research Station ◽  
Diseased Plant ◽  
Tubulin Gene ◽  
First Report ◽  
Β Tubulin

Post-harvest disease losses of rambutan (Nephelium lappaceum L.) have been reported worldwide and several pathogens have been associated with fruit rot (3,4). In 2011, fruit rot of rambutan was observed on 11-year-old trees at the USDA-ARS Tropical Agriculture Research Station in Mayaguez, Puerto Rico. Infected fruit sections (1 mm2) were surface-sterilized, rinsed with sterile deionized-distilled water, and transferred to acidified potato dextrose agar (APDA). Gliocephalotrichum bulbilium J.J. Ellis & Hesseltine (Gb) and G. simplex (J.A. Meyer) B. Wiley & E. Simmons (Gs) were identified using a taxonomic key (1). In corn meal agar (CMA), five isolates of Gb were light yellow-to-light brown. Conidiophores had sterile stipe extensions ranging from 120 to 150 μm long and were produced contiguous to the erect conidiogenous penicilli. Conidia were unicellular, smooth, oblong to elliptical, and 5.5 to 7.5 μm long by 2.0 to 2.5 μm wide. Bulbilloid aggregates were observed and averaged 70 μm long. In CMA, five isolates of Gs were light brown-to-chestnut brown. Conidiophores had sterile stipe extensions 130 to 180 μm long that were produced approximately 15 to 30 μm away from the conidiogenous penicilli. Conidia were unicellular, smooth, cylindrical to elliptical, and with slightly curved ends ranging from 6.5 to 8.5 μm long by 2.0 to 2.5 μm wide. Chlamydospores were unicellular, brown, smooth and thick-walled, averaging 35 μm long. Pathogenicity tests were conducted on five detached fruits per isolate. Five isolates of each Gliocephalotrichum spp. were inoculated on fruits using 5-mm mycelial disks of 8-day-old pure cultures grown in APDA. Untreated controls were inoculated with APDA disks only. Inoculated fruit was kept in a humid chamber for 8 days at 25°C under 12 hours of fluorescent light. Test was repeated once. Five days after inoculation (DAI), white mycelial growth for Gb and golden mycelial growth for Gs were observed on rambutan fruits. Eight DAI, fruit rot, and aril (flesh) rot symptoms were observed on fruits inoculated with isolates of Gb and Gs. Infected fruit changed in color from red to brown, and, on average, mycelia of Gb and Gs covered 50 and 60% of the fruit, respectively. Conidiophores were observed on spintems (hair-like appendages). Control fruit did not rot. Both species were reisolated from diseased plant tissue, thus fulfilling Koch's postulates. For molecular identification of these species of Gliocephalotrichum, the ITS1-5.8S-ITS2 region of the rDNA and a fragment of the β-tubulin gene were amplified by PCR and aligned with other Gb and Gs sequences in NCBI GenBank for comparison. The sequences submitted to GenBank included Gs Accession Nos. JQ688045 and JQ688046 and Gb Accession Nos. JQ688044 and JQ68847 for the ITS sequences. For the β-tubulin gene, Gs Accession Nos. JQ688049 and JQ688050 and Gb Accession Nos. JQ688048 and JQ688051. Both DNA regions had 99.9 to 100% sequence identity to other isolates of Gb and Gs reported in GenBank (1). Gliocephalotrichum spp. have been associated with rambutan fruit rot in Hawaii, Sri Lanka and Thailand (2,4). To our knowledge, this is the first report of G. bulbilium and G. simplex causing fruit rot of rambutan in Puerto Rico. References: (1) C. Decock et al. Mycologia 98:488, 2006. (2) K. A. Nishijima and P. A. Follett. Plant Dis. 86:71, 2002. (3) L. M. Serrato et al. Phytopathology 100:S176, 2010. (4) D. Sivakumar et al. J. Natn. Sci. Coun. Sri Lanka 25:225, 1997.

