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.     

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.     

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.     

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).     

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.     

Occurrence and distribution of tomato seed-borne mycoflora in Saudi Arabia and its correlation with the climatic variables

One hundred samples of tomato seeds were collected in 2011 and 2012 from tomato-cultivated fields in Saudi Arabia and screened for their seed-borne mycoflora. A total of 30 genera and 57 species of fungi were recovered from the collected seed samples using agar plate and deep-freezing blotter methods. The two methods differed as regards the frequency of recovered seed-borne fungi. Seven fungi among those recovered from tomato seeds, which are known as plant pathogens, were tested for their pathogenicity and transmission on tomato seedlings. The recovery rate of these pathogens gradually decreased from root up to the upper stem, and did not reach to the stem apex. The distribution of tomato seed-borne fungi was also investigated throughout Saudi Arabia. In this concern, Al-Madena governorate recorded the highest incidence of fungal flora associated with tomato seeds. The impact of meteorological variables on the distribution of tomato seed-borne mycoflora was explored using the ordination technique (canonical correspondence analysis). Among all climatic factors, relative humidity was the most influential variable in this regard. Our findings may provide a valuable contribution to our understanding of future global disease change and may be used also to predict disease occurrence and fungal transfer to new uninfected areas.     

Mating frequency of Apis mellifera jemenitica under desert conditions of Saudi Arabia

Queen mating frequency is an important reproductive trait of the western honeybee Apis mellifera. Yet, it demands more attention when investigated under extreme or confined ecosystems. Queen mating frequency of the Yemeni Honeybee A. m. jemenetica was estimated under Saudi Arabia desert conditions, Riyadh (24°71′36″N, 46°67′53″E). Mating of queens took place after 8–13 days from emergence. Duration of mating flight ranged between 26 and 39 min. Subsequently, six microsatellite loci were used to genotype queen's progeny (n = 30 workers/queen). The average number of drone alleles using workers genotypes ranged between 5.83 ± 0.31 and 6.33 ± 1.09. However, effective paternal allele number was extremely low and ranged between 3.35 ± 0.34 and 3.60 ± 0.40. This relatively low mating frequency of the Yemeni honeybee, A. m. jemenetica, might have striking effect on the overall colony survival. Providentially, this relatively low mating frequency does not impact colonial heterozygosity, shown in this study (0.66 ± 0.07–70 ± 0.04), adversely. These results may affect hive survivability and entails distinctive management practices under such conditions.     

Survey of airborne fungus spores at Taif,Saudi Arabia

Fifty-eight species and one variety belonging to 25 genera were collected from the atmosphere of Taif from August 1981 to July 1982 (12 exposures for each type of media) on glucose- and cellulose-Czapek's agar plates at 28 °C.The total counts of sugar and cellulose-decomposing airborne fungi showed seasonal fluctuations; the maxima were recorded in winter, and the minima in summer months. Aspergillus (16.23% and 13.22% of total fungi on glucose and cellulose media, respectively), Alternaria (11.52% and 15.7%), Cladosporium (18.59% and 9.5%), Drechslera (4.7% and 10.74%), Scopulariopsis (7.33% and 6.6%) and phoma (8.12% and 11.98%) were recovered in high seasonal occurrence on the two media. Also, Penicillium (on glucose) and Ulocladium (on cellulose) were common in the air accounting for 10.73% and 7.44% of total fungi, respectively.     

Study on the mycoflora of Egyptian soils

Fifty genera and 155 species, in addition to three varieties of Aspergillus nidulans, were isolated from 100 soil samples collected from different localities in Egypt. Aspergillus (33 species in addition to 3 varieties of A. nidulans), Penicillium (46 species), Fusarium (6 species) and Mucor (4 species) were of high occurrence, from which A. niger, A. fumigatus, A. terreus, M. racemosus, P. notatum, P. chrysogenum and A. flavus were dominant. Five genera were of moderate occurrence and these were Humicola, Myrothecium, Rhizopus, Cochliobolus and Alternaria. Fourteen genera were of low occurrence namely, Cunninghamella, Chaetomium, Stachybotrys, Cladosporium, Syncephalastrum, Paecilomyces, Trichoderma, Scolecobasidium, Circinella, Curvularia, Ulocladium, Botryotrichum, Sepedonium and Gliocladium. Twenty-seven genera were of rare occurrence.Fourteen species were of moderate occurrence and these were A. sydowii, M. verrucaria, P. funiculosum, A. versicolor, H. grisea, F. oxysporum, A. nidulans, F. moniliforme, A. alternata, F. solani, M. hiemalis, A. candidus, R. nigricans and A. ochraceus. The remaining species were of low or rare occurrence in soils tested.Comparison between the present results and those of others showed that there is no fungal flora characteristic cultivated soils.     

