Displaying publications 1 - 20 of 43 in total

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  1. Yashni G, Al-Gheethi A, Radin Mohamed RMS, Dai-Viet NV, Al-Kahtani AA, Al-Sahari M, et al.
    Chemosphere, 2021 Oct;281:130661.
    PMID: 34029959 DOI: 10.1016/j.chemosphere.2021.130661
    Textile industry is one of the most environmental unfriendly industrial processes due to the massive generation of colored wastewater contaminated with dyes and other chemical auxiliaries. These contaminants are known to have undesirable consequences to ecosystem. The present study investigated the best operating parameters for the removal of congo red (CR, as the model for dye wastewater) by orange peels extract biosynthesized zinc oxide nanoparticles (ZnO NPs) via photocatalysis in an aqueous solution. The response surface methodology (RSM) with ZnO NPs loadings (0.05-0.20 g), pH (3.00-11.00), and initial CR concentration (5-20 ppm) were used for the optimization process. The applicability of ZnO NPs in the dye wastewater treatment was evaluated based on the techno-economic analysis (TEA). ZnO NPs exhibited hexagonal wurtzite structure with = C-H, C-O, -C-O-C, CC, O-H as the main functional groups. The maximum degradation of CR was more than 96% with 0.171 g of ZnO NPs, at pH 6.43 and 5 ppm of CR and 90% of the R2 coefficient. The specific cost of ZnO NPs production is USD 20.25 per kg. These findings indicated that the biosynthesized ZnO NPs with orange peels extract provides alternative method for treating dye wastewater.
    Matched MeSH terms: Citrus sinensis*
  2. Phing PL, Abdullah A, Sin CL, Foong SCY
    Acta Sci Pol Technol Aliment, 2022 2 18;21(1):111-122.
    PMID: 35174693 DOI: 10.17306/J.AFS.0901
    BACKGROUND: Bintangor oranges are a mandarin species that is abundant in vitamin C and beta-carotene. However, due to its short shelf life, the fresh fruit can be converted into powder form, which is comparatively more stable.

    METHODS: This study compares the effects of spray drying, freeze drying, drum drying, vacuum oven drying, and convection oven drying on the physicochemical properties of Bintangor orange powder, including vitamin C and total carotenoid content. The physicochemical properties analyzed for the powders were color analysis, moisture content, water activity, hygroscopicity, degree of caking, wettability, flowability, water solubility index, and bulk density.

    RESULTS: Our results showed that freeze dried and convection oven dried powders retained their color so that the powder was the same as the original puree. All powders used in this showed an acceptable moisture content level, with a range of 2.11–2.31%. Spray dried and drum dried powders had the lowest value of moisture content and water activity. Moreover, spray dried powders showed the lowest value in hygroscopicity and bulk density and took the shortest time to wet the powder. The highest solubility and flowability properties were 12.99%, 0.39 g/mL, 18.39 s, 96.08%, and 19.17°, respectively. However, the freeze drying method retained the highest value for both nutritional pigments of vitamin C and total carotenoid content, 18.31 mg/g and 91.32 μg/g, respectively.

    CONCLUSIONS: Freeze drying is the most suitable drying method with favorable powder properties compared to spray drying, drum drying, vacuum oven drying and convection oven drying.

    Matched MeSH terms: Citrus sinensis*
  3. Kwon D, Oh JI, Lam SS, Moon DH, Kwon EE
    Bioresour Technol, 2019 Aug;285:121356.
    PMID: 31005642 DOI: 10.1016/j.biortech.2019.121356
    To valorize biomass waste, pyrolysis of orange peel was mainly investigated as a case study. In an effort to establish a more sustainable thermolytic platform for orange peel, this study particularly employed CO2 as reactive gas medium. Accordingly, this study laid great emphasis on elucidating the mechanistic role of CO2 in pyrolysis of orange peel. The thermo-gravimetric analysis (TGA) confirmed that no occurrence of the heterogeneous reactions between the solid sample and CO2. However, the gaseous effluents from pyrolysis of orange peel experimentally proved that CO2 effectively suppressed dehydrogenation of volatile matters (VMs) evolved from the thermolysis of orange peel by random bond scissions. Moreover, CO2 reacted VMs, thereby resulting in the formation of CO. Note that the formation of CO was being initiated at temperatures ≥550 °C. The two identified roles of CO2 led to the compositional modification of pyrolytic oil by means of lowering aromaticity.