scholarly journals First Report of Leaf Spot on White Chrysanthemum (Chrysanthemum morifolium) Caused by Epicoccum sorghinum in Hubei province, China

Plant Disease ◽  
2020 ◽  
Author(s):  
Dahui Liu ◽  
Qiaohuan Chen ◽  
Yuhuan Miao ◽  
Jinxin Li ◽  
Qi Yang
Keyword(s):  
Leaf Spot ◽  
Hubei Province ◽  
Chrysanthemum Morifolium ◽  
Yield Reduction ◽  
Leaf Spot Disease ◽  
Molecular Characteristics ◽  
Gene Sequences ◽  
First Report ◽  
Spot Disease ◽  
Rdna Its

White Chrysanthemum (Chrysanthemum morifolium), a perennial herb of the Compositae family, is used for traditional medicine. The planting area of white chrysanthemum in Macheng city, Hubei Province is about 3333 ha and the annual output can reach more than 5000 tons. In 2019, leaf spot disease appeared on almost all middle and lower leaves of white chrysanthemum in most fields of Fengshumiao county, Macheng city (N31°29′57″, E115°05′49″). This county has 33 acres white chrysanthemum planting area, and most of the plants in the county were infected with the leaf spot disease. The average incidence of leaf spot disease was 65%, and incidence in some areas was 100%. In our observations, leaf spot disease can occur throughout the whole growth period of white chrysanthemum, and it will become more serious under the high temperature and humidity condition. Usually, the diseased leaves account for 30 to 80% of the total leaves on the plant. Leaf spot initially manifests as necrotic lesions on the edge and tip of the leaf, and then the lesions coalesce and gradually expand to form irregular light-brown to brown-black spots, eventually leading to necrosis and curling of the entire leaf. This disease seriously affects the growth and development of plants, resulting in the decline of yield and quality of white chrysanthemum. Ten symptomatic leaf samples were collected, the surfaces were disinfected with 0.1% mercuric chloride (HgCl2) for 3 min, and washed with sterile distilled water three times. Ten tissue samples at the junction of diseased and healthy areas (0.5 × 0.5 cm2) were cut and placed on potato dextrose agar (PDA) medium containing 100 µg/ml cefotaxime sodium and incubated in a dark chamber at 28°C. After 2 days, the hyphal tips from the edges of growing colonies were transferred to fresh PDA plates for further purification. Finally, eight isolates were obtained and these isolates were similar in morphology. The color of purified isolates was initially white to pale yellow. After six days of incubation, colonies had a diameter of 8 cm and the cultures were pale gray and starting to secrete scarlet pigment. After 15 days incubation, the colonies were grayish brown, while the backside was reddish-brown. Gray to tan chlamydospores were observed, nearly spherical, with a wart-like surface. Unicellular chlamydospores were 7.91 to 32.23 × 12.03 to 38.42 µm (n=30) and multicellular chlamydospores were 6.32 to 25.10 × 21.75 to 100.05 µm (n=30). The morphological characteristics were similar to Epicoccum sorghinum (Kang et al. 2019). The isolate FDY-5 was chosen for molecular identification. The sequence of rDNA-ITS, TUB, and LSU of the FDY-5 were amplified (GenBank MT800929, MT799852, and MT800935, respectively) (White et al. 1990; Carbone and Kohn 1999; Lumbsch et al. 2000). BLAST results showed that the rDNA-ITS sequences, the TUB gene sequences, and LSU gene sequences of strain FDY-5 shared 99% identity with the sequences of E. sorghinum (syn. Phoma sorghina) in GenBank (MN555348.1, MF987525.1, MK516207.1, respectively). Moreover, a phylogenetic tree of the LSU gene sequence of FDY-5 was constructed based on the Neighbor-Joining (NJ) method in MEGA6 software (Tamura et al. 2013) and revealed that strain FDY-5 was closest to E. sorghinum. Based on morphological and molecular characteristics, the fungus was identified as E. sorghinum. Pathogenicity tests were conducted on two-month-old white chrysanthemum plants. The upper three leaves of three plants were randomly selected for stab treatment and were inoculated with 5 × 5 mm mycelial discs produced from a fifteen-day-old colony on PDA. The inoculated and control (treated with sterile PDA disks) plants were incubated in a moist chamber (25 ± 2 °C, RH 85%). The first lesions appeared 1 day after inoculation on leaves, and the necrotic lesion area expanded outward and showed typical symptoms 3 days later. To fulfill Koch's postulates, the pathogen was reisolated from nine inoculated leaves by repeating the above isolating operation, and confirmed as E. sorghinum by morphology. To the best of our knowledge, this is the first report of E. sorghinum causing leaf spot on white chrysanthemum in China. E. sorghinum has a wide host range worldwide and often causes crop yield reduction. This report will facilitate the diagnosis of white chrysanthemum leaf spot of white chrysanthemum allowing control measures to be adopted to manage this disease in a timely manner. References Carbone, I., and Kohn, L. M. 1999. Mycologia 91:553. Kang, Y., et al. 2019. Plant Dis. 103 (7):1787. Lumbsch, H., et al. 2000. Plant Biol. 2:525. Tamura, K., et al. 2013. Mol. Biol. Evol. 30:2725-2729. White, T. J., et al. 1990. Page 315 in:PCR protocols:a guide to methods and applications. Academic Press, San Diego, CA. Funding Funding was supported by Major Increase and Decrease Projects at the Central Level of China (2060302) and the National Key Research and Development Program (2017FYC1700704).

