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  1. Fulltext First Report of Powdery Mildew caused by Podosphaera xanthii on Euphorbia tithymaloides in Malaysia
    Ismail SI, Roslen A
    Plant Dis, 2020 Dec 16.
    PMID: 33325746 DOI: 10.1094/PDIS-08-20-1700-PDN
    Euphorbia tithymaloides L. (zig-zag plant) is a succulent, perennial shrub belonging to the Euphorbiaceae family and is widely cultivated in Malaysia for ornamental purposes and commercial values. In June 2019, typical symptoms of powdery mildew were observed on over 50% of the leaves of E. tithymaloides in a garden at Universiti Putra Malaysia, Serdang city of Selangor province, Malaysia. Initial symptoms included circular to irregular white powdery fungal colonies on both leaf surfaces and later covered the entire leaf surface. Severely infected leaves became necrotic, distorted and senesced. A voucher specimen Ma (PM001-Ma) was deposited in the Mycology laboratory, Faculty of Agriculture, UPM. Microscopic observation showed hyphae hyaline, branched, thin-walled, smooth, 3 to 6 µm wide with nipple-shaped appressoria. Conidiophores were straight, measured 30 to 90 μm long × 8 to 12 μm wide and composed of a cylindrical foot cell, 50 to 75 μm long. Conidia formed in chains were hyaline, ellipsoid to oval with fibrosin bodies, measured 25 to 36 × 16 to 20.1 μm in size and chasmothecia were not observed on the infected leaves. Genomic DNA was directly isolated from mycelia and conidia of isolate Ma using DNeasy Plant Mini Kit (Qiagen, USA). The universal primer pair ITS4/ITS5 of rDNA (White et al. 1990) was used for amplification and the resulting 569-bp sequence was deposited in GenBank (Accession no. MT704550). A BLAST nucleotide search revealed 100% similarity with that of Podosphaera xanthii on Momordica charantia wild from Taiwan (Accession no. KM505135) (Kirschner and Liu 2015). Both the morphological characteristics of the anamorph and ITS sequence data support the identification of this powdery mildew on E. tithymaloides as Podosphaera xanthii (Castagne) U. Braun & Shishkoff (Braun and Cook 2012). A pathogenicity test was conducted by gently pressing the infected leaves onto young leaves of five healthy potted plants. Five noninoculated plants were used as controls. The inoculated plants were maintained in a greenhouse at 25 ± 2°C and the test was repeated. Seven days after inoculation, white powdery symptoms were observed similar to those on the naturally infected leaves, while control plants remained asymptomatic. The fungus on the inoculated leaves was morphologically and molecularly identical to the fungus on the original specimens. Sequence alignments were made using MAFFT v.7.0 (Katoh et al. 2019) and a maximum likelihood phylogram was generated by MEGA v.7.0 (Kumar et al. 2016). Isolate Ma grouped in a strongly supported clade (100% bootstrap value) with the related species of P. xanthii available in GenBank based on the ITS region. Powdery mildew caused by P. xanthii has been reported as a damaging disease that can infect a broad range of plants worldwide (Farr and Rossman 2020). It also has been recently reported on Sonchus asper in China (Shi et al. 2020). According to our knowledge, this is the first report of powdery mildew caused by P. xanthii on E. tithymaloides worldwide. The occurrence of powdery mildew on E. tithymaloides could pose a serious threat to the health of this plant, resulting in death and premature senescence of young leaves.
  2. Fulltext The Influence of Forefoot Bending Stiffness of Futsal Shoes on Multiple V-Cut Run Performance
    Ismail SI, Nunome H, Tamura Y
    Front Psychol, 2021;12:625079.
    PMID: 34149512 DOI: 10.3389/fpsyg.2021.625079
    A forefoot bending stiffness (FBS) property of footwear is known to benefit athletes in running performance. To date, the efficacy of bending stiffness on performance is rather unknown from the perspective of futsal shoes. This study investigates the influence of bending stiffness property of three commercial futsal shoes on change of direction run resultant performance. Nineteen university level athletes participated in the human performance test (multiple V-cut change of direction run) on a hardwood flooring facility using three pairs of futsal shoes (i.e., S1, S2, and S3) with different models but similar in outsole material (S1-mass: 311 g, heel-to-toe drop: 10 mm, friction coefficient, 1.25; S2-mass: 232 g, heel-to-toe drop: 8 mm, friction coefficient: 1.34; and S3-mass: 276 g, heel-to-toe drop: 7 mm, friction coefficient: 1.30). The FBS properties for each shoe were mechanically measured. Results from the analysis of variance indicated that there was a significant difference of FBS value among the three shoes (S1: 0.32 Nm/deg., S2: 0.26 Nm/deg., and S3: 0.36 Nm/deg.) [F(2,8) = 28.50 (p < 0.001)]. Shoes with relatively higher shoe-playing surface friction coefficient (S2 and S3) had significant impact on the V-cut performance (p < 0.05) when compared with the shoe with lower friction coefficient (S1). In contrast to the literature, the shoe with the lowest FBS (S2) did not suffer any detriments on the resultant performance in the test conducted. These findings suggested that there could be other performance limiting factors, such as the friction coefficient, rather than FBS that have greater influence on the test outcomes.
  3. Fulltext First Report of Fusarium incarnatum-equiseti Species Complex Causing Leaf Spot on Rockmelon (Cucumis melo L.) in Malaysia
    Ismail SI, Noor Asha NA, Zulperi D
    Plant Dis, 2020 Nov 02.
