Rhizosphere and rhizoplane fungi of Triticum vulgare cultivated in Saudi Arabia

131 species in addition to 7 varieties which belong to 40 genera were collected from the rhizosphere (36 genera and 120 species + 7 varieties) and rhizoplane (27 genera and 56 species + 2 varieties) of Triticum vulgare. More than 22 species and 3 varieties were not encountered previously from soils or other sources in Saudi Arabia.In the rhizosphere, Aspergillus and Penicillium contributed the broadest spectrum of species (26 species + 5 varieties; and 24 species, respectively). The most frequent fungi were Aspergillus niger, A. clavatus, A. flavus, A. terreus, A. carneus, Penicillium citrinum, P. notatum, P. chrysogenum and Fusarium solani. In the rhizoplane which is a more selective substratum for fungi than the rhizosphere, the picture of dominance became different and the most common fungi were Fusarium solani, F. oxysporum, F. moniliforme, Drechslera spicifera, Cephalosporium roseo-griseum, Stemphylium botryosum, Acremonium strictum and Rhizoctonia solani.     

Medicinal plants in southwestern Saudi Arabia

Folk medicine practiced in southwestern Saudi Arabia has helped people prevent and cure various diseases and sicknesses such as rheumatism, asthma, diabetes, stomach problems, constipation, eye and ear problems, colds, fever, measles, bladder and urinary diseases, toothache, epilepsy, and skin allergy. The most common medicinal plants found in the region belong to the Leguminosae, Labiatae, Compositae, and Euphorbiaceae.     

Osmophilic fungi of desert soils in Saudi Arabia

100 osmophilic species in addition to two varieties which belong to 38 genera were isolated from desert soils of Saudi Arabia. The most prevalent genera were Asperngillus, Altemaria, Penicillium, Cephalosporium, Acremonium and Botryotrichum which occurred in 55–97.5% of the samples contributing 1.8–45.2% of total fungi. From the preceding genera A. amstelodami, A. fumigatus, A. terreus, A. niger, A. flavipes, A. repens, A. alternata, P. notatum, P. chrysogenum, P. citrinum, C.? racifi, A. strictum and B. atrogriseum were the most common. Five genera were recovered in moderate frequency namely, Ulocladium, Fusarium, Drechslera, Microascus, Syncephalastrum and Cladosporium which emerged in 25–42% of the samples comprising 0.7–2.8% of total fungi. The results obtained in the present investigation reveal that the fungus flora of Saudi Arabian soils is of osmophilic nature.     

Halophilic fungi of desert soils in Saudi Arabia

Twenty-five genera and sixty-eight species, in addition to one variety of each of A. chevalieri, A. flavus and A. nidulans were isolated from 40 soil samples collected from desert in Saudi Arabia on 5% sodium chloride-Czapek's agar. The most frequent genera were Aspergillus (20 species + 3 varieties), Penicillium (14 species), Drechslera (2 species) and Ulocladium (3 species), followed by Stemphylium (1 species), Scopulariopsis (2 species), Trichoderma (1 species) Botryotrichum (2 species), Cladosporium (3 species), Myrothecium (1 species) and Alternaria (1 species). From these genra A. amstelodami, A. chevalieri, A. ruber, A. ochraceus, P. brevi-compactum, P. ?cyano-fulvum, P. notatum, D. spicifera, U. consortiale, S. botryosum, S. brevicaulis, T. viride, B. piluliferum, C. herbarum, M. verrucaria and A. alterata were the most common. The results obtained in this investigation reveal that the fungus flora of Saudi Arabian soils is of halophilic nature.     

Cellulose-decomposing fungi of desert soils in Saudi Arabia

Seventy-five species in addition to 5 varieties of cellulose-decomposing which belong to 27 genera were collected during this investigation. Aspergillus (12 species + 4 varieties), Alternaria (4 species), Stachybotrys (3 species + 1 variety), and Penicillium (12 species) were of high frequency of occurrence, of which A. fumigatus, A. niger, A. terreus, A. alternata, A. tenuissima, S. atra, P. citrinum and P. corylophilum were the most common. Six genera were of moderate frequency and these were Botryotrichum (2 species), Macrophomina (1 species), Drechslera (5 species), Ulocladium (4 species), Chaetomium (7 species) and Curvularia (4 species) of which B. atrogriseum, D. spicifera, D. sativus, Ubotrytis, C. spirale and C. lunata were the most prevalent. Five and twelve genera were recovered on cellulose-Czapek's agar plates in low and rare frequency of occurrence, respectively.     

