Displaying publications 81 - 100 of 255 in total

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  1. Keith LM, Matsumoto TK
    Plant Dis, 2013 Jan;97(1):146.
    PMID: 30722309 DOI: 10.1094/PDIS-07-12-0702-PDN
    Mangosteen (Garcinia mangostana L.) is a tropical evergreen tree that produces one of the most prized tropical fruits, commonly known as the "Queen of the Fruits.″ Mangosteen has the potential to occupy a rapidly expanding niche market in Hawaii. In October 2009, a disease was observed that produced brown leaf spots and blotches surrounded by bright yellow halos at a mangosteen orchard located in Hakalau, Hawaii (19° 53' 49″ N, 155° 7' 35″ W). Recently transplanted 10+ year old trees were 95 to 100% infected. Pieces of infected leaves and stems were surface-sterilized, plated on potato dextrose agar (PDA), and incubated at 24°C ± 1°C for 21 days. The fungus growing on PDA was pale buff with sparse aerial mycelium and acervuli containing black, slimy spore masses. Single spore isolates were used for the morphological characteristics and molecular analysis. Conidia were 5-celled. Apical and basal cells were hyaline; the three median cells were umber to olivaceous. Conidia (n = 50) were 24.3 ± 0.2 × 7.5 ± 0.1 μm, with apical appendages, typically three, averaging 24.3 ± 0.4 μm long, and a basal appendage averaging 6.7 ± 0.2 μm long. DNA sequences were obtained from the β-tubulin gene and the internal transcribed spacer (ITS1 and ITS2) and 5.8S regions of the rDNA to confirm the identification. The morphological descriptions and measurements were similar to P. virgatula (Kleb.) Steyaert (1). Although sequence data of the ITS region (GenBank Accession No. JN542546) supports the identity of the fungus as P. virgatula, the taxonomy of this genus remains confused since there are only a few type cultures, so it is impossible to use sequences in GenBank to reliably clarify species names (2). To confirm pathogenicity, six leaves of two 3-year-old seedlings were inoculated. Seven-day-old cultures grown on 10% V8 agar at 24°C under continuous fluorescent lighting were used for inoculations. The inoculum consisted of spore suspensions in sterile distilled water adjusted to 6 × 105 conidia/ml. Using a fine haired paint brush, the inoculum was brushed onto the youngest leaves, while sterile distilled water was used as the control. The plants were incubated in a clear plastic bag placed on the laboratory bench at 24°C for 48 hours, then placed on a greenhouse bench and observed weekly for symptoms. After 14 days, leaf spots ranging in size from pinpoint to 5.4 mm in diameter with a distinctive yellow halo were present. Within 35 days, the leaf spots enlarged to leaf blotches ranging in size from 11.5 × 13.3 mm up to 28.3 × 34.6 mm with brown centers and a distinctive yellow halo identical to the field symptoms. A Pestalotiopsis sp. identical to that used to inoculate the seedlings was recovered from the leaf spots and blotches, confirming Koch's postulates. The experiment was repeated twice. Pestalotiopsis leaf blight has been reported in other countries growing mangosteen, including Thailand, Malaysia, and North Queensland, Australia (3). However, to our knowledge, this is the first report of a Pestalotiopsis sp. causing a disease on mangosteen in Hawaii. Although this disease is considered a minor problem in the literature (3), effective management practices should be established to avoid potential production losses. References: (1) E. F. Guba. Monograph of Pestalotia and Monochaetia. Harvard University Press, Cambridge, MA. 1961. (2) S. S. N. Maharachchikumbura et al. Fungal Div. 50:167, 2011. (3) R. C. Ploetz. Diseases of Tropical Fruit Crops. CABI Publishing. Wallingford, Oxfordshire, UK, 2003.
    Matched MeSH terms: Agar
  2. Nasehi A, Kadir JB, Esfahani MN, Mahmodi F, Ghadirian H, Ashtiani FA, et al.
    Plant Dis, 2013 May;97(5):689.
    PMID: 30722190 DOI: 10.1094/PDIS-10-12-0902-PDN
    In June 2011, lettuce (Lactuca sativa) plants cultivated in major lettuce growing areas in Malaysia, including the Pahang and Johor states, had extensive leaf spots. In severe cases, disease incidence was recorded more than 80%. Symptoms on 50 observed plants initially were as water soaked spots (1 to 2 mm in diameter) on leaves, and then became circular spots spreading over much of the leaves. In this research, main lettuce growing areas infected by the pathogen in the mentioned states were investigated and the pathogen was isolated onto potato dextrose agar (PDA). Colonies observed were greyish green to light brown. Single conidia were formed at the terminal end of conidiophores that were 28.8 to 40.8 μm long and 11.0 to 19.2 μm wide, and 2 to 7 transverse and 1 to 4 longitudinal septa. To produce conidia, the fungus was grown on potato carrot agar (PCA) and V8 juice agar media under 8-h/16-h light/dark photoperiod. Fourteen isolates were identified Stemphylium solani based on morphological criteria described by Kim et al. (1). To confirm morphological characterization, DNA of the fungus was extracted from mycelium and PCR was done using universal primers ITS5 (5'-GGAAGTAAAAGTCGTAACAAGG-3') and ITS4 (5'-TCCTCCGCTTATTGATATGC-3'), which amplified the internal transcribed spacer (ITS) region of rDNA (2). The sequencing result was subjected to BLAST analysis which was 99% identical to the other published sequences in the GenBank database (GenBank Accession Nos. AF203451 and HQ840713). The nucleotide sequence was deposited in GenBank under Accession No. JQ736022. Pathogenicity testing of representative isolate was done using 20 μl of conidial suspension with a concentration of 1 × 105/ml in droplets (three drops on each leaf) on four detached 45-day-old lettuce leaves cv. BBS012 (3). Fully expended leaves were placed on moist filter paper in petri dishes and were incubated in humid chambers at 25°C. The leaves inoculated with sterile water served as control. After 7 days, disease symptoms were observed, which were similar to those symptoms collected in infected fields and the fungus was reisolated and confirmed as S. solani based on morphological criteria (1) and molecular characterization (2). Control leaves remained healthy. Pathogenicity testing was completed twice. To our knowledge, this is the first report of S. solani on lettuce in Malaysia and it may become a serious problem because of its broad host range, variability in pathogenic isolates, and prolonged active phase of the disease cycle. Previous research has shown that S. solani is a causal agent of gray leaf spot on lettuce in China (4). References: (1) B. S. Kim et al. Plant Pathol. J. 20:85, 2004. (2) Y. R. Mehta et al. Current Microbiol. 44:323, 2002. (3) B. M. Pryor and T. J. Michailides. Phytopathology 92:406, 2002. (4) F. L. Tai. Sylloge Fungorum Sinicorum, Sci. Press, Acad. Sin., Peking, 1979.