    PMID: 33135990 DOI: 10.1094/PDIS-06-20-1380-PDN
    Rockmelon, (Cucumis melo L.) is an economically important crop cultivated in Malaysia. In October 2019, severe leaf spot symptoms with a disease incidence of 40% were observed on the leaves of rockmelon cv. Golden Champion at Faculty of Agriculture, Universiti Putra Malaysia (UPM). Symptoms appeared as brown necrotic spots, 10 to 30 mm in diameter, with spots surrounded by chlorotic halos. Pieces (5 x 5 mm) of diseased tissue were sterilized with 0.5% NaOCl for 1 min, rinsed three times with sterile distilled water, plated onto potato dextrose agar (PDA) and incubated at 25°C for 7 days with a 12-h photoperiod. Nine morphologically similar isolates were obtained by using single spore isolation technique and a representative isolate B was characterized further. Colonies were abundant, whitish aerial mycelium with orange pigmentation. The isolates produced macroconidia with 5 to 6 septa, a tapered with pronounced dorsiventral curvature and measured 25 to 30 μm long x 3 to 5 μm wide. Microconidia produced after 12 days of incubation were single-celled, hyaline, ovoid, nonseptate, and 1.0 to 3.0 × 4.0 to 10.0 µm. Morphological characteristics of the isolates were similar to the taxonomic description of Fusarium equiseti (Leslie and Summerell 2006). Genomic DNA was extracted from fresh mycelium using DNeasy Plant Mini kit (Qiagen, USA). To confirm the identity of the fungus, two sets of primers, ITS4/ITS5 (White et al. 1990) and TEF1-α, EF1-728F/EF1-986R (Carbone and Kohn 1999) were used to amplify complete internal transcribed spacer (ITS) and partial translation elongation factor 1-alpha (TEF1-α) genes, respectively. BLASTn search in the NCBI database using ITS and TEF-1α sequences revealed 99 to 100% similarities with species of both F. incarnatum and F. equiseti. BLAST analysis of these in FUSARIUM-ID database showed 100% and 99% similarity with Fusarium incarnatum-F. equiseti species complex (FIESC) (NRRL34059 [EF-1α] and NRRL43619 [ITS]) respectively (Geiser et al. 2004). The ITS and TEF1-α sequences were deposited in GenBank (MT515832 and MT550682). The isolate was identified as F. equiseti, which belongs to the FIESC based on morphological and molecular characteristics. Pathogenicity was conducted on five healthy leaves of 1-month-old rockmelon cv. Golden Champion grown in 5 plastic pots filled with sterile peat moss. The leaves were surface-sterilized with 70% ethanol and rinsed twice with sterile-distilled water. Then, the leaves were wounded using 34-mm-diameter florist pin frog and inoculated by pipetting 20-μl conidial suspension (1 × 106 conidia/ml) of 7-day-old culture of isolate B onto the wound sites. Control leaves were inoculated with sterile-distilled water only. The inoculated plants were covered with plastic bags for 5 days and maintained in a greenhouse at 25 °C, 90% relative humidity with a photoperiod of 12-h. After 7 days, inoculated leaves developed necrotic lesions similar to the symptoms observed in the field while the control treatment remained asymptomatic. The fungus was reisolated from the infected leaves and was morphologically identical to the original isolate. F. equiseti was previously reported causing fruit rot of watermelon in Georgia (Li and Ji 2015) and China (Li et al. 2018). This pathogen could cause serious damage to established rockmelon as it can spread rapidly in the field. To our knowledge, this is the first report of a member of the Fusarium incarnatum-F.equiseti species complex causing leaf spot on Cucumis melo in Malaysia.
  4. Fulltext First Report of Lasiodiplodia theobromae Causing Postharvest Fruit Rot on Guava (Psidium guajava) in Malaysia
    Zee KY, Asib N, Ismail SI
    Plant Dis, 2021 Apr 14.
    PMID: 33851868 DOI: 10.1094/PDIS-12-20-2732-PDN
    Guava (Psidium guajava L.) is an economically important tropical fruit crop and is cultivated extensively in Malaysia. In September and October 2019, postharvest fruit rot symptoms were observed on 30% to 40% of guava fruit cv. Kampuchea in fruit markets of Puchong and Ipoh cities in the states of Selangor and Perak, Malaysia. Initial symptoms appeared as brown, irregular, water-soaked lesions on the upper portion of the fruit where it was attached to the peduncle. Subsequently, lesions then progressed to cover the whole fruit (Fig.1A). Lesions were covered with an abundance of black pycnidia and grayish mycelium. Ten symptomatic guava fruit were randomly collected from two local markets for our investigation. For fungal isolation, small fragments (5×5 mm) were excised from the lesion margin, surface sterilized with 0.5% NaOCl for 2 min, rinsed three times with sterile distilled water, placed on potato dextrose agar (PDA) and incubated at 25 °C with 12-h photoperiod for 2-3 days. Eight single-spore isolates with similar morphological characteristics were obtained and two representative isolates (P8 and S9) were characterized in depth. Colonies on PDA were initially composed of grayish-white aerial mycelium, but turned dark-gray after 7 days (Fig. 1B). Abundant black pycnidia were observed after incubation for 4 weeks. Immature conidia were hyaline, aseptate, ellipsoid, thick-walled, and mature conidia becoming dark brown and 1-septate with longitudinal striations, 25.0 - 27.0 ± 2.5 × 13.0 - 14.0 ± 1.0 μm (n = 30) (Fig.1C, D). On the basis of morphology, both representative isolates were identified as Lasiodiplodia theobromae (Pat.) Griffon & Maubl. (Alves et al. 2008). For molecular identification, genomic DNA of the two isolates was extracted using the DNeasy plant mini kit (Qiagen, USA). The internal transcribed spacer (ITS) region of rDNA and translation elongation factor 1-alpha (EF1-α) genes were amplified using ITS5/ITS4 and EF1-728F/EF1-986R primer set, respectively (White et al. 1990, Carbone and Kohn 1999). BLASTn analysis of the resulting ITS and EF1-α sequences indicated 100% identity to L. theobromae ex-type strain CBS 164.96 (GenBank accession nos: AY640255 and AY640258, respectively) (Phillips et al. 2013). The ITS (MW380428, MW380429) and EF1-α (MW387153, MW387154) sequences were deposited in GenBank. Phylogenetic analysis using the maximum likelihood based on the combined ITS-TEF sequences indicated that the isolates formed a strongly supported clade (100% bootstrap value) to the related L. theobromae (Kumar et al. 2016) (Fig.2). A pathogenicity test of two isolates was conducted on six healthy detached guava fruits per isolate. The fruit were surface sterilized using 70% ethanol and rinsed twice with sterile water prior inoculation. The fruit were wound-inoculated using a sterile needle according to the method of de Oliveira et al. (2014) and five-mm-diameter mycelial agar plugs from 7-days-old PDA culture of the isolates were placed onto the wounds. Six additional fruit were wound inoculated using sterile 5-mm-diameter PDA agar plugs to serve as controls. Inoculated fruit were placed in sterilized plastic container and incubated in a growth chamber at 25 ± 1 °C, 90% relative humidity with a photoperiod of 12-h. The experiment was conducted twice. Five days after inoculation, symptoms as described above developed on the inoculated sites and caused a fruit rot, while control treatment remained asymptomatic. L. theobromae was reisolated from all symptomatic tissues and confirmed by morphological characteristics and confirmed by PCR using ITS region. L. theobromae has recently been reported to cause fruit rot on rockmelon in Thailand (Suwannarach et al. 2020). To our knowledge, this is the first report of L. theobromae causing postharvest fruit rot on guava in Malaysia. The occurrence of this disease needs to be monitored as this disease can reduce the marketable yield of guava. Preventive strategies need to be developed in the field to reduce postharvest losses.