Impact of off-road vehicles on soil and vegetation in a desert rangeland in Saudi Arabia

Off-road vehicle driving is considered as main contributor to land degradation in arid regions. This study examined the impact of off-road vehicles (ORV) on soil and vegetation in a natural recreational desert meadow of Raudhat Khuraim, Saudi Arabia. Vegetation canopy cover and plant height away from road tracks were assessed. Also, species density and canopy cover, bare ground cover and soil attributes were assessed in four microhabitats; tracks, inter-tracks, verges, and away from vehicle tracks (undisturbed natural areas). Results show that the cover of forbs and grasses was negatively associated with distance from road verges. It was observed that the height of woody species responded negatively to distance away from tracks. Cover of native species decreased under verge, inter-track and track microhabitats giving more opportunity for weeds to flourish. Bare ground was highest (60.7%) in tracks. ORV impact on soil bulk density was clear with an increase of 38% under tracks compared to soils of undisturbed natural vegetation and a similar decrease in porosity was observed. On the other hand, soil electrical conductivity was significantly higher (5.45 mS cm^?1) under disturbance compared to 1.32 mS cm^?1 in undisturbed natural vegetation. Organic matter and nitrogen were not affected significantly by ORV disturbance. The results emphasize that managing off-road vehicle driving is essential for conserving native vegetation.     

Survey of mange mite infesting sheep in Riyadh region,Saudi Arabia

The study was performed to survey the Sarcoptic mange in sheep and the effect of infection on the local strains during a specific period in different regions of Riyadh, Saudi Arabia. A total of 1745 sheep were examined clinically and were selected from the suspected cases for laboratory investigation of skin scrapings for disease diagnosis. The examined animals included (509) Naimi, (396) Najdi, (518) Hurri, and (322) Rufidi native sheep.The results showed that the infestation rate was (12.77%) in all sheep. The highest strain was recorded (17.2%, 14.3%, 9.6%, and 8.6%), respectively. The infestation was highest in sheep over two years of age (15.2%) while it was lowest in sheep under two years of age (11.2 %). In addition, the infection rate in females was higher than in males. The prevalence of mange mites in females was (14%) compared to (11.2%) in males. The highest percentage of infestation was recorded in the head region at 67.2%, followed by that in the neck (4.4%), back (16.5%), tail (11.6%), and legs (0%).The presence of mange mites was discovered by microscopic examination of deep skin scrapings of infected animals that were identified morphologically. The infection was assured by histological investigations. This study revealed that mange mite is one of the most significant sheep health constraints in Riyadh. Therefore, proper prevention measures must be implemented to take into consideration other non-host-related risk factors.     

Characterizing physical and hydraulic properties of soils in Al-Ahsa,Kingdom of Saudi Arabia

Al-Ahsa Oasis is one of the oldest and biggest agricultural regions in Saudi Arabia. Thirty-six soil samples representing most of the soil type in the region were collected and analysed in a laboratory for physical properties including particle size (sand%, silt%, clay%), saturation θ_s, and bulk density ρ. The soil–water characteristic curve (SWCC) was measured using the filter paper method. Intensive statistical analysis included correlation, stepwise multiple linear regression analysis (SWR), mean square error (MSE), and F-test were used to evaluate the potential PTFs. Silt (silt%) and bulk density (ρ) were achieved a high accuracy in prediction of (ρ) and saturation (θ_s) respectively. Both field capacity (FC) and wilting point (WP) were correlated significantly with θ_s with a very high prediction compatibility and MSE 0.004 and 0.001 respectively. Using tow levels of prediction demonstrated high correctness in predicting SWCC with correlation coefficient 0.986 and 0.952 with a low MSE equal to 0.0007 and 0.0028 respectively. The result of this study shown the high feasibility of developing a model for the prediction of SWCC using easily readable PTFs.     