    Matched MeSH terms: Agar
  3. Mahmodi F, Kadir JB, Wong MY, Nasehi A, Soleimani N, Puteh A
    Plant Dis, 2013 May;97(5):687.
    PMID: 30722185 DOI: 10.1094/PDIS-09-12-0843-PDN
    Bok choy (Brassica chinensis L.) is a temperate vegetable grown in the cool highland areas of Malaysia. In June 2010, vegetable growing areas of the Cameron Highlands, located in Pahang State, Malaysia, were surveyed for the prevalence of anthracnose disease caused by Colletotrichum species. Diseased samples were randomly collected from 12 infested fields. Anthracnose incidence on bok choy varied from 8 to 36% in different nursery fields. Disease symptoms initially appeared as small water-soaked spots scattered on the leaf petioles of young plants. As these spots increased in size, they developed irregular round spots that turned to sunken grayish brown lesions surrounded by brownish borders. When the lesions were numerous, leaves collapsed. Pale buff to salmon conidial mass and acervuli were observed on well-developed lesions. The acervuli diameter varied in size from 198 to 486 μm, averaging 278.5 μm. Morphological and cultural characteristics of the fungus were examined on potato dextrose agar incubated for 7 days at 25 ± 2°C under constant fluorescent light. Vegetative mycelia were hyaline, septate, branched, and 2 to 7 μm in diameter. The color of the fungal colonies was grayish brown. Conidia were hyaline, aseptate, falcate, apices acute, and 21.8 to 28.5 × 2.6 to 3.4 mm. Setae were pale brown to dark brown, 75 to 155 μm long, base cylindrical, and tapering towards the acute tip. Appressoria were solitary or in dense groups, light to dark brown, entire edge to lobed, roundish to clavate, 6.5 to 14 × 5.8 to 8.6 μm, averaging 9.2 × 6.8 μm, and had a L/W ratio of 1.35. Based on the keys outlined by Mordue 1971 (2) and Sutton 1980 (3), the characteristics of this fungus corresponded to Colletotrichum capsici. Sequence analysis of the ITS-rDNA obtained from the Malaysian strain CCM3 (GenBank Accession No. JQ685746) using primers ITS5 and ITS4 (1) when aligned with deposited sequences from GenBank revealed 99 to 100% sequence identity with C. capsici strains (DQ286158, JQ685754, DQ286156, GQ936210, and GQ369594). A representative strain CCM3 was used for pathogenicity testing. Four non-infected detached leaves of 2-week-old B. chinensis were surface-sterilized and inoculated by placing 10 μl of conidial suspension (106 conidia ml-1) using either the wound/drop or non-wound/drop method, and distilled water was used as a control (1). Leaves were incubated at 25°C, 98% RH. The experiment was repeated twice. Five days after inoculation, typical anthracnose symptoms with acervuli formation appeared on the surface of tissues inoculated with the spore suspension, but not on the water controls. A fungus with the characteristics of C. capsici was recovered from the lesions on the inoculated leaves. Anthracnose caused by C. capsici has been reported on different vegetable crops, but not on bok choy (3). To the best of our knowledge, this is the first report of C. capsici causing anthracnose on bok choy in Malaysia. References: (1) R. Ford et al. Aust. Plant Pathol. 33:559, 2004. (2) J. E. M. Mordue. CMI Description of Pathogenic Fungi and Bacteria. Commonwealth Mycol. Inst., Kew, UK. 1971. (3) B. C. Sutton. The Genus Glomerella and its anamorph Colletotrichum. CAB International, Wallingford, UK, 1992. (4) P. P. Than et al. Plant Pathol. 57:562, 2008.
    Matched MeSH terms: Agar
  4. Almaliky BSA, Abidin MAZ, Kader J, Wong MY
    Plant Dis, 2013 Jan;97(1):143.