  5. Fulltext First Report of Nigrospora sphaerica causing leaf spot on watermelon (Citrullus lanatus L.) in Malaysia
    Ismail SI, Abd Razak NF
    Plant Dis, 2020 Sep 23.
    PMID: 32967557 DOI: 10.1094/PDIS-07-20-1491-PDN
    Watermelon (Citrullus lanatus L.) is widely cultivated and consumed in Malaysia for its nutritional value. In June 2018, nearly 40% of the 'Red Rocky' watermelon plants in experimental plots of the research farm at Faculty of Agriculture, UPM Serdang, Selangor, Malaysia had leaf spot symptoms. Leaf spots were small, ranging 5 to 30 mm, yellow to brown, and circular to irregular in shape. With ages, the leafspots gradually enlarged and coalesced. To investigate the disease, ten symptomatic leaves were collected from the experimental plots. Diseased tissues (5 x 5 mm) were excied and surface sterilized with 0.5% sodium hypochlorite (NaOCl) for 2 min, rinsed twice with sterile distilled water, plated on potato dextrose agar (PDA), and incubated at 25 °C for 5 days. A total of ten isolates with similar colony morphologies were obtained from tissue samples. A single representative isolate "F" was further characterized by molecular analysis. All colonies were initially white in color, but later turned gray to black upon sporulation after 7 days. Conidia were produced in culture and were single-celled, black, smooth-walled, spherical in shape measuring 11.4 to 14 μm x 13.8 to 19 μm in diameter (n=40). These were borne on hyaline vesicles at the tip of a conidiophore. For molecular identification, genomic DNA was extracted from fresh mycelium of isolate F using DNeasy Plant Mini kit (Qiagen, Germantown, MD, USA). The internal transcribed spacer (ITS) region of rDNA and the translation elongation factor 1-alpha (TEF1-α) gene were amplified using the ITS5/ITS4 (White et al. 1990) and EF1-728F/EF1-986R primer sets (Carbone and Kohn 1999), respectively. BLASTn analysis of the ITS sequence revealed 100% identity (526 bp out of 526 bp) to Nigrospora sphaerica (GenBank Accession no. HQ608063). TEF1-α sequence had 100% identity (494 bp out 494 bp) with N. sphaerica (GenBank Accession no. MN995332). The resulting sequences were deposited in GenBank (ITS: Accession no. MK544066; TEF1-α Accession no. MT708197). Based on morphological and molecular characteristics, isolate "F" was identified as Nigrospora sphaerica (Sacc.) Mason (Chen et al. 2018). A pathogenicity test was conducted on five healthy leaves of five one-month-old watermelon 'Red Rocky' plants grown in a greenhouse. Leaves were wounded using a 34-mm-diameter florist pin frog and spray-inoculated until runoff with a conidial suspension (1 × 106 conidia/ml) of a 7-day-old culture. Five leaves from additional 2 plants were sprayed with sterile distilled water to serve as controls. Inoculated plants were covered with polyethylene bags for 48 h to maintain high humidity. Ten days post-inoculation, symptoms on inoculated leaves developed brown-to-black lesions similar to those observed in the field, while control leaves remained asymptomatic. N. sphaerica was re-isolated from all symptomatic tissues confirming Koch's postulates. N. sphaerica is distributed on a wide range of hosts and has been reported from 40 different host genera including monocotyledonous and dicotyledonous hosts (Wang et al. 2017). N. sphaerica has been reported to cause leaf spot of date palm in Pakistan (Alam et al. 2020) and kiwifruit in China (Chen et al. 2016). To our knowledge, this is the first report of N. sphaerica causing leaf spot of watermelon in Malaysia. This new disease could reduce fruit quality since sweetness and ripening are dependent on healthy foliage. Additionally, this disease can cause premature defoliation which would also reduce watermelon productivity.
  6. Fulltext First report of Colletotrichum siamense Causing Blossom Blight on Thai basil (Ocimum basilicum L.) in Malaysia
    Ismail SI, Rahim NA, Zulperi D
    Plant Dis, 2020 Dec 21.