Viable airborne fungi in Riyadh, Saudi Arabia

An aerobiological study to identify and quantify allergenic fungi and their seasonal fluctuations was conducted at two different sites, (Al-Batha, a more developed area in the south and Al-Ulia, a less developed area in the north) in Riyadh city, using portable Personal Volumetric Air Sampler (Burkard Manufacturing Co., England). Sampling was conducted twice a week in both the morning and in the afternoon at both sites, for a period of 12 months. Airborne fungi were grouped into major and minor components depending upon their frequency of appearance and catch percentage in the air. Cladosporium spp., Penicillium spp., Aspergillus spp., Alternaria spp. and Ulocladium spp. were included as major components. Minor components included Drechslera spp., Rhizopus spp., Fusarium spp. and Stachybotryis spp. In general, higher concentrations of fungi were found at the developed (Al-Batha) site than at the less developed (Al-Ulia) site, both in the morning and in the afternoon.     

Seed-borne fungi in domestic bird feed in Saudi Arabia

Seed-borne fungi from seeds of barley, canary, maize, oats, rice, rapeseed, red millet, sunflower, white millet and yellow millet were investigated. These seeds are available in the market as bird feed, supplied by companies in various countries as healthy and nutritious food for domestic birds. A total of 81 fungal species were isolated. The genusAspergillus was predominant with 23 species, followed byPenicillium with 18,Ulocladium with 7,Alternaria with 6 andChaetomium, Curvularia andDrechslera with 5 species each. Other genera isolated wereAureobasidium, Cladosporium, Fusarium, Mucor, Rhizopus andSyncephalastrum.     

Rhizosphere communication of plants, parasitic plants and AM fungi

Plants use an array of secondary metabolites to defend themselves against harmful organisms and to attract others that are beneficial. However, the attraction of beneficial organisms could also lead to abuse by malevolent organisms. An exciting example of such abuse is the relationship between plants, beneficial mutualistic arbuscular mycorrhizal fungi and harmful parasitic plants. Signalling molecules called strigolactones, which are secreted by plant roots in low concentrations, induce the growth of both obligate biotrophs. Here, we review the importance of strigolactones for these two interactions and discuss possible developments that should further clarify the role of these signalling molecules in rhizosphere processes.     

Rhizosphere soil fungi of some vegetable plants

Summary The fungi from the rhizosphere and non-rhizosphere soils of some important vegetable crop plants, viz.,Lycopersicon esculentum, Allium cepa, Trigonella foenum-graecum, Daucus carota, Hibiscus esculentus, Raphanus sativus, andBrassica oleradcea were isolated. Some members of Phycomycetes, Acsomycetes and Fungi Imperfecti were isolated.It has also been observed that the pH in the region of the rhizosphere was lower and the moisture content was higher than in the soil away from it. Further, the maximum number of fungi was found in the rhizosphere of young plants. The present studies also supported the view that the number of fungi in the rhizosphere is greater than in the soil away from it. The largest number of fungi was obtained from the rhizosphere ofTrigonella foenum-graecum.     

Antimony accumulation and antioxidative responses in four fern plants

Antimony (Sb) toxicity and contamination has become a growing concern in recent years. Remediation of Sb contamination using plants may be an effective approach. This study aimed to investigate the potential of antimony (Sb) tolerance and accumulation by plants, as well as to understand the antioxidative responses to Sb. One set of hydroponic trials was set up using four species of fern plants, including Pteris cretica (PCA), Microlepia hancei (MH), Cyrtomium fortunei (CYF) and Cyclosorus dentatus (CYD). Ferns were grown for 2 weeks in nutrient solution containing a medium (5 mg L^?1) and a high (20 mg L^?1) rate of Sb, with no Sb added as the control. The biomass of fern PCA remained constant with Sb addition, whereas the biomass of ferns CYF, MH and CYD at the high Sb rate exposure decreased by 12.5%, 35.0% and 38.3%, respectively as compared with their controls. This suggests a high to low Sb tolerance order for these four fern plants. For all of these fern plants, more Sb was accumulated in the roots than in the fronds. Antimony concentration in the roots at the high rate of Sb addition was recorded, on average, as 358 mg kg^?1 for fern PCA, 224 mg kg^?1 for fern CYF, 124 mg kg^?1 for fern CYD and 123 mg kg^?1 for fern MH. A high rate of addition of Sb increased the contents of malondialdehyde (MDA) by 41.3% and 171.6% for ferns MH and CYD, respectively, as compared with their controls. No changes for MDA contents were observed in ferns PCA and CYF with Sb addition, indicating no lipid peroxidation reaction in these two plants. At a medium rate of Sb addition, the activities of peroxidase, catalase and ascorbate peroxidase in fern PCA were much higher than those in ferns CYF, CYD and MH, demonstrating the important role of these three enzymes in resisting Sb toxicity. The consistency in unchanged biomass, high accumulation of Sb in roots, lower MDA contents, as well as high enzyme production in fronds, indicated that fern PCA was more tolerant to Sb than the other three fern plants. Antioxidative enzymes (peroxidase, catalase and ascorbate peroxidase) might be involved in Sb toxicity resistance of fern PCA.     