    PMID: 30722276 DOI: 10.1094/PDIS-07-12-0627-PDN
    In April and June 2010, coconut seedlings with symptoms of very slow growth, yellowing of leaves, and general abnormal leaf growth were observed in germination beds in Teluk Intan, Perak, Malaysia. The roots were soft, rotten, and brown, extending upward and downward from these lesions. Rhizomorphs and basidiocarps were produced on coconut seeds near the germination eye and identified as Marasmiellus palmivorus according description by Turner (2). Three isolates were obtained by plating surface sterilized symptomatic roots and basidiocarp on malt extract agar (MEA) amended with 85% lactic acid (1 ml added to 11 of the medium). To confirm the identity of the fungus, genomic DNA was extracted from mycelia and basidiocarps of isolates and the large subunit (LSU) region was amplified and sequenced using LR0R/LR7 primers (3). All isolates had identical LSU sequences (GenBank Accession No. JQ654233 to JQ654235). Sequences were identical to each other and 99% similar to a M. palmivorus sequence deposited in the NCBI database (Accession No. AY639434).To confirm pathogenicity, three isolates of M. palmivorus that were obtained from symptomatic plant tissue was inoculated onto seeds of Malaysian Red Dwarf variety. Each isolate was grown in 100 ml of malt extract broth in 250 ml Erlenmeyer flasks and incubated at 27 ± 2°C for 5 days on an orbital shaker (125 rpm). The resulting culture was passed through two layers of sterile cloth. Mycelial suspension was obtained by blending mycelia in 100 ml of sterile water. Seeds were sterilized by soaking in 10% v/v sodium hypochlorite in distilled water for 3 min. The seeds were then rinsed three times over running tap water. The calyx portion of the seed was removed and five holes were made around the germination eye. The seeds were inoculated by injecting 2 ml of suspension into each hole. The control seeds were inoculated with sterile distilled water only. The seeds were transferred to 40-cm diameter plastic pots containing a mixture of sand, soil, and peat in the ratio of 3:2:1, respectively, and steam treated at 100°C for 1.5 h. Pots were placed in the glasshouse with normal exposures to day-night cycles, temperatures of 29 ± 4°C, and high relative humidity (85 to 95%) achieved by spraying water twice daily. After 2 months, 75% of the inoculated seeds failed to germinate. It was speculated that the artificial inoculum was higher than under germination bed conditions. Rhizomorphs and basidiocarps were produced on husk seeds near the germination eye. Seedlings that emerged successfully developed symptoms similar to those observed in the germination bed. No symptoms developed in the noninoculated seeds and seedlings. At 80 days post inoculation, basidiocarps were observed emerging from three diseased seedlings near the germination eye. Three reisolations were made on MEA from root lesions surface sterilized. Pathogenicity tests and LSU sequence analyses indicated that M. palmivorus is the causal agent of the symptoms observed on coconut seedlings. M. palmivorus was first recorded on coconuts and oil palm in the 1920s (1) and attacks the fruit and the petiole on oil palm (2). To our knowledge, this is the first report of M. palmivorus causing post-emergence damping off on coconut seedlings. References: (1) K. G. Singh. A check-list of host and diseases in Malaysia. Ministry of Agriculture and Fisheries, Malaysia, 1973. (2) P. D. Turner. Oil palm diseases and disorders. Oxford University Press. 1981. (3) R. Vilgalys et al. J. Bacteriol. 172:4238, 1990.
    Matched MeSH terms: Agar
  5. Keith LM, Matsumoto TK, McQuate GT
    Plant Dis, 2013 Jul;97(7):990.
    PMID: 30722533 DOI: 10.1094/PDIS-09-12-0886-PDN
    In January 2011, branch samples were collected from langsat (Lansium domesticum Corr.), a fruit from Southeast Asia with an expanding niche market in Hawaii, exhibiting corky bark symptoms similar to that found on rambutan (Nephelium lappaceum) and litchi (Litchi chinensis) (3). The orchard, located along the Hamakua Coast of Hawaii Island, had 5- to 10-year-old trees, all with corky bark symptoms. As the trees matured, the cankers increased in size and covered the branches and racemes, often resulting in little to no fruit production. Scattered along the infected bark tissue were elongated, black ascomata present in the cracks. Ascomata were removed from the cracks using a scalpel blade, placed at the edge of a water agar petri dish and gently rolled along the agar surface to remove bark tissue and other debris. Individual ascomata were placed in 10-μl drops of 10% sodium hypochlorite on fresh water agar for 20 s, removed, and placed on potato dextrose agar petri dishes amended with 25 μg/ml streptomycin. The isolates were kept at 24°C under continuous fluorescent lighting. After 9 days, black pycnidia were present, which produced smooth, hyaline, linear to curved, filiform conidia, 4 to 6 septate (mostly 6), 31.8 to 70.1 × 2.0 to 2.8 μm. The morphological descriptions and measurements were similar to those reported for Dolabra nepheliae (3). The nucleotide sequence of the internal transcribed spacer (ITS) region including ITS1, 5.8S, and ITS2 intergenic spacers was determined for strain P11-1-1and a BLAST analysis of the sequence (GenBank Accession No. JX566449) revealed 99% similarity (586/587 bp) with the sequence of D. nepheliae strain BPI 882442 on N. lappaceum from Honduras. Based on morphology and ITS sequencing, the fungus associated with the cankers was identified as the same causal agent reported on rambutan and pulasan (N. mutabile) from Malaysia (1), and later reported on rambutan and litchi in Hawaii and Puerto Rico (3). Upon closer observations of the diseased samples, sections of corky bark contained at least two larval insects. The beetles were identified as Corticeus sp. (Coleoptera: Tenebrionidae) and Araecerus sp. (Coleoptera: Anthribidae) by the USDA-ARS Systematic Entomology Laboratory (Beltsville, MD). A corky bark disease on the trunk and larger limbs of mature langsat trees in Florida was thought to be caused by Cephalosporium sp. with larvae (Lepidoptera: Tineidae) feeding on the diseased tissue (2). It is not known the extent to which either of the beetle species is associated with L. domesticum in Hawaii or if they play a role in the bark disorder. To our knowledge, this is the first report of Dolabra nepheliae being found on langsat in Hawaii. Effective management practices should be established to avoid potential production losses or spreading the disease to alternative hosts. References: (1) C. Booth and W. P. Ting. Trans. Brit. Mycol. Soc. 47:235, 1964. (2) J. Morton. Langsat. In: Fruits of Warm Climates, p. 201-203. Julia F. Morton, Miami, FL, 1987. (3) A. Y. Rossman et al. Plant Dis. 91:1685, 2007.
    Matched MeSH terms: Agar
  6. Nasehi A, Kadir JB, Esfahani MN, Mahmodi F, Ghadirian H, Ashtiani FA, et al.
    Plant Dis, 2013 May;97(5):689.