    PMID: 33349005 DOI: 10.1094/PDIS-06-20-1371-PDN
    Thai basil (Ocimum basilicum L.) is widely cultivated in Malaysia and commonly used for culinary purposes. In March 2019, necrotic lesions were observed on the inflorescences of Thai basil plants with a disease incidence of 60% in Organic Edible Garden Unit, Faculty of Agriculture in the Serdang district (2°59'05.5"N 101°43'59.5"E) of Selangor province, Malaysia. Symptoms appeared as sudden, extensive brown spotting on the inflorescences of Thai basil that coalesced and rapidly expanded to cover the entire inflorescences. Diseased tissues (4×4 mm) were cut from the infected lesions, surface disinfected with 0.5% NaOCl for 1 min, rinsed three times with sterile distilled water, placed onto potato dextrose agar (PDA) plates and incubated at 25°C under 12-h photoperiod for 5 days. A total of 8 single-spore isolates were obtained from all sampled inflorescence tissues. The fungal colonies appeared white, turned grayish black with age and pale yellow on the reverse side. Conidia were one-celled, hyaline, subcylindrical with rounded end and 3 to 4 μm (width) and 13 to 15 μm (length) in size. For fungal identification to species level, genomic DNA of representative isolate (isolate C) was extracted using DNeasy Plant Mini Kit (Qiagen, USA). Internal transcribed spacer (ITS) region, calmodulin (CAL), actin (ACT), and chitin synthase-1 (CHS-1) were amplified using ITS5/ITS4 (White et al. 1990), CL1C/CL2C (Weir et al. 2012), ACT-512F/783R, and CHS-79F/CHS-345R primer sets (Carbone and Kohn 1999), respectively. A BLAST nucleotide search of ITS, CHS-1, CAL and ACT sequences showed 100% similarity to Colletotrichum siamense ex-type cultures strain C1315.2 (GenBank accession nos. ITS: JX010171 and CHS-1: JX009865) and isolate BPDI2 (CAL: FJ917505, ACT: FJ907423). The ITS, CHS-1, CAL and ACT sequences were deposited in GenBank as accession numbers MT571330, MW192791, MW192792 and MW140016. Pathogenicity was confirmed by spraying a spore suspension (1×106 spores/ml) of 7-day-old culture of isolate C onto 10 healthy inflorescences on five healthy Thai basil plants. Ten infloresences from an additional five control plants were only sprayed with sterile distilled water and the inoculated plants were covered with plastic bags for 2 days and maintained in a greenhouse at 28 ± 1°C, 98% relative humidity with a photoperiod of 12-h. Blossom blight symptoms resembling those observed in the field developed after 7 days on all inoculated inflorescences, while inflorescences on control plants remained asymptomatic. The experiment was repeated twice. C. siamense was successfully re-isolated from the infected inflorescences fulfilling Koch's postulates. C. siamense has been reported causing blossom blight of Uraria in India (Srivastava et al. 2017), anthracnose on dragon fruit in India and fruits of Acca sellowiana in Brazil (Abirami et al. 2019; Fantinel et al. 2017). This pathogen can cause a serious threat to cultivation of Thai basil and there is currently no effective disease management strategy to control this disease. To our knowledge, this is the first report of blossom blight caused by C. siamense on Thai basil in Malaysia.
  7. Phenology of Infection on Apple Fruit by Sooty Blotch and Flyspeck Species in Iowa Apple Orchards
    Ismail SI, Batzer JC, Harrington TC, Gleason ML
    Plant Dis, 2016 Feb;100(2):352-359.
    PMID: 30694131 DOI: 10.1094/PDIS-02-15-0137-RE
    Sooty blotch and flyspeck (SBFS) is a fungal disease complex that can cause significant economic losses to apple growers by blemishing the fruit surface with dark-colored colonies. Little is known about the phenology of host infection for this diverse group of epiphytes. In 2009 and 2010, we investigated the timing of infection of apple fruit by SBFS species in six commercial apple orchards in Iowa. Five trees in each orchard received no fungicide sprays after fruit set. Within 3 weeks after fruit set, 60 apples per tree were covered with Japanese fruit bags to minimize inoculum deposition. Subsequently, a subsample of bagged apples was exposed for a single 2-week-long period and then rebagged for the remainder of the growing season. Experimental treatments included seven consecutive 2-week-long exposure periods; control treatments were apples that were either bagged or exposed for the entire season. After apples had been stored at 2°C for 6 weeks following harvest, all SBFS colonies on the apples were identified to species using a PCR-RFLP protocol. A total of 15 species were identified. For the seven most prevalent species, the number of infections per cm2 of fruit surface was greatest on apples that had been exposed early in the season. Two SBFS species, Peltaster fructicola and Colletogloeopsis-like FG2, differed significantly from each other in time required to attain 50% of the total number of colonies per apple, and analysis of variance indicated a significant interaction of SBFS taxon with exposure period. Our findings are the first evidence of species-specific patterns in timing of SBFS inoculum deposition and infection on apple fruit, and strengthen previous observations that most SBFS infections resulting in visible colonies at harvest develop from infections that occur early in the fruit development period. By defining taxon-specific phenological patterns of fruit infection, our findings, when combined with knowledge of region-specific patterns of taxon prevalence, provide a foundation for development of more efficient and cost-effective SBFS management tactics.
  8. Fulltext Suppression of Xanthomonas oryzae pv. oryzae biofilm formation by Acacia mangium methanol leaf extract
    Shafiei SNS, Ahmad K, Ikhsan NFM, Ismail SI, Sijam K
    Braz J Biol, 2020 2 20;81(1):11-17.
    PMID: 32074168 DOI: 10.1590/1519-6984.206124
    Xanthomonas oryzae pv. oryzae (Xoo), a pathogen responsible for rice bacterial leaf blight, produces biofilm to protect viable Xoo cells from antimicrobial agents. A study was conducted to determine the potency of Acacia mangium methanol (AMMH) leaf extract as a Xoo biofilm inhibitor. Four concentrations (3.13, 6.25, 9.38, and 12.5 mg/mL) of AMMH leaf extract were tested for their ability to inhibit Xoo biofilm formation on a 96-well microtiter plate. The results showed that the negative controls had the highest O.D. values from other treatments, indicating the intense formation of biofilm. This was followed by the positive control (Streptomycin sulfate, 0.2 mg/mL) and AMMH leaf extract at concentration 3.13 mg/mL, which showed no significant differences in their O.D. values (1.96 and 1.57, respectively). All other treatments at concentrations of 6.25, 9.38, and 12.5 mg/mL showed no significant differences in their O.D. values (0.91, 0.79, and 0.53, respectively). For inhibition percentages, treatment with concentration 12.5 mg/mL gave the highest result (81.25%) followed by treatment at concentrations 6.25 and 9.38 mg/mL that showed no significant differences in their inhibition percentage (67.75% and 72.23%, respectively). Concentration 3.13 mg/mL resulted in 44.49% of biofilm inhibition and the positive control resulted in 30.75% of biofilm inhibition. Confocal laser scanning microscopy (CLSM) analysis of Xoo biofilm inhibition and breakdown showed the presence of non-viable Xoo cells and changes in aggregation size due to increase in AMMH leaf extract concentration. Control slides showed the absence of Xoo dead cells.