Thermophilic and thermotolerant fungi in the desert soils of Saudi Arabia

Forty-eight thermophilic and thermotolerant species in addition to 5 varieties which belong to 24 genera were collected from desert soils in Saudi Arabia on glucose-(22 genera and 38 species + 5 varieties), cellulose-(15 genera and 27 species + 4 varieties) and 40% sucrose-Czapek's agar plates (13 genera and 26 species + 4 varieties) at 45 °C. The most frequent species were as follows: Aspergillus fumigatus, A. terreus, Humicola grisea var. thermoidae and Chaetomium thermophile var. copropile on glucose-; A. fumigatus, C. thermophile var. copropile, A. terreus, A. nidulans and C. thermophile var. dissitum on cellulose-; and A. fumigatus and A. terreus on 40% sucrose-Czapek's agar plates. Sixteen species and 4 varieties were particularly thermophilic and these were A. fumigatus, H. grisea var. thermoidae, H. insolens, H. lanuginosa, C. thermophile var. copropile, C. thermophile var. dissitum, C. virginicum, M. pusillus, S. thermophila, S.? pulverulentum, T. thermophilus, T.? emersoni, T. aurantiacus, T. thermophila, M. pulchella var. sulfurea, M. albomyces, ?A. terrestris, C. pruinosum, T. thermophila and P. thermophila. The remaining species showed different degrees of thermotolerant (32 species + 1 variety).     

Dermatophyte and non dermatophyte fungi in Riyadh City,Saudi Arabia

BackgroundDermatophytes are a scientific label for a group of three genera (Microsporum, Epidermophyton and Trichophyton) of fungus that causes skin disease in animals and humans. Conventional methods for identification of these fungi are rapid and simple but are not accurate comparing to molecular methods.ObjectiveThis study aimed to isolate human pathogenic dermatophytes which cause dermatophytosis in Riyadh City, Saudi Arabia and to identify these fungi by using conventional and molecular methods.MethodsThe study was conducted in Medical Complex, Riyadh and King Saud University. Samples of infected skin, hairs and nails were collected from 112 patients. Diagnosis of skin infections, direct microscopic test, isolation and identification of dermatophytes by conventional and molecular methods were carried out.ResultsThe results indicated that the tinea capitis infection had the highest prevalence among the patients (22.3%) while Tinea barbae had the lowest. In this study the identified dermatophyte isolates belong to nine species as Trichophyton violaceum, Trichophyton verrucosum, Trichophyton rubrum, Trichophyton mentagrophytes, Trichophyton schoenleinii, Trichophyton concentricum, Microsporum canis, Microsporum audouinii and Epidermophyton floccosum which cause skin infections were isolated during this study. Non dermatophyte isolates included 5 isolates from Aspergillus spp. 4 isolates from Acremonium potronii and 15 isolates from Candida spp. M. canis were the most common species (25% of isolated dermatophytes). Out of the 52 dermatophyte isolates identified by conventional methods, there were 45 isolates identified by the molecular method.ConclusionsThe results concluded that approximately M. canis caused a quarter of dermatophyte cases, tinea capitis infection was prevalent and the molecular method was more accurate than conventional methods.     