    PMID: 30722195 DOI: 10.1094/PDIS-10-12-0901-PDN
    In 2011, a severe gray leaf spot was observed on eggplant (Solanum melongena) in major eggplant growing areas in Malaysia, including the Pahang, Johor, and Selangor states. Disease incidence was >70% in severely infected areas of about 150 ha of eggplant greenhouses and fields examined. Symptoms initially appeared as small (1 to 5 mm diameter), brownish-black specks with concentric circles on the lower leaves. The specks then coalesced and developed into greyish-brown, necrotic lesions, which also appeared on the upper leaves. Eventually, the leaves senesced and were shed. Tissue cut from the edges of leaf spots were surface-sterilized in 1% NaOCl for 2 min, rinsed in sterilized water, dried, and incubated on potato dextrose agar (PDA). Fungal colonies were greyish green to light brown, and produced a yellow pigment. Single, muriform, brown, oblong conidia formed at the terminal end of each conidiophore, were each 21.6 to 45.6 μm long and 11.5 to 21.6 μm wide, and contained 2 to 7 transverse and 1 to 4 longitudinal septa. The conidiophores were tan to light brown and ≤220 μm long. Based on these morphological criteria, 25 isolates of the fungus were identified as Stemphylium solani (1). To produce conidia in culture, 7-day-old single-conidial cultures were established on potato carrot agar (PCA) and V8 juice agar media under an 8-h/16-h light/dark photoperiod at 25°C (4). Further confirmation of the identification was obtained by molecular characterization in which fungal DNA was extracted and the internal transcribed spacer (ITS) region of ribosomal DNA amplified using primers ITS5 and ITS4 (2), followed by direct sequencing. A BLAST search in the NCBI database revealed that the sequence was 99% identical with published ITS sequences for two isolates of S. solani (Accession Nos. AF203451 and HQ840713). The amplified ITS region was deposited in GenBank (JQ736023). Pathogenicity testing of a representative isolate was performed on detached, 45-day-old eggplant leaves of the cv. 125066-X under laboratory conditions. Four fully expanded leaves (one wounded and two non-wounded leaflets/leaf) were placed on moist filter paper in petri dishes, and each leaflet inoculated with a 20-μl drop of a conidial suspension containing 1 × 105 conidia/ml in sterilized, distilled water (3). The leaves were wounded by applying pressure to leaf blades with the serrated edge of forceps. Four control leaves were inoculated similarly with sterilized, distilled water. Inoculated leaves were incubated in humid chambers at 25°C with 95% RH and a 12-h photoperiod. After 7 days, symptoms similar to those observed in the original fields developed on both wounded and non-wounded inoculated leaves, but not on control leaves, and S. solani was reisolated consistently from the symptoms using the same method as the original isolations. Control leaves remained asymptomatic and the fungus was not isolated from these leaves. The pathogenicity testing was repeated with similar results. To our knowledge, this is the first report of S. solani on eggplant in Malaysia. References: (1) B. S. Kim et al. Plant Pathol. J. 20:85, 2004. (2) Y. R. Mehta et al. Curr. Microbiol. 44:323, 2002. (3) B. M. Pryor and T. J. Michailides. Phytopathology 92:406, 2002. (4) E. G. Simmons. CBS Biodiv. Series 6:775, 2007.
    Matched MeSH terms: Agar
  7. Ko Y, Liu CW, Chen CY, Maruthasalam S, Lin CH
    Plant Dis, 2009 Jul;93(7):764.
    PMID: 30764368 DOI: 10.1094/PDIS-93-7-0764A
    Mango (Mangifera indica L.) is grown on approximately 20,000 ha in Taiwan. It is an economically important crop and the income of many fruit farmers comes primarily from mango production. During 2006 and 2007, a stem-end rot disease was observed 1 week after harvest on 28 to 36% of stored mangoes picked from six orchards in the Pingtung, Tainan, and Kaoshiung regions. Two popular mango cultivars, Keitt and Irwin, showed greater susceptibility to this disease, while 'Haden' was found to be moderately susceptible. In storage, symptoms initially appeared as light-to-dark brown lesions surrounding peduncles. Rot symptoms advanced slowly but eventually penetrated the mesocarp, which consequently reduced the commercial value of fruits. The fungus formed abundant pycnidia (0.1 to 0.6 mm in diameter) on infected fruits in advanced stages of symptom development. Pieces of symptomatic fruits plated on acidified potato dextrose agar (PDA) and incubated at 25 ± 1°C consistently yielded the same fungus. A single conidial isolate was cultured. Pycnidia developed on PDA after continuous exposure to light for 9 to 14 days. On the basis of morphological characteristics, the fungus was identified as Phomopsis mangiferae L. (2,3). Pycnidia released two types of conidia: α-conidia (5 to 10 × 2.3 to 4.0 μm) were hyaline and oval to fusoid; and β-conidia (15.0 to 37.5 × 1.3 to 2.5 μm) were hyaline and filiform with characteristic curves. Conidiophores were hyaline, filiform, simple or branched, septate, and 15 to 75 μm long. Cultures incubated under continuous fluorescent light (185 ± 35 μE·m-2·s-1) at 25°C for 3 days were used as inoculum for pathogenicity tests. Five fruits from 'Keitt' were wounded with a sterilized scalpel and each wound (2 × 2 × 2 mm) was inoculated with either a 5-mm mycelium agar plug or a 0.5-ml spore suspension (105 conidia per ml) of the fungus. Five wounded fruits inoculated with 5-mm PDA plugs or sterile water alone served as controls. Inoculated areas were covered with moist, sterile cotton. Fruits were enclosed in plastic bags and incubated at 24°C for 3 days. The test was performed three times. The same symptoms were observed on all inoculated fruits, whereas no decay was observed on control fruits. Reisolations from the inoculated fruits consistently yielded P. mangiferae, thus fulfilling Koch's postulates. This disease has previously been reported in Australia, Brazil, China, Cuba, India, Malaysia, and the United States (1). To our knowledge, this is the first report of P. mangiferae causing stem-end rot disease on mangoes in Taiwan. Our report necessitates taking preventive strategies in the field, prior to or after harvest, to contain postharvest losses in mangoes. References: (1) G. I. Johnson. Page 39 in: Compendium of Tropical Fruit Diseases. R. C. Ploetz et al., eds. The American Phytopathological Society. St. Paul, MN, 1994. (2) R. C. Ploetz, ed. Page 354 in: Diseases of Tropical Fruit Crops. CABI Publishing. Wallingford, UK, 2003. (3) E. Punithalingam. No. 1168 in: Descriptions of Pathogenic Fungi and Bacteria. CMI, Kew, Surrey, UK, 1993.
    Matched MeSH terms: Agar
  8. Ko Y, Chen CY, Yao KS, Liu CW, Maruthasalam S, Lin CH
    Plant Dis, 2008 Aug;92(8):1248.