    Matched MeSH terms: Citrus sinensis
  4. See MS, Musa N, Liew HJ, Harun NO, Rahmah S
    J Environ Manage, 2024 Feb;351:119677.
    PMID: 38042084 DOI: 10.1016/j.jenvman.2023.119677
    Sweet orange Citrus sinensis peel is a phytobiotic agricultural waste with bioactive compounds that have potential functional properties as a growth promoter and immune stimulator. This study aims to evaluate the dietary effects of sweet orange peel (SOP) as a feed additive on growth enhancement of juvenile bagrid catfish Mystus nemurus and their disease resistance ability against Aeromonas hydrophila infection. Four experimental diets were formulated to contain 0 (SOP0, control), 4 (SOP4), 8 (SOP8) and 12 g/kg (SOP12) SOP. After 90 d of the feeding experiment, improvement in weight gain, specific growth rate, feed conversion ratio, and protein efficiency ratio were observed in the fish fed with SOP4. While fish survival was not significantly affected, hepatosomatic and viscerosomatic indices were significantly higher in fish fed with SOP12. Muscle protein was higher in fish fed with SOP4, SOP8, and SOP12 than in control but muscle lipids showed an opposite trend. A 14-d post-challenge test against A. hydrophila revealed no significant effect on the fish survival. Nevertheless, fish fed SOP4 encountered delayed bacterial infection compared to other treatments and fish fed with SOP0 and SOP4 performed numerically better survival. Infected fish showed skin depigmentation, haemorrhagic signs at the abdomen and anus, internal bleeding, and stomach and intestine enlargement. In conclusion, SOP4 could be recommended as a growth promoter while slightly delaying A. hydrophila infection in M. nemurus.
    Matched MeSH terms: Citrus sinensis*
  5. Normah, Ismail, Ezzana Zuraini, Zainuddin
    Scientific Research Journal, 2015;12(1):1-12.
    MyJurnal
    Proteases were extracted from starfruit at maturity Index 2 (unripe, light green) and Index 7 (very ripe, orange) and partially purified using acetone and 40% ammonium sulfate precipitations. Higher yield and proteolytic activity were observed for proteases purified using acetone than 40% ammonium sulfate. As for maturity index, yield and protein concentration of proteases from Index 2 were higher than those from Index 7. SDS-PAGE result showed intense bands for acetone proteases while a distinct band at 50 kDa was observed in all the proteases. Enzyme activity decreased during the seven days storage at 4°C with minimum relative activity of 70% achieved for acetone proteases at day seven. This study suggested that acetone precipitation is more effective method for purifying starfruit protease based on the yield and proteolytic activity compared to using 40% ammonium sulphate precipitation. In order to obtain higher protein concentration and proteolytic activity, starfruit at the unripe stage, Index 2 is a better raw material than Index 7 to be used for protease production.