Detection of new viruses in alfalfa,weeds and cultivated plants growing adjacent to alfalfa fields in Saudi Arabia

A total of 1368 symptomatic plant samples showing different virus-like symptoms such as mottling, chlorosis, mosaic, yellow mosaic, vein clearing and stunting were collected from alfalfa, weed and cultivated plant species growing in vicinity of alfalfa fields in five principal regions of alfalfa production in Saudi Arabia. DAS-ELISA test indicated occurrence of 11 different viruses in these samples, 10 of which were detected for the first time in Saudi Arabia. Eighty percent of the alfalfa samples and 97.5% of the weed and cultivated plants samples were found to be infected with one or more of these viruses. Nine weed plant species were found to harbor these viruses namely, Sonchus oleraceus, Chenopodium spp., Hibiscus spp., Cichorium intybus, Convolvulus arvensis, Malva parviflora, Rubus fruticosus, Hippuris vulgaris, and Flaveria trinervia. These viruses were also detected in seven cultivated crop plants growing adjacent to the alfalfa fields including Vigna unguiculata, Solanum tuberosum, Solanum melongena, Phaseolus vulgaris, Cucurbita maxima, Capsicum annuum, and Vicia faba. The newly reported viruses together with their respective percent of detection in alfalfa, and in both weeds and cultivated crop plant species together were as follows: Bean leaf roll virus (BLRV) {12.5 and 4.5%}, Lucerne transient streak virus (LTSV) {2.9 and 3.5%}, Bean yellow mosaic virus (BYMV) {1.4 and 4.5%}, Bean common mosaic virus (BCMV) {1.2 and 4.5%}, Red clover vein mosaic virus (RCVMV) {1.2 and 4%}, White clover mosaic virus (WCIMV) {1.0 and 5%}, Cucumber mosaic virus (CMV) {0.8 and 3%}, Pea streak virus (PeSV) {0.4 and 4.5%} and Tobacco streak virus (TSV) {0.3 and 2.5%}. Alfalfa mosaic virus (AMV), the previously reported virus in alfalfa, had the highest percentage of detection in alfalfa accounting for 58.4% and 62.8% in the weeds and cultivated plants. Peanut stunt virus (PSV) was also detected for the first time in Saudi Arabia with a 66.7% of infection in 90 alfalfa samples collected from the surveyed regions during the last visit that tested negative to all the previously detected viruses.     

Mycotoxins producing fungi and mycoflora of air-dust from Taif,Saudi Arabia

Using the dilution plate method, 70 species and 31 genera were collected from 20 dust samples on glucose (28 genera and 64 species) and cellulose Czapek's agar (22 genera and 46 species) at 28° C. The most common fungi were Aspergillus niger, A. flavus, A. flavus var. columnaris, Phoma glomerata, Fusarium oxysporum, Penicillium chrysogenum and Mucor racemosus; and A. nidulans, Phoma humicola, Drechslera spicifera and Stachybotrys chartarum on the two media, respectively.Toxicity test showed that about 85% of the isolates tested were toxic to brine shrimp (Artemia salina). Thin layer chromatographic analysis revealed that 13 out of 23 toxic isolates produced known mycotoxins. Toxins identified were: aflatoxins B₁ and B₂, Kojic acid and trichodermine.     

Biological activity of fungi from the phyllosphere of weeds and wild herbaceous plants

Antimicrobial, phytotoxic, and insecticidal activity of 30 fungal isolates obtained from leaves of weeds and wild herbaceous plants was assessed. Antibacterial, antifungal, phytotoxic, and insecticidal activity was found in over 50%, 40, 47, and 40% of the isolates, respectively. These findings may be important for toxicological assessment of potential mycoherbicides, and may also provide a basis for investigation of the patterns of development of phyllosphere communities affected by fungal metabolites.     

Contamination of common spices in Saudi Arabia markets with potential mycotoxin-producing fungi

Fifteen spices obtained from common markets were examined for their mould profile. A total of 520 fungal isolates, representing 57 species, were recovered and identified from dried and ground spice samples on three different media using standard dilution plate method. The most heavily contaminated spice samples examined were observed in ginger in order of magnitude of 5325–6800 cfu/g. The most predominant fungal genera encountered were Aspergillus, Penicillium, and Rhizopus. Relative occurrence values of taxa disclosed ranged between 80% for Aspergillusflavus, Aspergillusniger and Penicilliumarenicola, and 10% for some species. Samples obtained from sumac encountered very rare colony counts indicating its antifungal prosperities. The present magnitude of contamination and spectra of mycobiota approximate those reported for similar spice samples. Several potentially mycotoxigenic fungi were isolated from the majority of samples. The present study attracts the attention to potential risk for mycotoxins contamination may be caused as a result of using these spices, especially in great quantities. The study strongly recommends reduction in application of heavily contaminated spices like ginger in food processing and using some others like clove and sumac due to their antimicrobial properties.     