scholarly journals First Report of Pomegranate Fruit Rot Caused by Botryosphaeria dothidea in Anhui Province of China

Plant Disease ◽  
2020 ◽  
Vol 104 (10) ◽  
pp. 2736-2736
Author(s):  
Chun-Yan Gu ◽  
Xue Yang ◽  
Mohamed N. Al-Attala ◽  
Muhammad Abid ◽  
Seinn Sandar May Phyo ◽  
...  
Keyword(s):  
Anhui Province ◽  
Fruit Rot ◽  
Botryosphaeria Dothidea ◽  
First Report ◽  
Pomegranate Fruit

scholarly journals First Report of Lasiodiplodia theobromae Causing Inflorescence Blight and Fruit Rot of Longan (Dimocarpus longan L.) in Puerto Rico

Plant Disease ◽  
2014 ◽  
Vol 98 (2) ◽  
pp. 279-279 ◽  
Author(s):  
L. M. Serrato-Diaz ◽  
L. I. Rivera-Vargas ◽  
R. Goenaga ◽  
R. D. French-Monar
Keyword(s):  
Puerto Rico ◽  
Fruit Rot ◽  
Fluorescent Light ◽  
Its2 Region ◽  
Tropical Fruit ◽  
Lasiodiplodia Theobromae ◽  
First Report ◽  
Wide Range ◽  
Dimocarpus Longan ◽  
Β Tubulin