    Matched MeSH terms: Citrus sinensis
  6. Kamal, G.M., Anwar, F., Hussain, A.I., Sarri, N., Ashraf, M.Y.
    MyJurnal
    Citrus peel essential oils have an impressive range of food and medicinal uses. In the present study we investigated the variation in the yield and chemical composition of the essential oils isolated from fresh, ambient-, and oven-dried peels of three Citrus species namely Citrus reticulata (C. reticulata), Citrus sinensis (C. sinensis) and Citrus paradisii (C. paradisii). The hydro-distilled essential oil content from fresh-, ambient-, and oven-dried peels of C. reticulata, C. sinensis and C. paradisii ranged from 0.30-0.50, 0.24-1.07 and 0.20-0.40 g/100 g, respectively. The maximum amount of the oil was determined in oven-dried while the minimum in fresh peel samples. Using GC and GC/MS, a total of 16-27, 17-24 and 18-40 chemical constituents were identified in the peel essential oils of C. reticulate, C. sinensis and C. paradisii, respectively. The content of limonene, the most prevalent chemical constituent, detected in these essential oils, ranged from 64.1-71.1% (C. reticulata), 66.8-80.9% (C. sinensis) and 50.8-65.5% (C. paradisii). The yield and content of most of the chemical components including limonene (the principal chemical compound detected) of the tested essential oils varied significantly (p < 0.05) with respect to drying treatments and species employed.
    Matched MeSH terms: Citrus sinensis
  7. Foo KY, Hameed BH
    Bioresour Technol, 2012 Jan;104:679-86.
    PMID: 22101073 DOI: 10.1016/j.biortech.2011.10.005
    This work explores the feasibility of orange peel, a citrus processing biomass as an alternative precursor for preparation of activated carbon (OPAC) via microwave assisted K(2)CO(3) activation. The operational parameters, chemical impregnation ratio, microwave power and irradiation time on the carbon yield and adsorption capability were investigated. The virgin characteristics of OPAC were examined by pore structural analysis, scanning electron microscopy, Fourier transform infrared spectroscopy, nitrogen adsorption isotherm, elemental analysis, surface acidity/basicity and zeta potential measurement. The optimum conditions resulted in OPAC with a monolayer adsorption capacity of 382.75 mg/g for methylene blue and carbon yield of 80.99%. The BET surface area, Langmuir surface area and total pore volume were identified to be 1104.45 m(2)/g, 1661.04 m(2)/g and 0.615 m(3)/g, respectively. Equilibrium data were simulated using the Langmuir, Freundlich, Dubinin-Radushkevich, Redlich-Peterson, and Toth isotherms, and kinetic data were fitted to the pseudo-first-order, pseudo-second-order and Elovich kinetic models.
    Matched MeSH terms: Citrus sinensis/radiation effects*; Citrus sinensis/chemistry*
  8. Zhan SZ, Li M, Zheng J, Wang QJ, Ng SW, Li D
    Inorg Chem, 2017 Nov 06;56(21):13446-13455.
    PMID: 29023107 DOI: 10.1021/acs.inorgchem.7b02144
    Six daughter complexes based on two-dimensional (2-D) luminescent Cu4I4-Cu3Pz3(Pz = pyrazolate) coordination networks, which exhibit an uncommon Cu4I4L3L' (L = pyridine; L' = acetonitrile, pyridine, pyrazine, 1,4-diazabicyclo[2.2.2]octane, triphenylphosphine, none) local configuration, were prepared through a postsynthetic modification method starting from a parent complex (L' = NH3). This work has successfully implemented the single-site substitution of Cu4I4-based coordination frameworks, which have rarely been reported for isolated Cu4I4-type compounds, by taking advantage of the solvent-assisted ligand substitution strategy recently developed in metal-organic framework (MOF) chemistry. Such a procedure not only resulted in the variation of local geometry in the Cu4I4units but also led to interlayer network displacement and entanglement. Particularly, an interesting topological transformation (from 2-D to 2-D → 3-D interpenetration) occurred when linear bidentate linkers (e.g., pyrazine and 1,4-diazabicyclo[2.2.2]octane) are inserted between the 2-D layers. Moreover, the variation in the L' sites can effectively tune the emission colors, ranging from green to orange (λemmax540-605 nm at room temperature). The photoluminescence origins are tentatively assigned to be a mixture of3MLCT and3XLCT, different from that of the well-studied isolated Cu4I4-type complexes.
    Matched MeSH terms: Citrus sinensis
  9. Vinoth S, Subramani K, Ong WJ, Sathish M, Pandikumar A
    J Colloid Interface Sci, 2021 Feb 15;584:204-215.