  9. Fulltext Antifungal efficacy of Moringa oleifera leaf and seed extracts against Botrytis cinerea causing gray mold disease of tomato (Solanum lycopersicum L.)
    Ahmadu T, Ahmad K, Ismail SI, Rashed O, Asib N, Omar D
    Braz J Biol, 2020 11 12;81(4):1007-1022.
    PMID: 33175006 DOI: 10.1590/1519-6984.233173
    Drawbacks associated with the use of chemical fungicides to control plant pathogenic fungi such as Botrytis cinerea stimulate the need for alternatives. Therefore, the present study was carried out to determine the antifungal potentials of Moringa oleifera extracts against B. cinerea. Phytochemical analysis using qualitative chemical tests revealed the presence of huge amount of crucial phytochemicals compounds like phenolic compounds, alkaloids and saponins in the M. oleifera leaf extract. Antifungal bioassay of the crude extracts indicated better mycelial growth inhibition by methanol leaf extract (99%). The minimum inhibitory concentration (MIC) was 5 mg/ml with 100% spore germination inhibition and minimum fungicidal concentration (MFC) was 10 mg/ml with 98.10% mycelial growth inhibition using broth micro dilution and poisoned food techniques. Gas chromatography-mass spectrometry (GC-MS) analysis led to the identification of 67 volatile chemical compounds in the leaf extract with 6-decenoic acid (Z)- (19.87%) was the predominant compound. Further chemical elucidation of the crude extracts performed by liquid chromatography with tandem mass spectrometry (LC-MS/MS) showed the presence of non-volatile chemical compounds, mostly flavones, flavonoids and phenolic acids (i.e. quercetin and kaempferol). Scanning electron microscopy and transmission electron microscopy analysis showed positive effect of M. oleifera leaf extract on the treated conidia and mycelium of B. cinerea. Findings revealed that irreversible surface and ultra-structural changes with severe detrimental effects on conidia and mycelium morphology compared to control treatment. Overall findings suggested that M. oleifera leaf extract is a promising candidate for biological control of fungal pathogens, thus limiting overdependence on chemical fungicides.
  10. First Report of Paramyrothecium roridum causing leaf blight on water hyacinth (Eichhornia crassipes) in Malaysia
    Hassan IR, Omar D, Amit S, Ismail SI
    Plant Dis, 2021 Oct 05.
    PMID: 34609207 DOI: 10.1094/PDIS-04-21-0704-PDN
    Water hyacinth (Eichhornia crassipes) is a free-floating aquatic plant and is also widely cultivated as an aquatic ornamental plant in Malaysia. In June 2018, a severe foliar disease with typical leaf blight symptoms were observed on leaves of water hyacinth plants (approximately 50%) in waterways adjacent to two rice fields located at Tanjung Karang and Sungai Besar, Selangor province, Malaysia. Symptoms appeared irregular necrotic lesions with concentric rings, later lesions expanded to entire leaves and became blighted. Twenty symptomatic leaves were collected from two sampling locations. Symptomatic leaf tissue was cut into small pieces (5 × 5 mm), surface sterilized with 0.5% sodium hypochlorite (NaOCl) for 2 min, rinsed three times with sterile distilled water, plated on potato dextrose agar (PDA), and incubated at 25 °C with a 12-h light/dark cycle for 7 days. Twenty single-spore isolates were recovered from sampled leaves, all isolates exhibited Paramyrothecium-like morphology and two representative isolates, PR1 and PR2 were used for further studies. Fungal colonies were initially white aerial mycelia with sporodochia bearing olivaceous green conidial masses formed on PDA after 5 days of incubation. Conidiogenous cells were phialidic, hyaline, smooth, straight to slightly curved, 13 to 20 × 1.0 to 1.8 μm and setae were absent. Conidia were aseptate, hyaline to pale green, smooth, cylindrical to ellipsoidal with rounded ends, and measured 5.8 to 8.0 μm × 1.8 to 2.2 μm (n=50). These morphological characteristics were consistent with the description of Paramyrothecium roridum (Tode) L. Lombard & Crous (Lombard et al. 2016). Total genomic DNA of the isolates was extracted from fresh mycelium using DNeasy Plant Mini kit (Qiagen, USA). The internal transcribed spacer (ITS) and calmodulin (cmdA) gene regions were amplified using the ITS5/ITS4 (White et al.1990) and CAL-228F/CAL2Rd primer sets (Carbone and Kohn 1999; Groenewald et al., 2013), respectively. BLASTn analysis showed that the ITS and cmdA sequences of the isolates were 100% identity with Paramyrothecium roridum ex-epitype strain CBS 357.89 (GenBank accession nos. KU846300 and KU846270), respectively. The resulting sequences were deposited in GenBank (ITS: Accession nos. MW850370, MW850371; cmdA Accession nos. MW854363, MW854364). Pathogenicity tests of the two isolates were performed by spray inoculation on healthy leaves of each five potted water hyacinth plants using a 3-ml conidial suspension (1 × 106 conidia/ml) produced on 7-day-old PDA cultures incubated at 25 °C with a 12-h light/dark cycle. Five potted water hyacinth plants inoculated with sterile water served as controls. Inoculated plants were covered with plastic bags for 48 h to maintain high humidity and kept in a growth chamber for 2 weeks at 25 ± 1°C, 95% relative humidity and a 12-h light/dark period. The experiment was repeated twice. Eight days post-inoculation, symptoms on inoculated leaves developed necrotic brown lesions similar to those observed in the field, while control leaves remained asymptomatic. After 2 weeks of inoculation, lesions enlarged into severe blighting until all leaves died. Paramyrothecium roridum was re-isolated from randomly selected symptomatic tissues and verified by morphology and sequencing of ITS (MZ675387, MZ706462) and cmdA (MZ686706, MZ712041) loci, confirming Koch's postulates. The fungus was not re-isolated from non-inoculated control plants. Pa. roridum is distributed on a wide range of plants (Farr and Rossman 2021) and has been reported to cause leaf spot of water hyacinth in Nigeria (Okunowo et al. 2013) and Sri Lanka (Adikaram and Yakandawala 2020). To our knowledge, this is the first report of Pa. roridum causing leaf blight of water hyacinth in Malaysia. This disease is an emerging threat to water hyacinth and it reduces the leaf quality, therefore, appropriate management should be developed to control this disease.