Dimocarpus longan L., commonly known as longan, is a tropical fruit tree of the Sapindaceae family. From 2008 to 2010, a disease survey for longan was conducted in March and October in Puerto Rico. Fruit rot and inflorescence blight (rotting of the rachis, rachilla, and flowers) were observed in fields of longan at the USDA-ARS Research Farm in Isabela, and two commercial orchards in Puerto Rico. Tissue sections (1 mm2) of diseased inflorescences and surface of the fruit were disinfested with 70% ethanol, rinsed with sterile water, and transferred to acidified potato dextrose agar (APDA). Three isolates of Lasiodiplodia theobromae (Pat.) Griffon & Maubl. (Lt) were isolated from symptomatic tissue and identified morpho-molecularly using a taxonomic key for the Botryosphaeriaceae and DNA sequence analysis (1). In APDA, colonies of Lt had initial greenish-gray aerial mycelia that turned dark brown with age. Pycnidia were dark brown to black. Immature conidia were sub-ovoid to ellipsoid, apex rounded, truncate at the base, thick-walled, hyaline, and one-celled, becoming dark brown, two-celled, and with irregular longitudinal striations when mature. Conidia (n = 50) for all the isolates averaged 26.9 μm long by 13 μm wide. For molecular identification, the ITS1-5.8S-ITS2 region and fragments of the β-tubulin and elongation factor 1-alpha (EF1-α) genes were sequenced and BLASTn searches done in GenBank. Accession numbers of gene sequences of Lt submitted to GenBank were KC964546, KC964547, and KC964548 for ITS region; KC964549, KC964550, and KC964551 for β-tubulin; and KC964552, KC964553, and KC964554 for EF1-α. For all genes used, sequences were 99 to 100% identical to reference isolate CBS164.96 of Lt reported in GenBank (accessions AY640255, EU673110, and AY640258). Pathogenicity tests were conducted on six random healthy non-detached inflorescences of longan and six healthy detached fruits per isolate. Unwounded inflorescences and fruit were inoculated with 5-mm mycelial disks from 8-day-old pure cultures grown in APDA. Inflorescences were enclosed in plastic bags for 5 days under field conditions while fruits were kept in a humid chamber using plastic boxes for 5 days under laboratory conditions of 25°C and 12 h of fluorescent light. Untreated controls were inoculated with APDA disks only. The experiment was repeated once. Five days after inoculation, isolates of Lt caused inflorescence blight, fruit rot, and aril (flesh) rot. Inflorescences turned brown and flower mummification was observed on the inflorescences. The exocarp (peel) and endocarp (aril) turned dark brown and mycelial growth and pycnidia of Lt were observed on fruits. Untreated controls did not show any symptoms and no fungi were re-isolated from tissue. In diseased inflorescences and fruits, Lt was re-isolated from diseased tissue and identified using morphological and molecular parameters, thus fulfilling Koch's postulates. Lt has been reported to cause dieback, stem end rot, and fruit rot on a wide range of plants host (2,4). In longan, Lt has been reported causing fruit rot in Thailand (3). To our knowledge, this is the first time that Lt has been reported causing inflorescence blight in longan and the first report of Lt causing fruit rot in Puerto Rico. References: (1) A. J. L. Phillips. Key to the various lineages in “Botryosphaeria” Version 01 2007. Retrieved from http://www.crem.fct.unl.pt/botryosphaeria_site/key.htm , 26 November 2013. (2) B. Slippers et al. Mycologia 97:99, 2005. (3) P. Suwanakood et al. Asian J. Biol. Ed. 3:47, 2007. (4) A. F. Wright and P. F. Harmon. Plant Dis. 93:962, 2009.

Benzimidazole and diphenylamine sensitivity and identity of Penicillium spp. that cause postharvest blue mold of apples using β-tubulin gene sequences

2005 ◽  
Vol 36 (1) ◽  
pp. 41-49 ◽  
Author(s):  
P.L. Sholberg ◽  
C. Harlton ◽  
P. Haag ◽  
C.A. Lévesque ◽  
D. O’Gorman ◽  
...  
Keyword(s):  
Gene Sequences ◽  
Blue Mold ◽  
Tubulin Gene ◽  
Penicillium Spp ◽  
Β Tubulin

scholarly journals First Report of a Soft Rot of Philodendron ‘Con-go’ in China Caused by Dickeya dieffenbachiae

Plant Disease ◽  
2012 ◽  
Vol 96 (3) ◽  
pp. 452-452 ◽  
Author(s):  
B. R. Lin ◽  
H. F. Shen ◽  
J. N. Zhou ◽  
X. M. Pu ◽  
Z. N. Chen ◽  
...  
Keyword(s):  
16S Rdna ◽  
Phylogenetic Trees ◽  
Soft Rot ◽  
Gyrb Gene ◽  
Control Treatment ◽  
Gene Sequences ◽  
16S Rdna Gene ◽  
First Report ◽  
Rdna Gene ◽  
Plastic Bags