    PMID: 33069019 DOI: 10.1016/j.jcis.2020.09.071
    This work demonstrates a high-performance hybrid asymmetric supercapacitor (HASC) workable in very high current density of 30 A g-1 with in-situ pyrolytic processed sulfur-doped graphitic carbon nitride/cobalt disulfide (S-gC3N4/CoS2) materials and bio-derived carbon configuration and achievement of high electrochemical stability of 89% over 100,000 cycles with the coulombic efficiency of 99.6%. In the electrochemical studies, the S-gC3N4/CoS2-II electrode showed a high specific capacity of 180 C g-1 at 1 A g-1 current density in the half-cell configuration. The HASC cell was fabricated using S-gC3N4/CoS2-II material and orange peel derived activated carbon as a positive and negative electrode with a maximum operating cell potential of 1.6 V, respectively. The fabricated HASC delivered a high energy density of 26.7 Wh kg-1 and power density of 19.8 kW kg-1 in aqueous electrolyte. The prominent properties in specific capacity and cycling stability could be attributed to the CoS2 nanoparticles engulfed into the S-gC3N4 framework which provides short transport distance of the ions, strong interfacial interaction, and improving structural stability of the S-gC3N4/CoS2-II materials.
    Matched MeSH terms: Citrus sinensis
  10. Balke M, Bergsten J, Wang LJ, Hendrich L
    Zookeys, 2017.
    PMID: 28325968 DOI: 10.3897/zookeys.647.11231
    Rompindessus jenisi Balke, Bergsten & Hendrich, gen. n. et sp. n. is described from near Rompin village in West Malaysia. The new genus is characterized by the presence of an occipital line and basal pronotal striae, the presence of a thick anterior bead on clypeus and two-segmented parameres as well as by the absence of basal elytral striae, the absence of sutural line on elytron, the absence of basal epipleural transverse carina, and the absence of longitudinal elytral carina. Moreover, male pro- and mesotarsus appear stout, and distinctly dilated laterally; the pronotum is comparably long and parallel-sided and the colour of beetle conspicuous dark orange. Leiodytes kualalipis Balke, Wang, Bergsten & Hendrich, sp. n. is described from West Malaysia (Pahang) and South Vietnam (Cat Tien). It is well characterized by its large size, elongate body and the form of the median lobe. Limbodessus fijiensis (J. Balfour-Browne, 1944), comb. n. described from Fiji is a new synonym of Limbodessus curviplicatus (Zimmermann, 1927) described from Samoa.
    Matched MeSH terms: Citrus sinensis
  11. Norshazila, S., Irwandi, J., Othman, R., Yumi Zuhanis, H.H.
    MyJurnal
    Characterization and quantification of carotenoid compound is complicated, costly and timeconsuming. The accuracy and reliability of the data depend solely on the standard and to High Performance Liquid Chromatography (HPLC) analysis but the major constraint is to acquire and to maintain the pure standards. Carotenoid standards are commercially available but they are expensive and are prone to isomerization and oxidation. Thus, the purpose of this study is to establish an analytical method for isolating β-carotene by using open column chromatography (OCC) from pumpkin (Cucurbita moschata) to be used as one of the carotenoid standards for determination of total and individual carotenoid. Pumpkin with orange flesh has been chosen due to the non-seasonal nature and its availability all year-round. This study demonstrated that the purity of β-carotene standard; determined by HPLC was ranged from 92.21 to 97.95%. The standard curves with five different concentrations of β-carotene extract from pumpkins in triplicate were constructed by plotting the peak area against the concentration. The coefficient of correlation was 0.9936. Therefore, this study established that pumpkin can be a reliable source of beta-carotene standard as it is cheap and commonly available throughout the year.