  11. Fulltext First Report of Neoscytalidium dimidiatum Causing Fruit Rot on Guava (Psidium guajava L.) in Malaysia
    Ismail SI, Ahmad Dahlan K, Abdullah S, Zulperi D
    Plant Dis, 2020 Aug 04.
    PMID: 32748717 DOI: 10.1094/PDIS-06-20-1267-PDN
    Guava (Psidium guajava L.) is an economically important fruit crop in Malaysia with annual production of 67,087 tons in 2018 (FAO 2018). In February 2019, fruit rot symptoms were observed postharvest on approximately 30% of guava cv. Lohan collected from a commercial orchard in the Rawang district (3°23'22.8"N 101°26'55.7"E) of Selangor province, Malaysia. Symptoms on the fruits appeared as small, circular brown spots (ranging 5 to 20 mm in diameter) that coalesced and rapidly expanded to cover the entire fruit. Severely infected fruits became soft and rotted. Ten diseased guava fruits were collected from the sampling location. Small pieces (5x5x5 mm) of symptomatic fruit tissues were excised from the lesion margin, surface-sterilized with 0.5% sodium hypochlorite (NaOCl) for 1 min, rinsed twice with sterile distilled water, plated on potato dextrose agar (PDA) and incubated at 25 °C for 5 days. A Scytalidium-like fungus was consistently isolated from symptomatic tissues on PDA after 4 days. For morphological identification, single-spore cultures were grown on PDA at 25 °C and a representative isolate LB1 was characterized further. The fungal colonies were initially white, powdery, and later turned grayish-black with the onset of sporulation. The mycelia were branched with septa, pigmented, and brown in color. Fungal colonies produced dark-brown arthroconidia with thick-walled, 0 to 1-septa, averaged 9 μm x 5 μm (n=20), and cylindrical to oblong in shape. For molecular identification, genomic DNA was extracted from fresh mycelium of isolate LB1 using DNeasy Plant Mini kit (Qiagen, Germantown, MD, USA). The internal transcribed spacer (ITS) region of rDNA and translation elongation factor 1-alpha (TEF1-α) gene were amplified using ITS5/ITS4 (White et al. 1990) and EF1-728F/EF1-986R primer set (Carbone and Kohn 1999), respectively. Both ITS (954 bp) and TEF1-α (412 bp) sequences exhibited 100% identity to Neoscytalidium dimidiatum with GenBank accession numbers FM211432 and MK495414, respectively. The resulting sequences were deposited in GenBank (ITS: Accession no. MT565490; TEF1-α Accession no. MT572846). Based on the morphological and molecular data, the pathogen was identified as N. dimidiatum (Penz.) Crous & Slippers (Crous et al. 2006). A pathogenicity test was conducted on 5 healthy detached mature guava fruits cv. Lohan by wound-inoculating using a sterile needle and pipetting 10-µl of a conidial suspension (1 × 106 conidia/ml) of isolate LB1 to the wound. Five additional fruits were wounded and pipetted 10-µl sterile distilled water to serve as controls. Inoculated fruits were placed in sterilized plastic container and incubated at 25 ± 1 °C, 90% relative humidity with a photoperiod of 12 h, and the experiment was conducted twice. All inoculated fruits developed symptoms as described above 4 to 7 days post-inoculation, while the control fruits remained asymptomatic. N. dimidiatum was re-isolated from all symptomatic tissues confirming Koch's postulates. N. dimidiatum has been reported causing brown spot disease on pitaya (Lan et al. 2012), and stem canker on dragon fruit in Malaysia and Florida (Mohd et al. 2013; Sanahuja et al. 2016) but this is the first report of N. dimidiatum causing postharvest fruit rot on guava in Malaysia. This disease can cause significant postharvest losses to guava production which could lower marketable yield and proper control strategies should be implemented.
  12. Fulltext Current Classification of the Bacillus pumilus Group Species, the Rubber-Pathogenic Bacteria Causing Trunk Bulges Disease in Malaysia as Assessed by MLSA and Multi rep-PCR Approaches
    Husni AAA, Ismail SI, Jaafar NM, Zulperi D
    Plant Pathol J, 2021 Jun;37(3):243-257.
    PMID: 34111914 DOI: 10.5423/PPJ.OA.02.2021.0017
    Bacillus pumilus is the causal agent of trunk bulges disease affecting rubber and rubberwood quality and yield production. In this study, B. pumilus and other closely related species were included in B. pumilus group, as they shared over 99.5% similarity from 16S rRNA analysis. Multilocus sequence analysis (MLSA) of five housekeeping genes and repetitive elements-based polymerase chain reaction (rep-PCR) using REP, ERIC, and BOX primers conducted to analyze the diversity and systematic relationships of 20 isolates of B. pumilus group from four rubber tree plantations in Peninsular Malaysia (Serdang, Tanah Merah, Baling, and Rawang). Multi rep-PCR results revealed the genetic profiling among the B. pumilus group isolates, while MLSA results showed 98-100% similarity across the 20 isolates of B. pumilus group species. These 20 isolates, formerly established as B. pumilus, were found not to be grouped with B. pumilus. However, being distributed within distinctive groups of the B. pumilus group comprising of two clusters, A and B. Cluster A contained of 17 isolates close to B. altitudinis, whereas Cluster B consisted of three isolates attributed to B. safensis. This is the first MLSA and rep-PCR study on B. pumilus group, which provides an in-depth understanding of the diversity of these rubber-pathogenic isolates in Malaysia.