    PMID: 30769472 DOI: 10.1094/PDIS-92-8-1248B
    In March 2005, a fruit rot disease was found in several commercial strawberry (Fragaria × ananassa Duchesne) fields at Fongyuan, 24.25°N, 120.72°E, in Taichung County in central Taiwan. The disease was rare and was negligible in most cultivated areas. However, disease incidence has increased by 4 to 5% over the last 2 years and causes significant postharvest losses. In storage, symptoms on berries include light brown-to-black, sunken, irregularly shaped lesions. The lesions gradually enlarge and become firm with a dark green-to-black, velvety surface composed of mycelia, conidiophores, and conidia. Twelve single conidial isolates (AF-1 to AF-12) of a fungus were isolated by placing portions of symptomatic fruit from four locations onto acidified potato dextrose agar (PDA) and incubating at 24 ± 1°C. One isolate from each of the four locations, AF-2, 6, 9, and 12, was selected for identification and pathogenicity studies. The fungus was identified as an Alternaria sp. according to the morphological descriptions of A. tenuissima (2,3). Conidiophores were simple or branched, straight or flexuous, septate, pale to light brown, 3.0 to 5.0 μm in diameter, and bore two to six conidia in a chain. Conidia were dark brown, obclavate or oval, and multicellular with seven transverse (in most cases) and numerous longitudinal septa. Conidia were 15.5 to 56.5 μm (average 35.0 μm) long × 6.0 to 15.0 μm (average 11.0 μm) wide at the broadest point. The pathogen was consistently isolated from berries in the field or in storage. Pathogenicity tests were conducted by inoculating 12 surface-sterilized berries with each of the four isolates. Approximately 300 μl of a spore suspension (2 × 105 conidia per ml) was placed at two points on the uninjured surface of each fruit and allowed to dry for 5 min. Control fruits were treated with sterile water. The berries were then enclosed in a plastic bag and incubated at 24 ± 1°C for 2 days. Disease symptoms similar to those described above were observed on 95% of inoculated berries 3 days after inoculation, while no symptoms developed in control berries. Reisolation from the inoculated berries consistently yielded the Alternaria sp. described above. Pathogenicity tests were performed three times. Previously, strawberry fruit rot caused by A. tenuissima was reported from Florida (2) and Malaysia (1), however, to our knowledge, this is the first report of fruit rot of strawberry caused by a species of Alternaria in Taiwan. References: (1) W. D. Cho et al. List of Plant Diseases in Korea. Korean Society of Plant Pathology, 2004. (2) C. M. Howard and E. E. Albregts. Phytopathology 63:938, 1973. (3) R. D. Milholland. Phytopathology 63:1395, 1973.
    Matched MeSH terms: Agar; Fragaria
  9. Keith LM
    Plant Dis, 2008 May;92(5):835.
    PMID: 30769617 DOI: 10.1094/PDIS-92-5-0835B
    Rambutan (Nephelium lappaceum Linn.) is a tropical, exotic fruit that has a rapidly expanding niche market in Hawaii. Diseased rambutan fruit was commonly observed in orchards in the Hilo and Kona districts of Hawaii Island during 2006. In surveys conducted in January, symptoms appeared as dark brown-to-black spots on mature fruit and blackened areas at the base of spinterns (hair-like projections) of mature and immature fruits. Pieces of infected fruit (cv. R167) were surface sterilized for 2 min in 0.5% NaOCl, plated on potato dextrose agar, and incubated at 24 ± 1°C for 7 days. The fungus growing on PDA was pale buff with sparse, aerial mycelium and acervuli containing black, slimy spore masses. All isolates had five-celled conidia. Apical and basal cells were hyaline, while the three median cells were olivaceous; the upper two were slightly darker than the lower one. Conidia (n = 40) were 20.3 ± 0.1 × 6.8 ± 0.1 μm. There were typically three apical appendages averaging 16.8 ± 0.2 μm long. The average basal appendage was 3.8 ± 0.1 μm long. The fungus was initially identified as Pestalotiopsis virgatula (Kleb.) Stey. on the basis of conidial and cultural characteristics (3). The identification was confirmed by molecular analysis of the 5.8S subunit and flanking internal transcribed spacers (ITS1 and ITS2) of rDNA amplified from DNA extracted from single-spore cultures with the ITS1/ITS4 primers (1,4) and sequenced (GenBank Accession No. EU047943). To confirm pathogenicity, agar pieces, 3 mm in diameter, from 7-day old cultures were used as inoculum. Five mature fruit from rambutan cv. R134 were rinsed with tap water, surface sterilized with 0.5% NaOCl for 2 min, wounded with a needle head, inoculated in the laboratory, and maintained in a moist chamber for 7 days. Lesions resembling symptoms that occurred in the field were observed on fruit after 7 days. No symptoms were observed on fruit inoculated with agar media. The fungus reisolated from diseased fruit was identical to the original isolates, confirming Koch's postulates. The disease appears to be widespread in Hawaii. Preharvest symptoms may have the potential to affect postharvest fruit quality if fruits are not stored at the proper conditions. Pestalotiopsis spp. have been reported on rambutan in Malaysia, Brunei, and Australia (2). To my knowledge, this is the first report of P. virgatula causing fruit spots on rambutan in Hawaii. References: (1) G. Caetano-Annolles et al. Curr. Genet. 39:346, 2001. (2) D. F. Farr et al. Fungal Databases. Systematic Botany and Mycology Laboratory. On-line publication. ARS, USDA, 2007. (3) E. F. Guba. Monograph of Pestalotia and Monochaetia. Harvard University Press, Cambridge, MA, 1961. (4) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA. 1990.
    Matched MeSH terms: Agar
  10. Mohd Hussain RH, Afiqah WN, Abdul Ghani MK, Khan NA, Siddiqui R, Anuar TS
    Saudi J Biol Sci, 2021 Apr;28(4):2352-2359.