    Matched MeSH terms: Citrus sinensis
  12. Ismail, I., Anuar, M. S., Shamsudin, R.
    MyJurnal
    Liberica coffee is the most important coffee species grown in Malaysia. However, there is little or no research at all conducted on coffee berries and green coffee beans since the plant itself is a low income crop in Malaysia. Therefore, research on Malaysian Liberica coffee can help to increase the knowledge of coffee farmers and coffee manufacturers in the processing and handling of the coffee. Physical properties of Liberica coffee berries and beans were investigated the current study. The properties investigated include the size, mass, density, coefficient of friction, angle of repose, fracture force and colour. In comparison to Arabica and Robusta coffee, Liberica coffee has the biggest size, mass, true density and fracture force values but were lower in bulk density in both berries and beans. The Liberica berries and beans were found to be orange-ish and yellowish colour respectively. Angle of repose was low and approximately similar in berries and beans while jute fibre gave the highest friction to both Liberica berries and beans.
    Matched MeSH terms: Citrus sinensis
  13. Mirhosseini H, Tan CP, Yusof S, Hamid NS
    Phytochem Anal, 2008 Sep-Oct;19(5):429-37.
    PMID: 18435528 DOI: 10.1002/pca.1068
    Solid-phase microextraction (SPME) coupled to gas chromatography has been applied for the headspace analysis (HS) of 12 target flavour compounds in a model orange beverage emulsion. The main volatile flavour compounds studied were: acetaldehyde, ethyl acetate, alpha-pinene, ethyl butyrate, beta-pinene, myrcene, limonene, gamma-terpinene, octanal, decanal, linalool and citral (neral plus geranial). After screening the fibre type, the effect of other HS-SPME variables such as adsorption temperature (25-55 degrees C), extraction time (10-40 min), sample concentration (1-100% w/w), sample amount (5-10 g) and salt amount (0-30% w/w) were determined using a two-level fractional factorial design (2(5-2)) that was expanded further to a central composite design. It was found that an extraction process using a carboxen-polydimethylsiloxane fibre coating at 15 masculineC for 50 min with 5 g of diluted emulsion 1% (w/w) and 30% (w/w) of sodium chloride under stirring mode resulted in the highest HS extraction efficiency. For all volatile flavour compounds, the linearity values were accurate in the concentration ranges studied (r(2) > 0.97). Average recoveries that ranged from 90.3 to 124.8% showed a good accuracy for the optimised method. The relative standard deviation for six replicates of all volatile flavour compounds was found to be less than 15%. For all volatile flavour compounds, the limit of detection ranged from 0.20 to 1.69 mg/L.
    Matched MeSH terms: Citrus sinensis*
  14. Mirhosseini H, Tan CP
    J Sci Food Agric, 2010 Jun;90(8):1308-16.
    PMID: 20474048 DOI: 10.1002/jsfa.3928
    The constituents in a food emulsion interact with each other, either physically or chemically, determining the overall physico-chemical and organoleptic properties of the final product. Thus, the main objective of present study was to investigate the effect of emulsion components on beverage emulsion properties.
    Matched MeSH terms: Citrus sinensis*
  15. Norsyuhada W, Shukri WM, Bidin N, Islam S, Krishnan G
    J Nanosci Nanotechnol, 2018 Jul 01;18(7):4841-4851.
    PMID: 29442664 DOI: 10.1166/jnn.2018.15358
    Au-Ag alloy nanoparticles are physically synthesized using rapid, simple and efficient Q-switched Nd:YAG pulsed laser ablation in liquid technique (PLAL). Au and Ag colloidal solutions are separately prepared by 1064 nm laser ablation of metallic target (gold and silver) which is immersed in deionized water. Au-Ag alloy nanoparticles are prepared by irradiating the mixture of Au and Ag colloidal solutions with 532 nm of second harmonic wavelength of Nd:YAG laser at three different ratio, 3:1, 1:1 and 1:3 within different exposure times. The three of plasmon absorption bands of Au-Ag nanoparticles are shifted linearly to the lower wavelength [499.67 nm (3:1), 481.25 nm (1:1), 467.91 nm (1:3)], as compared to plasmon absorption spectra of pure Au (520 nm) and Ag (400 nm). Moreover, the change in colors are also observed from red (Au) and yellow (Ag) to orange, brown and green color due to the Au-Ag alloy formations, respectively. Transmission electron microscopy shows the Ag shell around the inner core of Au spherical metal with broad size distribution due to the three different volume ratio, respectively (1.7 nm, 0.7 nm, 1.4 nm). Energy-dispersive X-ray spectroscopy analysis confirms the presence of Au and Ag elements in Au-Ag alloy nanoparticles without any contaminations. Attenuated total reflectance fourier transform infrared spectroscopy analysis also confirms the homogenous Au-Ag alloys chemical bonding.