  13. Fulltext First Report of Nigrospora osmanthi Causing Leaf Blight on Orthosiphon stamineus in Malaysia
    Ismail SI, Mat Norzaki NA, Ya'acob ME, Jamian S
    Plant Dis, 2022 Jan 31.
    PMID: 34433313 DOI: 10.1094/PDIS-12-20-2668-PDN
  14. Ancestral state reconstruction infers phytopathogenic origins of sooty blotch and flyspeck fungi on apple
    Ismail SI, Batzer JC, Harrington TC, Crous PW, Lavrov DV, Li H, et al.
    Mycologia, 2016 Mar-Apr;108(2):292-302.
    PMID: 26740537 DOI: 10.3852/15-036
    Members of the sooty blotch and flyspeck (SBFS) complex are epiphytic fungi in the Ascomycota that cause economically damaging blemishes of apples worldwide. SBFS fungi are polyphyletic, but approx. 96% of SBFS species are in the Capnodiales. Evolutionary origins of SBFS fungi remain unclear, so we attempted to infer their origins by means of ancestral state reconstruction on a phylogenetic tree built utilizing genes for the nuc 28S rDNA (approx. 830 bp from near the 59 end) and the second largest subunit of RNA polymerase II (RPB2). The analyzed taxa included the well-known genera of SBFS as well as non-SBFS fungi from seven families within the Capnodiales. The non-SBFS taxa were selected based on their distinct ecological niches, including plant-parasitic and saprophytic species. The phylogenetic analyses revealed that most SBFS species in the Capnodiales are closely related to plant-parasitic fungi. Ancestral state reconstruction provided strong evidence that plant-parasitic fungi were the ancestors of the major SBFS lineages. Knowledge gained from this study may help to better understand the ecology and evolution of epiphytic fungi.
  15. Religious commitment, attitudes toward suicide, and suicidal behaviors among college students of different ethnic and religious groups in Malaysia
    Foo XY, Alwi MN, Ismail SI, Ibrahim N, Osman ZJ
    J Relig Health, 2014 Jun;53(3):731-46.
    PMID: 23196328 DOI: 10.1007/s10943-012-9667-9
    The variation in suicide patterns across ethnic groups with different religious background is a puzzling social phenomenon. This study sought to examine the impact of religious commitment and attitudes toward suicide on suicidal behaviors of college students across major ethnic and religious groups in a multicultural society of Malaysia. A total of 139 college students completed Religious Commitment Inventory-10, Attitudes Toward Suicide Scale, and Suicidal Behavior Questionnaire-Revised. Findings showed significant discrepancies in attitudes toward suicide, but not suicidal behaviors across ethnic and religious groups. Suicide acceptance significantly affected suicidal behaviors as well. Although religious commitment is not associated with suicidal behaviors, its deviation is reflected in students' acceptance of suicide. Additionally, college students' suicide risk, lifetime, and recent suicide ideation, as well as their likelihood of future suicide attempt can be associated with their acceptance of suicide. The influence of attitudes toward suicide and religion, therefore, should be taken into consideration while implementing suicide prevention programs as it helps shape the norms about suicide among youths.
  16. Fulltext Protocol of a Single-Blind Two-Arm (Waitlist Control) Parallel-Group Randomised Controlled Pilot Feasibility Study for mHealth App among Incontinent Pregnant Women
    Jaffar A, Mohd Sidik S, Foo CN, Muhammad NA, Abdul Manaf R, Fadhilah Ismail SI, et al.
    Int J Environ Res Public Health, 2021 04 30;18(9).
    PMID: 33946203 DOI: 10.3390/ijerph18094792
    BACKGROUND: The delivery of pelvic floor muscle training (PFMT) through mHealth apps has been shown to produce promising results in improving pelvic floor muscle strength and urinary incontinence (UI). However, there is limited evidence on mHealth apps designed for pregnant women who are at high risk of developing UI. This pilot study aims to evaluate the feasibility of conducting an effectiveness trial for a newly developed PFMT app among pregnant women in Malaysia.

    METHODS: This is a prospective, single-centre, single-blind, randomised controlled pilot feasibility study: The Kegel Exercise Pregnancy Training app (KEPT-app) Trial. Sixty-four incontinent pregnant women who attended one primary care clinic for the antenatal follow-up will be recruited and randomly assigned to either intervention or waitlist control group. The intervention group will receive the intervention, the KEPT-app developed from the Capability, Opportunity, Motivation-Behaviour (COM-B) theory with Persuasive Technology and Technology Acceptance Model.

    DISCUSSION: This study will provide a fine-tuning for our future randomised control study on the recruitment feasibility methods, acceptability, feasibility, and usability of the KEPT-app, and the methods to reduce the retention rates among pregnant women with UI.

    TRIAL REGISTRATION: This study was registered on ClinicalTrials.gov on 19 February 2021 (NCT04762433) and is not yet recruiting.

  17. Asp-376-Glu substitution endows target-site resistance to AHAS inhibitors in Limnocharis flava, an invasive weed in tropical rice fields
    Zakaria N, Ruzmi R, Moosa S, Asib N, Zulperi D, Ismail SI, et al.
    Physiol Mol Biol Plants, 2021 May;27(5):969-983.