Philodendron is a popular foliage plant cultivated in interiorscapes of homes, offices, and malls throughout China. A severe outbreak of a soft rot of Philodendron ‘Con-go’ occurred in Guangzhou, China from 2010 to 2011. The disease was characterized by leaf infections starting as pinpoint spots that are water soaked and yellow to pale brown. The lesions are sometimes surrounded by a diffuse yellow halo. When the humidity is high and temperatures are warm to hot, the spots expand rapidly, becoming slimy, irregular, and sunken with light tan centers, darker brown borders, and diffused yellow margins and may involve the entire leaf in a few days. An invasion of the midrib and larger veins by the causal bacterium often results in advancement into the petiole and stem. A survey of three areas of production of Philodendron ‘Con-go’ (5 ha) in Guangzhou revealed that 91% of the fields were affected at an incidence ranging from 15 to 30%. Of 41 bacterial isolates obtained from lesions, three were selected randomly for further characterization. All strains were gram negative, negative for oxidase and positive for catalase and tryptophanase (indole production), and utilized citrate, tartrate, malonate, glucose, sucrose, fructose, and maltose but not glucopyranoside, trehalose, or palatinose. Biolog analysis (version 4.20.05, Hayward, CA) identified the isolates as Pectobacterium chrysanthemi (SIM 0.804 to 0.914). According to Samson et al. (1), it was renamed as a Dickeya sp. PCR was performed on the 16S rDNA gene with primers 27f and 1495r (3) and 1,423 bp of the 16S rDNA gene (GenBank No. JN709491) showed 99% identity to P. chrysanthemi (GenBank No. AF373202), and 98% to Dickeya dieffenbachiae (GenBank No. JF311644). Additionally, the gyrB gene was amplified with primers gyrB-f1 (5′-atgtcgaattcttatgactcctc-3′) and gyrB-r1 (5′-tcaratatcratattcgcygctttc-3′) designed based on all the submitted gyrB gene sequences of Dickeya spp. The dnaX gene was amplified with primers dnaXf and dnaXr (2). The products were sequenced and phylogeny analyses were performed by means of MEGA 5.05. Results showed that the gyrB and the dnaX genes of the strains were 98% homologous to those of D. dieffenbachiae (GenBank Nos. JF311652 and GQ904757). Therefore, on the basis of phylogenetic trees of the 16S rDNA, gyrB, and dnaX gene sequences, the bacterial isolate named PC1 is related to D. dieffenbachiae (100% bootstrap values). Pathogenicity of each of the three strains on Philodendron ‘Con-go’ was confirmed by injecting 60 50-day-old seedlings each with 0.1 ml of the isolate suspension (108 CFU/ml) into the leaves. Another 60 were injected with sterile water to serve as the control treatment. Plants were enclosed in plastic bags and returned to the greenhouse under 50% shade at 32°C day and 28°C night temperatures with high humidity. After 72 h, all the injected plants started to show symptoms similar to those observed on field plants, but no symptoms appeared on the control plants. The reisolates were identical to the inoculated strains in biochemical characteristics. Bacteria characteristic of the inoculated strains were not reisolated from the control plants. To our knowledge, this is the first report of D. dieffenbachiae causing soft rot of Philodendron ‘Con-go' in China. References: (1) R. Samson et al. Evol. Microbiol. 55:1415, 2005. (2) M. Sławiak et al. Eur. J. Plant Pathol. 125:245, 2009. (3) W. G. Weisbury et al. J. Bacteriol. 173:697, 1991.