    Matched MeSH terms: Citrus sinensis
  16. Goulding TC, Khalil M, Tan SH, Dayrat B
    Zookeys, 2018.
    PMID: 29896045 DOI: 10.3897/zookeys.763.21252
    A new genus of onchidiid slugs, Wallaconchis Goulding & Dayrat, gen. n., is described, including ten species. Five species were previously described but known only from the type material: Wallaconchis ater (Lesson, 1830), W. graniferum (Semper, 1880), W. nangkauriense (Plate, 1893), W. buetschlii (Stantschinsky, 1907), and W. gracile (Stantschinsky, 1907), all of which were originally classified in Onchidium Buchannan, 1800. Many new records are provided for these five species, which greatly expand their known geographic distributions. Five species are new: Wallaconchis achleitneri Goulding, sp. n., W. comendadori Goulding & Dayrat, sp. n., W. melanesiensis Goulding & Dayrat, sp. n., W. sinanui Goulding & Dayrat, sp. n., and W. uncinus Goulding & Dayrat, sp. n. Nine of the ten Wallaconchis species are found in the Coral Triangle (eastern Indonesia and the Philippines). Sympatry is high, with up to six species found on the island of Bohol (Philippines) and eight species overlapping in northern Sulawesi (Indonesia). Wallaconchis is distinguished from other onchidiids by its bright dorsal colors (red, yellow, orange) but those are extremely variable and not useful for specific identification. Internally, the reproductive system can be used to identify all Wallaconchis species. The copulatory organs of Wallaconchis species are especially diverse compared to other onchidiid genera, and the possible role of reproductive incompatibility in species diversification is discussed. All specimens examined were freshly collected for the purpose of a worldwide revision of the Onchidiidae Rafinesque, 1815. The species are well delineated using DNA sequences and comparative anatomy. Mitochondrial DNA analysis yields thirteen molecular units separated by a large barcode gap, while nuclear DNA yields nine units. By integrating nuclear DNA and mitochondrial DNA with morphology, ten species are recognized. The natural history of each species (e.g., the microhabitat where they are found) is also documented. Nomenclature is addressed thoroughly (the types of all onchidiid species were examined, lectotypes were designated when needed, nomina dubia are discussed). Morphological characters, transitions to new microhabitats, and diversification processes are discussed in the context of a robust molecular phylogeny.
    Matched MeSH terms: Citrus sinensis
  17. Panettieri S, Gjinaj E, John G, Lohman DJ
    PLoS One, 2018;13(9):e0202465.
    PMID: 30208047 DOI: 10.1371/journal.pone.0202465
    With varied, brightly patterned wings, butterflies have been the focus of much work on the evolution and development of phenotypic novelty. However, the chemical structures of wing pigments from few butterfly species have been identified. We characterized the orange wing pigments of female Elymnias hypermnestra butterflies (Lepidoptera: Nymphalidae: Satyrinae) from two Southeast Asian populations. This species is a sexually dimorphic Batesian mimic of several model species. Females are polymorphic: in some populations, females are dark, resemble conspecific males, and mimic Euploea spp. In other populations, females differ from males and mimic orange Danaus spp. Using LC-MS/MS, we identified nine ommochrome pigments: six from a population in Chiang Mai, Thailand, and five compounds from a population in Bali, Indonesia. Two ommochromes were found in both populations, and only two of the nine compounds have been previously reported. The sexually dimorphic Thai and Balinese populations are separated spatially by monomorphic populations in peninsular Malaysia, Singapore, and Sumatra, suggesting independent evolution of mimetic female wing pigments in these disjunct populations. These results indicate that other butterfly wing pigments remain to be discovered.