    PMID: 34108823 DOI: 10.1007/s12298-021-00987-3
    Limnocharis flava (L.) Buchenau is a problematic weed in rice fields and water canals of Southeast Asia, and in Malaysia this invasive aquatic weed species has evolved multiple resistance to synthetic auxin herbicide and acetohydroxyacid synthase (AHAS) inhibitors. In this study, it was revealed that, a single nucleotide polymorphism (SNP) at amino acid position 376, where C was substituted to G at the third base of the same codon (GAC to GAG), resulting in Aspartate (Asp) substitution by Glutamate (Glu) was the contributing resistance mechanism in the L. flava population to AHAS inhibitors. In vitro assay further proved that, all the L. flava individuals carrying AHAS resistance mutation exhibited decreased-sensitivity to AHAS inhibitors at the enzyme level. In the bensulfuron-methyl whole-plant bioassay, high resistance indices (RI) of 328- and 437-fold were recorded in the absence and presence of malathion (the P450 inhibitor), respectively. Similarly, translocation and absorption of bensulfuron-methyl in both resistant and susceptible L. flava populations showed no remarkable differences, hence eliminated the possible co-existence of non-target-site resistance mechanism in the resistant L. flava. This study has confirmed another new case of a target-site resistant weed species to AHAS-inhibitors.
  18. Fulltext Phytopathogenic organisms and mycotoxigenic fungi: Why do we control one and neglect the other? A biological control perspective in Malaysia
    Yazid SNE, Jinap S, Ismail SI, Magan N, Samsudin NIP
    Compr Rev Food Sci Food Saf, 2020 03;19(2):643-669.
    PMID: 33325175 DOI: 10.1111/1541-4337.12541
    In this review, we present the current information on development and applications of biological control against phytopathogenic organisms as well as mycotoxigenic fungi in Malaysia as part of the integrated pest management (IPM) programs in a collective effort to achieve food security. Although the biological control of phytopathogenic organisms of economically important crops is well established and widely practiced in Malaysia with considerable success, the same cannot be said for mycotoxigenic fungi. This is surprising because the year round hot and humid Malaysian tropical climate is very conducive for the colonization of mycotoxigenic fungi and the potential contamination with mycotoxins. This suggests that less focus has been made on the control of mycotoxigenic species in the genera Aspergillus, Fusarium, and Penicillium in Malaysia, despite the food security and health implications of exposure to the mycotoxins produced by these species. At present, there is limited research in Malaysia related to biological control of the key mycotoxins, especially aflatoxins, Fusarium-related mycotoxins, and ochratoxin A, in key food and feed chains. The expected threats of climate change, its impacts on both plant physiology and the proliferation of mycotoxigenic fungi, and the contamination of food and feed commodities with mycotoxins, including the discovery of masked mycotoxins, will pose significant new global challenges that will impact on mycotoxin management strategies in food and feed crops worldwide. Future research, especially in Malaysia, should urgently focus on these challenges to develop IPM strategies that include biological control for minimizing mycotoxins in economically important food and feed chains for the benefit of ensuring food safety and food security under climate change scenarios.
  19. Genetic diversity analysis of selected Capsicum annuum genotypes based on morphophysiological, yield characteristics and their biochemical properties
    Ridzuan R, Rafii MY, Mohammad Yusoff M, Ismail SI, Miah G, Usman M
    J Sci Food Agric, 2019 Jan 15;99(1):269-280.
    PMID: 29851100 DOI: 10.1002/jsfa.9169
    BACKGROUND: Assessment of the different desirable characters among chili genotypes has expanded the effective selection for crop improvement. Identification of genetically superior parents is important in assortment of the best parents to develop new chili hybrids.

    RESULTS: This study was done to assess the hereditary assorted variety of selected genotypes of Capsicum annuum based on their morphophysiological and yield traits in two planting seasons. The biochemical properties, capsaicinoid content (capsaicin and dihydrocapsaicin), total phenolics content and antioxidant action determination of unripe and ripe chili pepper fruits were carried out in dry fruits. AVPP9813 and Kulai 907 were observed to have high fruit yields, with 541.39 and 502.64 g per plant, respectively. The most increased genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) were shown by the fruit number per plant (49.71% and 66.04%, respectively). High heritability was observed in yield characters viz-à-viz fruit weight, length and girth and indicated high genetic advance. Eight groups were obtained from the cluster analysis. For the biochemical analysis, the capsaicinoid content and total phenolic content were high in Chili Bangi 3 at unripe and ripe fruit stages, while for antioxidant activity SDP203 was the highest in ripe dry fruit.

    CONCLUSION: Higher GCV and PCV, combined with moderate to high heritability and high hereditary progress, were seen in number of fruit per plant, fruit yield per plant and fruit weight per fruit. These findings are beneficial for chili pepper breeders to select desirable quantitative characters in C. annuum in their breeding program. © 2018 Society of Chemical Industry.

  20. Fulltext Breeding for Anthracnose Disease Resistance in Chili: Progress and Prospects
    Ridzuan R, Rafii MY, Ismail SI, Mohammad Yusoff M, Miah G, Usman M
    Int J Mol Sci, 2018 Oct 11;19(10).
    PMID: 30314374 DOI: 10.3390/ijms19103122
    Chili anthracnose is one of the most devastating fungal diseases affecting the quality and yield production of chili. The aim of this review is to summarize the current knowledge concerning the chili anthracnose disease, as well as to explore the use of marker-assisted breeding programs aimed at improving anthracnose disease resistance in this species. This disease is caused by the Colletotrichum species complex, and there have been ongoing screening methods of chili pepper genotypes with resistance to anthracnose in the field, as well as in laboratories. Conventional breeding involves phenotypic selection in the field, and it is more time-consuming compared to molecular breeding. The use of marker-assisted selection (MAS) on the basis of inheritance, the segregation ratio of resistance to susceptibility, and the gene-controlling resistance may contribute to the development of an improved chili variety and speed up the selection process, while also reducing genetic drag in the segregating population. More importantly, by using molecular markers, the linkage groups are determined dominantly and co-dominantly, meaning that the implementation of a reliable method to produce resistant varieties is crucial in future breeding programs. This updated information will offer a supportive direction for chili breeders to develop an anthracnose-resistant chili variety.
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