    PMID: 33911949 DOI: 10.1016/j.sjbs.2021.01.030
    The incidence of Acanthamoeba keratitis has been increasing since the previous decades, especially among contact lens users. This infection is majorly caused by the use of ineffective contact lens disinfecting solution. Thus, this study was conducted to evaluate the in vitro effects of multi-purpose disinfecting solutions (MPDS) against Acanthamoeba trophozoites and cysts. Acanthamoeba genotype T4 isolated from contact lens paraphernalia and an environmental strains were propagated for trophozoite or cyst-containing culture and adjusted in final concentration of 1 × 105 cells/ml. Amoebicidal and cysticidal assays were conducted by incubating trophozoites and cysts with OPTI-FREE® Express®, ReNu® Fresh™, Complete® Multi-Purpose Solution and AVIZOR Unica® Sensitive according to the manufacturer's minimum recommended disinfectant time (MMRDT) for up to 12 h at 30 ⁰C. Trypan blue hemocytometer-based microscopic counts determined amoebicidal and cysticidal effects. The viability of Acanthamoeba trophozoites and cysts was confirmed by re-inoculated them in the 1.5% non-nutrient agar plates. It was found that none of the MPDS showed amoebicidal and cysticidal effects during the MMRDT. However, OPTI-FREE® Express® demonstrated a significant differences in average cell reduction for both stages within MMRDT. When subjected to 12 h exposure, both OPTI-FREE® Express® and ReNu® Fresh™ led to significant reduction in the number of trophozoite and cyst cells. Notably, Complete® Multi-Purpose Solution and AVIZOR Unica® Sensitive did appreciably improve the solution effectiveness towards trophozoite cells when incubated for 12 h. All MPDS were largely ineffective, with 100% survival of all isolates at MMRDT, while OPTI-FREE® Express® showed limited amoebicidal activity against the contact lens paraphernalia isolate, however, it was more against the environmental strains after 12 h incubation time. The commercially available MPDS employed in this research offered minimal effectiveness against the protozoa despite the contact time. Improvement or development of new solution should consider the adjustment of the appropriate disinfectant concentration, adequate exposure time or the incorporation of novel chemical elements, which are effective against Acanthamoeba for accelerated disinfecting and more reduction of potential exposure of contact lens users to Acanthamoeba keratitis.
    Matched MeSH terms: Agar
  11. Ismail IH, Al-Bayaty FH, Yusof EM, Gulam Khan HBS, Hamka FA, Azmi NA
    J Conserv Dent, 2021 02 10;23(5):489-496.
    PMID: 33911359 DOI: 10.4103/JCD.JCD_528_20
    Introduction: Enterococcus faecalis can be found in failed endodontic treatment (FET) even after performing primary endodontic treatment (PET). Calcium hydroxide (Ca(OH)2) cannot fully eliminate this microorganism during PET. Brazilian green propolis (bee glue) was found to be more effective against E. faecalis when compared to Ca(OH)2. A much less studied Malaysian geopropolis (MP) as well as Aloe vera (AV) is antibacterial but is unknown against E. faecalis.

    Objective: The objective of this study is to determine the antimicrobial effects of MP, AV, and MP + AV in comparison with Ca(OH)2 against E. faecalis, as an intracanal medicament.

    Materials and Methods: Antimicrobial activity of MP, AV, MP + AV, Ca(OH)2, and dimethyl sulfoxide was tested against E. faecalis using antimicrobial sensitivity testing, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). The results were analyzed by Kruskal-Wallis test with Mann-Whitney post hoc test and repeated measures analysis of variance with Bonferroni post hoc test (P < 0.05).

    Results: For agar well-diffusion method, MP + AV gave maximum inhibition zone diameter (mean: 8.11 ± 0.015 mm), MP (mean: 6.21 ± 0.046 mm, Ca(OH)2 (mean: 5.5 ± 0.006), and AV (mean: 5.05 ± 0.012) with P < 0.05. MIC for MP + AV was 2 mg/ml, MP at 8 mg/ml, Ca(OH)2 at 8 mg/ml, and AV at 16 mg/ml. The MBC for MP + AV is at 4 mg/ml, MP at 16 mg/ml, Ca(OH)2 at 16 mg/ml, and AV at 32 mg/ml.

    Conclusion: The combination of MP and AV consistently showed better antimicrobial activity compared to MP and AV alone against E. faecalis. The findings suggest that MP and AV used in combination may be an ideal intracanal medicament in FET and PET.

    Matched MeSH terms: Agar
  12. Roslan MAM, Zulkifli NN, Sobri ZM, Zuan ATK, Cheak SC, Abdul Rahman NA
    PLoS One, 2020;15(7):e0232860.
    PMID: 32645001 DOI: 10.1371/journal.pone.0232860
    Limited information is available that seed biopriming with plant growth-promoting Enterobacter spp. play a prominent role to enhance vegetative growth of plants. Contrary to Enterobacter cloacae, Enterobacter hormaechei is a less-studied counterpart despite its vast potential in plant growth-promotion mainly through the inorganic phosphorus (P) and potassium (K) solubilization abilities. To this end, 18 locally isolated bacterial pure cultures were screened and three strains showed high P- and K-solubilizing capabilities. Light microscopy, biochemical tests and 16S rRNA gene sequencing revealed that strains 15a1 and 40a were closely related to Enterobacter hormaechei while strain 38 was closely related to Enterobacter cloacae (Accession number: MN294583; MN294585; MN294584). All Enterobacter spp. shared common plant growth-promoting traits, namely nitrogen (N2) fixation, indole-3-acetic acid production and siderophore production. The strains 38 and 40a were able to produce gibberellic acid, while only strain 38 was able to secrete exopolysaccharide on agar. Under in vitro germination assay of okra (Abelmoschus esculentus) seeds, Enterobacter spp. significantly improved overall germination parameters and vigor index (19.6%) of seedlings. The efficacy of root colonization of Enterobacter spp. on the pre-treated seedling root tips was confirmed using Scanning Electron Microscopy (SEM). The pot experiment of bioprimed seeds of okra seedling showed significant improvement of the plant growth (> 28%) which corresponded to the increase of P and K uptakes (> 89%) as compared to the uninoculated control plants. The leaf surface area and the SPAD chlorophyll index of bioprimed plants were increased by up to 29% and 9% respectively. This report revealed that the under-explored species of P- and K-solubilizing Enterobacter hormaechei sp. with multiple plant beneficial traits presents a great potential sustainable approach for enhancement of soil fertility and P and K uptakes of plants.