Development of skin structure and cutaneous water loss in nestling desert house sparrows from Saudi Arabia

The outer layer of the epidermis, the stratum corneum (SC), contains lipids and corneocytes, which together form layers that limit cutaneous water loss (CWL). We examined the development of structure of the SC and CWL in nestling House Sparrows (Passer domesticus) from Saudi Arabia. We measured CWL of nestlings, and characterized development of their epidermis using electron microscopy. We tested two antagonistic hypotheses, that CWL decreases as nestlings age, a response to increased thickness of SC, and an opposite idea that CWL increases as nestlings age even though the number of layers of the SC remains constant. CWL of nestling House Sparrows varied with developmental stages, in a non-linear fashion, but not significantly so. CWL of nestlings averaged 7.31+/-1.5 g H(2)O/(m(2) h), whereas for adults it was 4.95 g/(m(2) h); adult CWL was 67.7% that of nestlings. We found that morphology of the SC did not change linearly with age, but seemed to vary with developmental stage. CWL decreased as the SC thickness increased and as the total thickness of the corneocytes increased. Further, we found that CWL decreased as the thickness of the extracellular space increased, number of corneocytes increased, and proportion of the SC that is extracellular space increased.     

Selenium status in Saudi Arabia

Selenium (Se) is a naturally occurring trace element that is essential for animal and human nutrition, but the range between dietary requirements and toxic levels is relatively narrow. In this review, we are interested in the beneficial effects of selenium and we report on a number of studies of the selenium status of different populations in Saudi Arabia. The Status reflects the geographical area inhabited by the populations. Apart from the few available studies reviewed here, no data on the human status of Se in Saudi Arabia has been obtained. A further objective of this paper is throw some the light on the direction of future studies.     

Cytological studies of certain desert mammals of Saudi Arabia 5. The karyotype of Meriones rex

Male and female specimens of Meriones rex were collected from agricultural areas of Asir province in Saudi Arabia. The mitotic and meiotic chromosomes were analysed and the diploid number of chromosomes was found to be 38. The karyotype showed 24 metacentric, 10 submetacentric and 2 acrocentric autosomes. The sex chromosomes were represented by a medium-sized metacentric X and a small metacentric Y chromosome. The fundamental number (FN) was 74.This project has been supported by Research Center of College of Science, King Saud University (Zoo/1402/11), Riyadh, Saudi Arabia.     

Survey of the mycoflora of barley grains in Egypt

The fungi of 40 samples of barley grains collected from Upper Egypt were estimated using the dilution- and the grain-plate methods. 33 genera and 109 species, in addition to 2 varieties of Aspergillus nidulans, one variety of Aspergillus flavus and one variety of Penicillium cyclopium were identified. The spectrum of fungal genera and species collected by the grain-plate method (29 genera and 94 species+3 varieties) was broader than by the dilutionplate method (27 genera and 71 species+3 varieties), but the order of frequency of occurrence of fungal genera and species was basically similar in the two methods. The most frequent genera were Aspergillus (25 species+3 varieties), Penicillium (32 species+1 variety), Rhizopus (2 species), Alternaria (2 species), Fusarium (6 species) and Drechslera (5 species) and were represented (as assayed by the grainplate method) in 100 %, 77.5 %, 85 % 62,5 %, 60 % and 52.5 % of the samples constituting 60.4 %, 10.2 %, 7.7 %, 3.7 %, 5 % and 2.3 % of the gross total count of fungi respectively. From the preceding genera A. niger, A. fumigatus, A. flavus, A. sydowii, P. notatum, P. citrinum, F. oxysporum, F. moniliforme, F. solani, R. stolonifer, A. alternata and D. spicifera were the most frequent.     

Preimplantation genetic diagnosis in Saudi Arabia

Preimplantation genetic diagnosis (PGD) testing is the practice of obtaining a cellular biopsy sample from a developing human oocyte or embryo, acquired via a cycle of in vitro fertilization (IVF); evaluating the genetic composition of this sample; and using this information to determine which embryos will be optimal for subsequent uterine transfer. PGD has become an increasingly useful adjunct to IVF procedures. The ability to provide couples who are known carriers of genetic abnormalities the opportunity to deliver healthy babies has opened a new frontier in reproductive medicine. The purpose of the PGD is enables us to choose which embryos will be implanted into the mother. In the present study 137 families who had undergone IVF at Habib Medical Centre, were enrolled for the PGD analysis. The couple visited the clinic for the sex selection, recurrent fetal loss and with the recurrent IVF failure. 802 embryos were tested by the biopsy method and 512 are found to be normal and 290 were abnormal embryos. In this study only 24% of the embryos were transferred and the remaining was not transferred because of the abnormalities or undesired sex of the embryos. The structural and numerical abnormalities were found to be 16.8%.