DNA barcoding of arid wild plants using rbcL gene sequences.

DNA barcoding is currently gaining popularity due to its simplicity and high accuracy as compared to the complexity and subjective biases associated with morphology-based identification of taxa. The standard chloroplast DNA barcode for land plants recommended by the Consortium for the Barcode of Life (CBOL) plant working group needs to be evaluated for a wide range of plant species. We therefore tested the potential of the rbcL marker for the identification of wild plants belonging to diverse families of arid regions. Maximum likelihood tree analysis was performed to evaluate the discriminatory power of the rbcL gene. Our findings showed that using rbcL gene sequences enabled identification of the majority of the samples (92%) to genus level and only 17% to species level.

Application of RAPD for molecular characterization of plant species of medicinal value from an arid environment.

The use of highly discriminatory methods for the identification and characterization of genotypes is essential for plant protection and appropriate use. We utilized the RAPD method for the genetic fingerprinting of 11 plant species of desert origin (seven with known medicinal value). Andrachne telephioides, Zilla spinosa, Caylusea hexagyna, Achillea fragrantissima, Lycium shawii, Moricandia sinaica, Rumex vesicarius, Bassia eriophora, Zygophyllum propinquum subsp migahidii, Withania somnifera, and Sonchus oleraceus were collected from various areas of Saudi Arabia. The five primers used were able to amplify the DNA from all the plant species. The amplified products of the RAPD profiles ranged from 307 to 1772 bp. A total of 164 bands were observed for 11 plant species, using five primers. The number of well-defined and major bands for a single plant species for a single primer ranged from 1 to 10. The highest pair-wise similarities (0.32) were observed between A. fragrantissima and L. shawii, when five primers were combined. The lowest similarities (0) were observed between A. telephioides and Z. spinosa; Z. spinosa and B. eriophora; B. eriophora and Z. propinquum. In conclusion, the RAPD method successfully discriminates among all the plant species, therefore providing an easy and rapid tool for identification, conservation and sustainable use of these plants.

Interpretation of electrophoretograms of seven microsatellite loci to determine the genetic diversity of the Arabian Oryx.

Microsatellite markers are commonly used for examining population structure, especially inbreeding, outbreeding and gene flow. An array of microsatellite loci, preferably with multiallelic presentation, is preferable for ensuring accurate results. However, artifact peaks or stutters in the electrophoretograms significantly hamper the reliable interpretation of genotypes. We interpreted electrophoretograms of seven microsatellite loci to determine the genetic diversity of the Arabian Oryx. All the alleles of different loci exhibited good peak resolutions and hence were clearly identified. Moreover, none of the stutter peaks impaired the recognition or differentiation between homozygote and heterozygote. Our findings suggest that correct identification of alleles in the presence of co-amplified nonspecific fragments is important for reliable interpretation of microsatellite data.

Phylogenetic analysis of oryx species using partial sequences of mitochondrial rRNA genes.

We conducted a comparative evaluation of 12S rRNA and 16S rRNA genes of the mitochondrial genome for molecular differentiation among three oryx species (Oryx leucoryx, Oryx dammah and Oryx gazella) with respect to two closely related outgroups, addax and roan. Our findings showed the failure of 12S rRNA gene to differentiate between the genus Oryx and addax, whereas a 342-bp partial sequence of 16S rRNA accurately grouped all five taxa studied, suggesting the utility of 16S rRNA segment for molecular phylogeny of oryx at the genus and possibly species levels.

Application of 16S rRNA, cytochrome b and control region sequences for understanding the phylogenetic relationships in Oryx species.

The present study reports the application of mitochondrial markers for the molecular phylogeny of Oryx species, including the Arabian oryx (AO), scimitar-horned oryx (SHO) and plains oryx (PO), using the Addax as an outgroup. Sequences of three molecular markers, 16S rRNA, cytochrome b and a control region, for the above four taxa were aligned and the topologies of respective phylogenetic trees were compared. All these markers clearly differentiated the genus Addax from Oryx. However, for species-level grouping, while 16S rRNA and cytochrome b produced similar phylogeny (SHO grouped with PO), the control region grouped SHO with AO. Further studies are warranted to generate more sequencing data, apply multiple bioinformatics tools and to include relevant nuclear markers for phylogenetic analysis of Oryx species.

Toxicity of Nerium oleander and Rhazya stricta in Najdi sheep: hematologic and clinicopathologic alterations.

The toxic effects of oral administration of 0.25 g/kg Nerium oleander leaves, 0.25 g/kg Rhazya stricta leaves or their mixture at 0.25 g/kg N. oleander leaves plus 0.25 g/kg R. stricta leaves on Najdi sheep were investigated. Daily oral dosing of R. stricta leaves for 42 days was not fatal to sheep while single oral doses of either N. oleander leaves or the mixture with R. stricta leaves proved fatal to animals within 24 hours with dyspnea, grunting, salivation, grinding of the teeth, ruminal bloat, frequent urination, ataxia and recumbency prior to death. The main lesions were widespread congestion or hemorrhage, pulmonary cyanosis, emphysema, bronchotracheal froths, and hepatonephropathy. The clinical and pathological changes were correlated with alterations in serum LDH and AST activities and concentrations of cholesterol, bilirubin, urea, total protein, albumin, and globulin and hematological values.

Toxicological interactions of Cassia senna and Nerium oleander in the diet of rats.