    Matched MeSH terms: Citrus sinensis
  18. Mawlud SQ
    PMID: 30359852 DOI: 10.1016/j.saa.2018.10.032
    Enhanced red and orange fluorescence emissions of Sm3+ Rare earth (RE) ions were observed in sodium‑zinc tellurite glasses embedded with silver and gold nanoparticles (NPs). The fine distribution of NPs in the glass matrix with an average diameter ~ 11.09 nm and ~3.86 nm for Ag and Au NPs respectively were confirmed by using transmission electron microscope (TEM). The embedding of Ag and Au NPs into the glass structure caused an increasing in the transition emission intensity of Sm3+ ions, which is ascribed to the progress of the presence of the localized surface Plasmon resonance (LSPR) indicating from the characteristic absorption peaks. The luminescence and absorption spectra have been discussed using a standard hypothesis Judd-Ofelt theory for a certain absorption transitions 6P3/2, 4I11/2, 6F11/2, 6F9/2, 6F7/2, 6F5/2, 6F3/2, 6H15/2, 6F1/2 and emission transitions 6H5/2, H7/2, 6H9/2 and H11/2 under 409 nm excitation of the Sm3+ ions. The decay life time curve exhibited a non-exponential behavior of the studied glass samples and the results were compared with the similar reported glasses. An efficient red and orange fluorescence emission illustrate that the Sm3+-doped sodium‑zinc tellurite embedded with Ag and Au NPs are potential materials for the laser illumination.
    Matched MeSH terms: Citrus sinensis
  19. Nasehi A, Kadir JB, Abidin MAZ, Wong MY, Ashtiani FA
    Plant Dis, 2012 Aug;96(8):1227.
    PMID: 30727084 DOI: 10.1094/PDIS-03-12-0262-PDN
    Symptoms of gray leaf spot were first observed in June 2011 on pepper (Capsicum annuum) plants cultivated in the Cameron Highlands and Johor State, the two main regions of pepper production in Malaysia (about 1,000 ha). Disease incidence exceeded 70% in severely infected fields and greenhouses. Symptoms initially appeared as tiny (average 1.3 mm in diameter), round, orange-brown spots on the leaves, with the center of each spot turning gray to white as the disease developed, and the margin of each spot remaining dark brown. A fungus was isolated consistently from the lesions using sections of symptomatic leaf tissue surface-sterilized in 1% NaOCl for 2 min, rinsed in sterile water, dried, and plated onto PDA and V8 agar media (3). After 7 days, the fungal colonies were gray, dematiaceous conidia had formed at the end of long conidiophores (19.2 to 33.6 × 12.0 to 21.6 μm), and the conidia typically had two to six transverse and one to four longitudinal septa. Fifteen isolates were identified as Stemphylium solani on the basis of morphological criteria described by Kim et al. (3). The universal primers ITS5 and ITS4 were used to amplify the internal transcribed spacer region (ITS1, 5.8, and ITS2) of ribosomal DNA (rDNA) of a representative isolate (2). A 570 bp fragment was amplified, purified, sequenced, and identified as S. solani using a BLAST search with 100% identity to the published ITS sequence of an S. solani isolate in GenBank (1). The sequence was deposited in GenBank (Accession No. JQ736024). Pathogenicity of the fungal isolate was tested by inoculating healthy pepper leaves of cv. 152177-A. A 20-μl drop of conidial suspension (105 spores/ml) was used to inoculate each of four detached, 45-day-old pepper leaves placed on moist filter papers in petri dishes (4). Four control leaves were inoculated similarly with sterilized, distilled water. The leaves were incubated at 25°C at 95% relative humidity for 7 days. Gray leaf spot symptoms similar to those observed on the original pepper plants began to develop on leaves inoculated with the fungus after 3 days, and S. solani was consistently reisolated from the leaves. Control leaves did not develop symptoms and the fungus was not reisolated from these leaves. Pathogenicity testing was repeated with the same results. To our knowledge, this is the first report of S. solani causing gray leaf spot on pepper in Malaysia. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997. (2) M. P. S. Camara et al. Mycologia 94:660, 2002. (3) B. S. Kim et al. Plant Pathol. J. 15:348, 1999. (4) B. M. Pryor and T. J. Michailides. Phytopathology 92:406, 2002.