First report of Coniella granati causing pomegranate fruit rot in Israel

2011 ◽  
Vol 39 (4) ◽  
pp. 403-405 ◽  
Author(s):  
Edna Levy ◽  
Genya Elkind ◽  
Ruth Ben-Arie ◽  
I. S. Ben-Ze’ev
Keyword(s):  
Fruit Rot ◽  
First Report ◽  
Pomegranate Fruit

scholarly journals First Report of Fusarium Maize Ear Rot Caused by Fusarium kyushuense in China

Plant Disease ◽  
2014 ◽  
Vol 98 (2) ◽  
pp. 279-279 ◽  
Author(s):  
J.-H. Wang ◽  
H.-P. Li ◽  
J.-B. Zhang ◽  
B.-T. Wang ◽  
Y.-C. Liao
Keyword(s):  
Fusarium Species ◽  
Morphological Characteristics ◽  
Distilled Water ◽  
Ear Rot ◽  
Tubulin Gene ◽  
Average Growth ◽  
First Report ◽  
Maize Ear Rot ◽  
Maize Ear ◽  
Β Tubulin

From September 2009 to October 2012, surveys to determine population structure of Fusarium species on maize were conducted in 22 provinces in China, where the disease incidence ranged from 5 to 20% in individual fields. Maize ears with clear symptoms of Fusarium ear rot (with a white to pink- or salmon-colored mold at the ear tip) were collected from fields. Symptomatic kernels were surface-sterilized (1 min in 0.1% HgCl2, and 30 s in 70% ethanol, followed by three rinses with sterile distilled water), dried, and placed on PDA. After incubation for 3 to 5 days at 28°C in the dark, fungal colonies displaying morphological characteristics of Fusarium spp. (2) were purified by transferring single spores and identified to species level by morphological characteristics (2), and DNA sequence analysis of translation elongation factor-1α (TEF) and β-tubulin genes. A large number of Fusarium species (mainly F. graminearum species complex, F. verticillioides, and F. proliferatum) were identified. These Fusarium species are the main causal agents of maize ear rot (2). Morphological characteristics of six strains from Anhui, Hubei, and Yunnan provinces were found to be identical to those of F. kyushuense (1), which was mixed with other Fusarium species in the natural infection in the field. Colonies grew fast on PDA with reddish-white and floccose mycelia. The average growth rate was 7 to 9 mm per day at 25°C in the dark. Reverse pigmentation was deep red. Microconidia were obovate, ellipsoidal to clavate, and 5.4 to 13.6 (average 8.8) μm in length. Macroconidia were straight or slightly curved, 3- to 5-septate, with a curved and acute apical cell, and 26.0 to 50.3 (average 38.7) μm in length. No chlamydospores were observed. Identity of the fungus was further investigated by sequence comparison of the partial TEF gene (primers EF1/2) and β-tubulin gene (primers T1/22) of one isolate (3). BLASTn analysis of the TEF amplicon (KC964133) and β-tubulin gene (KC964152) obtained with cognate sequences available in GenBank database revealed 99.3 and 99.8% sequence identity, respectively, to F. kyushuense. Pathogenicity tests were conducted twice by injecting 2 ml of a prepared spore suspension (5 × 105 spores/ml) into maize ears (10 per isolate of cv. Zhengdan958) through silk channel 4 days post-silk emergence under field conditions in Wuhan, China. Control plants were inoculated with sterile distilled water. The ears were harvested and evaluated 30 days post-inoculation. Reddish-white mold was observed on inoculated ears and the infected kernels were brown. No symptoms were observed on water controls. Koch's postulates were fulfilled by re-isolating the pathogen from infected kernels. F. kyushuense, first described on wheat in Japan (1), has also been isolated from rice seeds in China (4). It was reported to produce both Type A and Type B trichothecene mycotoxins (1), which cause toxicosis in animals. To our knowledge, this is the first report of F. kyushuense causing maize ear rot in China and this disease could represent a serious risk of yield losses and mycotoxin contamination in maize and other crops. The disease must be considered in existing disease management practices. References: (1) T. Aoki and K. O'Donnell. Mycoscience 39:1, 1998. (2) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual. Blackwell Publishing, Ames, IA, 2006. (3) F. Van Hove et al. Mycologia 103:570, 2011. (4) Z. H. Zhao and G. Z. Lu. Mycotaxon 102:119, 2007.

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