The toxic effects of diet containing 10% of C. senna L. fruits or 10% of N. oleander L. leaves or their 1:1 mixture (5% + 5%) on male Wistar rats treated for 6 weeks were investigated. Diarrhea was a prominent sign of C. senna L. toxicosis. In both phytotoxicities, there were decreases in body weight gains, inefficiency of feed utilization, dullness and enterohepatonephropathy. These findings accompanied by leukopenia and anemia were correlated with alterations of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) activities and concentrations of total protein, albumin, urea and other serum constituents. In both phytotoxicities, the ability of the liver to excrete bilirubin remained unchanged. Feeding the mixture of C. senna L. fruits and N. oleander L. leaves caused more serious effects and death of rats. The implications of these findings are discussed.

Combined toxicity of Cassia senna and Citrullus colocynthis in rats.

Body weight loss, inefficiency of feed utilization, diarrhea, ruffled hair and enterohepatonephrotoxicity were effects on male Wistar rats fed diet containing 10% Cassia senna or 10% Citrullus colocynthis ripe fruits for 6w. Rats fed a 1:1 mixture (5% + 5%) of fruits from these plants were more adversely affected and had deaths than rats fed the individual plants. The changes associated with the macrocytic hypochromic anemia and leukopenia were increased serum AST, ALT and ALP activities, increased urea, and decreased total protein, albumin and calcium. Serum bilirubin concentration did not change.

Response of Najdi sheep to oral administration of Citrullus colocynthis fruits, Nerium oleander leaves or their mixture.

Susceptibility of sheep to oral administration of Citrullus colocynthis fruits, Nerium oleander leaves or their mixture is described in 12 sheep assigned as untreated controls, C. colocynthis-treated at 0.25g/kg/day, N. oleander-treated at 0.25g/kg and plant mixture-treated at 0.25g of C. colocynthis/kg plus 0.25g of N. oleander/kg. The daily use of 0.25g of C. colocynthis/kg for 42 days was not fatal to sheep and caused slight diarrhoea, catarrhal enteritis, centrilobular hepatocellular fatty change and degeneration of the renal tubular cells. Single oral doses of 0.25g of N. oleander/kg were lethal to sheep within 18-24h and caused uneasiness, grinding of the teeth, dyspnoea, anorexia, frequent urination, ruminal bloat, ataxia and recumbency before death. The main lesions were widespread congestion and haemorrhage, pulmonary cyanosis and emphysema and severe hepatonephropathy. Rapid death was also observed in sheep receiving single doses of the mixture of the two plants. Effects were correlated with changes in the activities of serum lactic dehydrogenase (LDH) and aspartate transaminase (AST) and concentrations of cholesterol, bilirubin, total protein, albumin, globulin and urea and haematological parameters.

Acute toxicity of various oral doses of dried Nerium oleander leaves in sheep.

The acute toxicity of dried Nerium oleander leaves to Najdi sheep is described in 12 sheep assigned as untreated controls, N. oleander-treated once at 1 and 0.25 g/kg body weight and N. oleander-treated daily at 0.06 g/kg body weight by drench. Single oral doses of 1 or 0.25 g of dried N. oleander leaves/kg body weight caused restlessness, chewing movements of the jaws, dyspnea, ruminal bloat, incoordination of movements, limb paresis, recumbency and death 4-24 hr after dosing. Lesions were widespread congestion or hemorrhage, pulmonary cyanosis and emphysema, hepatorenal fatty change and catarrhal abomasitis and enteritis. The daily oral doses of 0.06 g dried N. oleander leaves/kg body weight caused less severe signs and death occurred between days 3 and 14. In these animals, the main lesions were hepatonephropathy and gelatinization of the renal pelvis and mesentry and were accompanied by significant increases in serum AST and LDH activities, in bilirubin, cholesterol and urea concentrations and significant decreases in total protein and albumin levels, anemia and leucopenia.

Preliminary toxicity study on the individual and combined effects of Citrullus colocynthis and Nerium oleander in rats.

The toxicity of diet containing 10% of Citrullus colocynthis fruits or 10% of Nerium oleander leaves or their 1:1 mixture (5%+5%) for rats treated for 6 weeks was determined. Dullness, ruffled hair, decreased body weight gains and feed efficiency, and enterohepatonephropathy characterised treatment with C. colocynthis and N. oleander given alone. Diarrhoea was a prominent sign of C. colocynthis poisoning. Organ lesions were accompanied by leucopenia, anaemia and alterations in serum AST, ALT and ALP activities and concentrations of total protein, albumin, urea, bilirubin and other serum constituents. Feeding the mixture of C. colocynthis and N. oleander caused more marked effects and death of rats.

Effect of combined Citrullus colocynthis and Rhazya stricta use in Najdi sheep.

The effect of oral administration of 0.25 g/kg/day of Citrullus colocynthis fruits, 0.25 g/kg/day of Rhazya stricta leaves or mixture of the two plants at 0.25 g/kg/day of C. colocynthis fruits plus 0.25 g/kg/day of R. stricta leaves in Najdi sheep was examined. Oral administration of 0.25 g/kg/day of C. colocynthis fruits or 0.25 g/kg/day of R. stricta leaves for 42 days proved not fatal but that of the mixture of the two plants (0.25 g + 0.25 g/kg/day) proved fatal within 26 days with profuse diarrhea, dehydration, loss in condition, ataxia and recumbency, prior to death. These manifestations accompanied by enterohepatonephrotoxicity, gelatinization of the renal and epicardial fat and transudate in serous cavities were correlated with alterations in serum LDH and AST activities and concentrations of total protein, albumin, globulin, bilirubin, cholesterol and urea and hematology.