    Matched MeSH terms: Citrus sinensis
  20. Intan Sakinah MA, Suzianti IV, Latiffah Z
    Plant Dis, 2013 Jul;97(7):991.
    PMID: 30722542 DOI: 10.1094/PDIS-10-12-0985-PDN
    Banana is the second largest cultivated fruit crop in Malaysia, and is cultivated for both the domestic market and also for export. Anthranose is a well-known postharvest disease of banana and with high potential for damaging market value, as infection commonly occurs during storage. Anthracnose symptoms were observed on several varieties of banana such as mas, berangan, awak, nangka, and rastali in the states of Perak and Penang between August and October 2011. Approximately 80% of the fruits became infected with initial symptoms characterized as brown to black spots that later became sunken lesions with orange or salmon-colored conidial masses. Infected tissues (5 × 5 mm) were surface sterilized by dipping in 1% sodium hypochlorite (NaOCl) for 3 to 5 min, rinsed with sterile distilled water, and plated onto potato dextrose agar (PDA). Direct isolation was done by transferring the conidia from conidial masses using an inoculation loop and plating onto PDA. For both methods, the PDA plates were incubated at 27 ± 1°C with cycles of 12 h light and 12 h darkness. Visible growth of mycelium was observed after 4 to 5 days of incubation. Twenty isolates with conidial masses were recovered after 7 days of incubation. The isolates produced grayish white to grayish green and grey to moss dark green colony on PDA, pale orange conidial masses, and fusiform to cylindrical and hyaline conidia with an average size of 15 to 19 × 5 to 6 μm. Appresoria were ovate to obovate, dark brown, and 9 to 15 × 7 to 12 μm and setae were present, slightly swollen at the base, with a tapered apex, and brown. The cultural and morphological characteristics of the isolates were similar to those described for C. gleosporioides (1,2,3). All the C. gloeosporioides isolates were deposited in culture collection at Plant Pathology Lab, University Sains Malaysia. For confirmation of the identity of the isolates, ITS regions were sequenced using ITS4 and ITS5 primers. The isolates were deposited in GenBank with accessions JX163228, JX163231, JX163201, JX163230, JX163215, JX163223, JX163219, JX163202, JX163225, JX163222, JX163206, JX163218, JX163208, JX163209, JX163210, JX431560, JX163212, JX163213, JX431540, and JX431562. The resulting sequences showed 99% to 100% similarity with multiple C. gloeosporioides isolates in GenBank. Pathogenicity tests were conducted using mas, berangan, awak, nangka, and rastali bananas. Fruit surfaces were sterilized with 70% ethanol and wounded using a sterile scalpel. Two inoculation techniques were performed separately: mycelia plug and conidial suspension. Mycelial disc (5 mm) and a drop of 20 μl spore suspension (106 conidia/ml) were prepared from 7-day-old culture and placed on the fruit surface. The inoculated fruits were incubated at 27 ± 1°C for 10 days at 96.1% humidity. After 3 to 4 days of inoculation, brown to black spotted lesions were observed and coalesced to become black sunken lesions. Similar anthracnose symptoms were observed on all banana varieties tested. C. gloeosporioides was reisolated from the anthracnose lesions of all the inoculated fruit in which the cultural and morphological characteristics were the same as the original isolates. To our knowledge, this is the first report of C. gloeosporioides causing anthracnose of Musa spp. in Malaysia. References: (1) P. F. Cannon et al. Mycotaxon 104:189, 2008. (2) J. E. M. Mordue. Glomerella cingulata. CMI Description of Pathogenic Fungi and Bacteria, No. 315. CAB International,1971. (3) H. Prihastuti et al. Fungal Diversity 39:89, 2009.
    Matched MeSH terms: Citrus sinensis
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