Composition of the fungal flora of four cereal grains in Saudi Arabia

Using the grain-plate method and on glucose-Czapek's agar at 28°C, fifty-eight species belonging to 26 genera were collected from barley (42 species and 19 genera), maize (29 species and 16 genera), sorghum (32 species and 17 genera) and wheat grains (42 species and 18 genera).The most frequent genera were Aspergillus, Penicillium, Rhizopus, Fusarium, and Mucor followed by Alternaria, Drechslera, and Curvularia. From the preceding genera Aspergillus flavus, A. niger, Penicillium notatum, Rhizopus stolonifer, Fusarium moniliforme, Mucor racemosus, Alternaria alternata, Drechslera spicifera, and Curvularia lunata were the most prevalent species in the four types of grains tested.     

Medicinal plants used in Jeddah,Saudi Arabia: Phytochemical screening

Ethnobotanical and phytochemical studies are useful to discover new drugs. Phytochemical screening is an important step in the detection of the bioactive components existing in medicinal plants that are used in traditional medicine. Very few phytochemical studies investigating medicinal plants used in traditional medicine exist in Saudi Arabia. Eighty-five medicinal plants used in traditional medicine in Jeddah, Saudi Arabia are investigated here for the first time. This research aims to screen of 85 medicinal plants used in traditional medicine in Jeddah for the presence of secondary metabolites, and to answer the following question: Is the ethnomedicinal importance of medicinal plants used in Jeddah conform to their secondary metabolite content. Ethnobotanical fieldwork took place in Jeddah from August 2018 to September 2019. Eighty-five different plant species belonging to 37 families were identified. Screening of 85 medicinal plants was performed for the presence of alkaloids, glycosides, flavonoids, tannins, saponins and resins using standard methods. The most commonly distributed phytochemical compounds among medicinal plants used were glycosides (82%; 70 species), tannins (68%; 58 species), alkaloids (56%; 48 species), saponins (52%, 44 species) and flavonoids (35%; 30 species). On the other hand, the least commonly distributed compounds were resins (31%; 26 species). All the six groups of secondary metabolites were found in seeds of Cuminum cyminum L., Pimpinella anisum L. and Trigonella foenum-graecum L. It can be said that the ethnomedicinal importance of these 85 medicinal plants used in Jeddah conform to their secondary metabolite content. More research should be carried out on the quantitative analysis of phytochemicals in these 85 medicinal plants used in traditional medicine in Jeddah. Furthermore, there is a need to focus phytochemical screening on ethnobotanical studies to complete research into traditional medicine which leads to the discovery of new drugs.     

Molecular identification of isolated fungi from stored apples in Riyadh,Saudi Arabia

Fungi causes most plant disease. When fruits are stored at suboptimal conditions, fungi grows, and some produce mycotoxin which can be dangerous for human consumption. Studies have shown that the Penicillium and Monilinia species commonly cause spoilage of fruits, especially apples. Several other genera and species were reported to grow to spoil fruits. This study was conducted to isolate and identify fruit spoilage by fungi on apples collected in Riyadh, Saudi Arabia and conduct a molecular identification of the fungal isolates. Thus, we collected 30 samples of red delicious and Granny Smith apples with obvious spoilage from different supermarkets between February and March of 2012 in Riyadh, Saudi Arabia. Each apple was placed in a sterile plastic bag in room temperature (25–30 °C) for six days or until fungal growth was evident all over the sample. Growth of fungal colonies on PDA was counted and sent for molecular confirmation by PCR. Six fruit spoilage fungi were isolated, including Penicillium chrysogenum, Penicillium adametzii, Penicillium chrysogenum, Penicillium steckii, Penicillium chrysogenum, and Aspergillus oryzae. P. chrysogenum was the most frequent isolate which was seen in 14 of a total of 34 isolates (41.2%), followed by P. adametzii and A. oryzae with seven isolates each (20.6%) and the least was P. steckii with six isolates (17.6%). Penicillium species comprised 27 of the total 34 (79.4%) isolates. Sequence analysis of the ITS regions of the nuclear encoded rDNA showed significant alignments for P. chrysogenum, P. adametzii and A. oryzae. Most of these fungal isolates are useful and are rarely pathogenic; however they can still produce severe illness in immune-compromised individuals, and sometimes otherwise healthy people may also become infected. It is therefore necessary to evaluate the possible production of mycotoxins by these fungi to determine a potential danger and to establish its epidemiology in order to develop adequate methods of control.