    Matched MeSH terms: Agar
  13. Amirah Nadiah Ali, Mohd Syahmi Salleh, Ahmad Fahmi Harun, Muhamad Ashraf Rostam
    MyJurnal
    Increasing risk of antibiotic resistance of pathogenic bacteria has led to the exploration of alternative antibiotics derived from leaves of medicinal plants such as the fig (Ficus carica L.). The aim of this study was to determine the antimicrobial activity of the methanolic extract of fig leaves grown under Malaysian tropical environment against pathogenic bacteria linked to antibiotic resistance namely the Staphylococcus aureus and Escherechia coli. The methanolic extraction was performed by using soxhlet apparatus. The disc diffusion method was used to measure inhibition zone diameter on the Mueller-Hinton agar plate. Staphylococcus aureus displayed the highest diameter of inhibition zone against the extract at concentration of 900 mg/ml whilst Escherechia coli displayed the highest diameter of inhibition zone against both the 100% crude extract and 700 mg/ml, respectively. This study therefore highlighted the potential of developing alternative antibiotics derived from the methalonic extract of locally grown fig plant.
    Matched MeSH terms: Agar
  14. Nor Amerulah Nor Mohamad, Suhaida Salleh, Hamzah Abdul Aziz
    Borneo Akademika, 2019;3(2):12-22.
    MyJurnal
    Black pod rot is the most economically important disease of cocoa in Malaysia which is
    mainly caused by a highly polyphagous Phytophthora species, called Phytophthora palmivora.
    The fungus could attack all parts of the cocoa plant organs and caused various diseases at
    any growth stage from seedling until the mature stages, especially during raining season. The
    application of synthetic fungicides has been widely recommended to manage the disease but
    their repeated use had led to other problems such as environmental, human health and
    development of fungicide resistance issues. This study isolated and identified Phytopththora
    isolate from a cocoa pod sample based on micro-morphological characters. Besides, the
    present investigation was undertaken to screen for the antifungal potency of different weed
    extracts against the Phytophthora pathogen using poisoned food technique. The fungal isolate
    was successfully recovered from pod tissues of clone PBC123 on 20% tomato juice agar
    culture (20T). Only one out of ten weed extracts tested showed a significant in vitro inhibitory
    effect towards mycelial growth of Phytophthora isolate, which was aqueous crude leaf extract
    of Solanum torvum (42.68%). This study indicated that the potential of weed extracts in the
    management of Phytophthora diseases, and may offer more natural, effective and economical
    control methods.
    Matched MeSH terms: Agar
  15. Adam Zafdri Md Zali, Rashidah Iberahim
    MyJurnal
    Pseudomonas aeruginosa and Staphylococcus aureus are types of bacteria known to cause bacterial keratitis. Pseudomonas aeruginosa causes bacterial keratitis by adhering to the surface of the contact lenses, when the P. aeruginosa are in contact with the eye, resulting in infectious keratitis. As for Staphylococcus aureus, when there is a predisposing factor such as wearing expired or extended use of contact lenses (contact lenses that can be used continually for up to one week even while sleeping) weaken the individual defences and leads to the development of bacterial keratitis. Both bacteria are capable to infect eye cornea and lead to bacterial keratitis through contact lenses wearer. The findings of this study provide information on the importance of routine practices in handling contact lenses to help reduce the incidence of bacterial keratitis caused by wear contact lenses in an individual. The side effect of wearing contact lenses such as redness of the eye and keratitis due to the infection by pathogenic bacteria which comes from the behavior and low hygiene level management of individual had led the study to create awareness to contact lenses wearer. In this study, 25 soft and hard contact lenses with purposed for colored or toric contact lenses were obtained among UiTM Negeri Sembilan students. The users required to answer the questionnaire form regarding the type, behavior, and routine practices of their contact lenses. Pathogenic bacteria were isolated using the cotton swab technique and cultured on nutrient broth. The streak technique was used to cultured bacteria from broth to nutrient agar, blood agar, and MacConkey agar. Later, the identification of bacteria was carried out using biochemical tests and microscopic observation. From the laboratory results, 84% of the tested contact lenses contained pathogenic bacteria on their surface. These findings concluded that the presences of pathogenic microorganisms on the contact lenses used closely related to the behavior in handling and hygenic practices level by the contact lenses users.
    Matched MeSH terms: Agar
  16. Lim EL, Siow RS, Abdul Rahim R, Ho CL
    Mar Biotechnol (NY), 2016 Apr;18(2):189-200.
    PMID: 26631182 DOI: 10.1007/s10126-015-9680-6
    Many bacterial epiphytes of agar-producing seaweeds secrete agarase that degrade algal cell wall matrix into oligoagars which elicit defense-related responses in the hosts. The molecular defense responses of red seaweeds are largely unknown. In this study, we surveyed the defense-related transcripts of an agarophyte, Gracilaria changii, treated with β-agarase through next generation sequencing (NGS). We also compared the defense responses of seaweed elicited by agarase with those elicited by an agarolytic bacterium isolated from seaweed, by profiling the expression of defense-related genes using quantitative reverse transcription real-time PCR (qRT-PCR). NGS detected a total of 391 differentially expressed genes (DEGs) with a higher abundance (>2-fold change with a p value <0.001) in the agarase-treated transcriptome compared to that of the non-treated G. changii. Among these DEGs were genes related to signaling, bromoperoxidation, heme peroxidation, production of aromatic amino acids, chorismate, and jasmonic acid. On the other hand, the genes encoding a superoxide-generating NADPH oxidase and related to photosynthesis were downregulated. The expression of these DEGs was further corroborated by qRT-PCR results which showed more than 90 % accuracy. A comprehensive analysis of their gene expression profiles between 1 and 24 h post treatments (hpt) revealed that most of the genes analyzed were consistently upregulated or downregulated by both agarase and agarolytic bacterial treatments, indicating that the defense responses induced by both treatments are highly similar except for genes encoding vanadium bromoperoxidase and animal heme peroxidase. Our study has provided the first glimpse of the molecular defense responses of G. changii to agarase and agarolytic bacterial treatments.
    Matched MeSH terms: Agar
  17. Hossain K, Quaik S, Ismail N, Rafatullah M, Avasan M, Shaik R
    Iran J Biotechnol, 2016 Sep;14(3):154-162.
    PMID: 28959331 DOI: 10.15171/ijb.1216
    BACKGROUND: Application of membrane technology to wastewater treatment has expanded over the last decades due to increasingly stringent legislation, greater opportunities for water reuse/recycling processes and continuing advancement in membrane technology.

    OBJECTIVES: In the present study, a bench-scale submerged microfiltration membrane bioreactor (MBR) was used to assess the treatment of textile wastewater.

    MATERIALS AND METHODS: The decolorization capacity of white-rot fungus coriolus versicolor was confirmed through agar plate and liquid batch studies. The temperature and pH of the reactor were controlled at 29±1°C and 4.5±2, respectively. The bioreactor was operated with an average flux of 0.05 m.d(-1) (HRT=15hrs) for a month.

    RESULTS: Extensive growth of fungi and their attachment to the membrane led to its fouling and associated increase of the transmembrane pressure requiring a periodic withdrawal of sludge and membrane cleaning. However, stable decoloration activity (approx. 98%), BOD (40-50%), COD (50-67%) and total organic carbon (TOC) removal (>95%) was achieved using the entire system (fungi + membrane), while the contribution of the fungi culture alone for TOC removal, as indicated by the quality of the reactor supernatant, was 35-50% and 70%, respectively.

    CONCLUSIONS: The treated wastewater quality satisfied the requirement of water quality for dyeing and finishing process excluding light coloration. Therefore, textile wastewater reclamation and reuse is a promising alternative, which can both conserve or supplement the available water resource and reduce or eliminate the environmental pollution.

    Matched MeSH terms: Agar
  18. Melinda, Mei Lin Lau, Edmund, Sim Ui Hang
    MyJurnal
    Association between the expression of ribosomal protein (RP) genes and cancer is widely known. More specifically, the extra-ribosomal functions of RPs have been linked to carcinogenesis. The ribosomal protein gene, eL14 has been reported to be associated with malignancy of the colorectum, albeit of mechanism yet unclear. Its expression in cells derived from different tissue origin of colorectal carcinoma (CRC) has never been explored. Therefore, this study aims to comparatively analyse the expression pattern of eL14 between two different CRC cell lines (DLD-1 and HCT116). It involved a conventional gene expression analysis, the Reverse-Transcriptase PCR (RT-PCR) assays. Products of RT-PCR assay were resolved via an agarose gel electrophoresis method, and band intensities of amplicons were documented and quantified using TotalLab Quant software. We observed differential expression patterns of eL14 between DLD-1 and HCT116 cells, but statistical analysis revealed insignificant differences. Therefore, the relevance of eL14 as a biomarker to distinguish between different colorectal cancer cells is suggestive but not conclusive.
    Matched MeSH terms: Electrophoresis, Agar Gel
  19. Kqueen, Cheah Yoke, Maryam Abdulla Seif, Mohamed Ikhtifar Rafi, Lim, Wei Meng, Ling, Clemente Michael Wong Vui, Tan, Geok Yuan Annie
    MyJurnal
    Global warming is the main concern in today’s century as it comes with numerous side effects to the natural environment. Open Top Chambers (OTC) consist of metal constructions with transparent vertical side-walls and a frustum on top. An opening in the middle of the frustum allows an air exchange to reduce temperature and humidity effects in the chamber. The size of the open top chamber which is located in Universiti Putra Malaysia is slanted 60o, 50cm tall, 2.08m basal diameter hexagon chamber. The Open Top Chamber experiments were carried out to determine how much global warming has affected and is still affecting the temperature, pH, the moisture and the growth of the microbes in the tropical soil. The aim of this study is to elucidate the effects of temperature increase on the soil microbes’ population and on the pH of the soil. The study was conducted to observe the effect of heat on the population of soil microbes and the pH of the soil which was collected on the same day for 6 consecutive months. The microbes from the samples were grown on agar plates. The population of microbes on the plates were used as values were for Colony Forming Unit (CFU) value calculations. The effects of OTCs on mean temperature showed a large range of CFU values throughout the 6 months but did not differ significantly between studies. Increases in mean monthly and diurnal temperature were strongly related, indicating that the presence of warming effect by the OTCs. Such predictive power allows a better mechanistic understanding of observed biotic response to experimental warming. This study will be useful for the understanding of the global warming effect on microbes. The Open Top Chamber experiment has proven to be one of the effective model for global warming research and data collected especially on the growth of soil microbial obtained would be of great use for further experiments.
    Matched MeSH terms: Agar
  20. Yoga Latha, L., Darah, I., Sasidharan, S., Jain, K.
    Malays J Nutr, 2009;15(2):223-231.
    MyJurnal
    Chemical preservatives have been used in the food industry for many years. However, with increased health concerns, consumers prefer additive-free products or food preservatives based on natural products. This study evaluated antimicrobial activities of extracts from Emilia sonchifolia L. (Common name: lilac tassel flower), Tridax procumbens L. (Common name: tridax daisy) and Vernonia cinerea L. (Common name: Sahadevi), belonging to the Asteracea family, to explore their potential for use against general food spoilage and human pathogens so that new food preservatives may be developed. Three methanol extracts of these plants were tested in vitro against 20 bacterial species, 3 yeast species, and 12 filamentous fungi by the agar diffusion and broth dilution methods. The V. cinerea extract was found to be most effective against all of the tested organisms and the methanol fraction showed the most significant (p < 0.05) antimicrobial
    activity among all the soluble fractions tested. The minimum inhibitory concentrations (MICs) of extracts determined by the broth dilution method ranged from 1.56 to 100.00mg/mL. The MIC of methanol fraction was the lowest in comparison to the other four extracts. The study findings indicate that bioactive natural products from these plants may be isolated for further testing as leads in the development of new pharmaceuticals in food preservation as well as natural plant-based medicine.
    Matched MeSH terms: Agar
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