Luma al-Banna - Academia.edu (original) (raw)

Papers by Luma al-Banna

Elemental analysis of the roots, stems, leaves, and fruits of tomato was performed using scanning... more Elemental analysis of the roots, stems, leaves, and fruits of tomato was performed using scanning electron microscopy equipped with energy–dispersive X-ray spectroscopy (SEM-EDS) and Atomic absorption spectroscopy (AAS). irrigation water of tomato plants were found free from heavy toxic metals, (Zn, Cd, Co, Cr, Mn), but have traces of Cu and Pb. Traces of Zn, Cu, Cr, Pb, and Mn were detected in the soil. EDS analysis showed that toxic heavy metals Pb, Co, Cr, Mn, Ti, Zn, and Cu were detected and accumulated in the roots system of tomato, only Pb tranbsfered from the root to stems. Fe found to be accumulated in all parts of tomato plant.

The development of green synthesis route for the synthesis of nanomaterials using plants extract ... more The development of green synthesis route for the synthesis of nanomaterials using plants extract have received attention in the recent times as it is environment eco-friendly and economical method. Zinc sulfide nanoparticles (ZnSNPs) have been synthesized using Punica granatum (Pomegranate) peel aqueous extract at ambient temperature and in one single step. The synthesized zinc sulfide nanoparticles were investigated by X-ray diffraction (XRD), Energy dispersive analysis of X-rays (EDS), Scanning electron microscopy (SEM), UV-vis optical absorption and Fourier transform infrared spectroscopy (FTIR). UV-vis absorption studies revealed surface plasmon resonance (SPR) peak around 308nm, confirming the presence of ZnS nanoparticles. Particle size could be controlled by changing the quantity of peel extract andzinc ion concentration. Results of this study revealed that ZnSNPs have the potential to enhance root and development growth of cucumber plant.

Jordan Journal of Agricultural Sciences, Oct 17, 2021

We used nucleotide sequences of the large subunit ribosomal genes (26S rDNA) to examine evolution... more We used nucleotide sequences of the large subunit ribosomal genes (26S rDNA) to examine evolutionary relationships among species of the genus Pratylenchus (Order: Tylenchida, Family: Pratylenchidae), commonly known as root-lesion nematodes. Ten species of Pratylenchus were studied including, P. penetrans, P. crenatus, P. minyus, P. vulnus, P. thornei, P. musicale, P. coffeae, P. bexincisus, P. scribneri, and P. brachyurus. The species Hirschmanniella belli, Meloidogyne javanica, Heterorhabditis bacteriophora, Nacobbus eberruns, Radopholus similis, and Xiphinema index were used as outgroups. Based on parsimony analyses of approximately 307 aligned nucleotides of the D3 expansion region of the 26S rDNA, it is clear that species of Pratylenchus are a paraphyletic assemblage. The outgroup taxon H. belli shares a common ancestor with the clade that includes P. vulnus and P. crenatus while N. aberrans and R. similis share a common ancestor with 5 other species included in this study

Individuals of a new species of trichostrongyloid nematode of the genus Vexillata were collected ... more Individuals of a new species of trichostrongyloid nematode of the genus Vexillata were collected from the intestines of the coarse-haired pocket mouse, Chaetodipus hispidus, from eastern New Mexico. This new species possesses general features of the genus Vexillata but may be recognized as distinct from all other species by unique features of the dorsal ray of the caudal bursa and the synlophe

From 1990 through 1992, nematodes were extracted from soil samples taken from the rhizosphere of ... more From 1990 through 1992, nematodes were extracted from soil samples taken from the rhizosphere of native species of grapes from four areas of northern California and two areas of southern California. For comparison, samples from domestic grapes as well as a putative hybrid of Vitis californicaand V. vinifera were also taken. Rhizosoil from California native grapevine contained many more species of nematodes than did soil obtained from cultivated forms of V. vinifera. Taxonomic and trophic diversity was much higher in nematodes from sampling sites from native grapes than in those from grapes maintained in vineyard situations. Ordination methods using correspondence analysis showed both similarities and differences in the faunal assemblages of nematodes from the different sampling sites, based on indexes of species and trophic groups. Collected data indicate that nematode communities with high trophic and taxonomic diversity have a lower numerical density of plant parasites. De 1990 a ...

Received on 23/4/2009 and Accepted for Publication on 23/10/2012. ABSTRACT The effect of the init... more Received on 23/4/2009 and Accepted for Publication on 23/10/2012. ABSTRACT The effect of the initial inoculum on the reproduction of the Mediterranean cereal cyst nematode Heterodera latipons on barley was studied. Two types, cysts or second stage juveniles (J2), of initial inoculum (Pi) were used in this investigation. Four inoculum levels of cysts (0, 5, 10, or 20/pot filled with 500 g clay loam soil) and J2 (0, 100, 200, or 400 J2s/ pot filled with 100 g clay loam soil) were used. The results indicated that the multiplication of H. latipons increased as the Pi increased while the reproduction factor decreased. The results also showed that increasing of initial inoculum, cysts or J2, of H. latipons resulted in decreasing the plant height, fresh and dry weight of both shoots and roots of barley.

Reference Module in Life Sciences, 2022

World Journal of …, 2006

The soil-borne bacterium Bacillus thuringiensis (Bt) is an important biological agent used agains... more The soil-borne bacterium Bacillus thuringiensis (Bt) is an important biological agent used against human and plant pests and diseases. Seven Jordanian Bt isolates, which have been analysed for toxicity against important pests, were also differentiated through serotyping. In this study, they were analysed at the molecular level using random amplified polymorphic DNA markers. Five more international strains were incorporated in the analysis. The DNA markers used showed high polymorphism among the isolates tested. However, the data did not align completely with earlier serotyping for most isolates. Therefore, it is recommended to engage several analyses (e.g. biochemical and molecular) when classifying newly surveyed Bt isolates in the world.

ISSN: 2410-9649 Al Banna et al / Chemistry International 6(3) (2020) 137-143 iscientic.org. 138 w... more ISSN: 2410-9649 Al Banna et al / Chemistry International 6(3) (2020) 137-143 iscientic.org. 138 www.bosaljournals/chemint/ editorci@bosaljournals.com et al., 2011). These methods have many disadvantages due to the difficulty of scale up the process, separation and purification of nanoparticles from the micro emulsions and energy requirements. Developing facile and green methods for synthesizing sulfur nanoparticles are of importance and still a challenge for materials researchers(Alvarez-Bayona et al., 2019; da Silva et al., 2019; Jayarambabu et al., 2020; Pan et al., 2019; Ravichandran et al., 2019; Vidovix et al., 2019). Using plants extracts as reducing, stabilizing agents for green synthesis of S-NPs were reported in the literature such as Melia Azedarach leaves extract (Salem et al., 2016a), Ailanthus altissima leaves extract (Salem et al., 2016b), Punica granatum leaf extract (Salem et al., 2016c), herbal surfactant (Kouzegaran and Farhadi, 2017), Albizia julibrissin fruits ex...

Summary. The effects of two local strains of Bacillus thuringiensis, Bt. pakistani (H13) and Bt. ... more Summary. The effects of two local strains of Bacillus thuringiensis, Bt. pakistani (H13) and Bt. erztomocidus (Hb), on hatching and mortality of two root knot nematode species, Meloidogyne incognita and M. jauanica, were studied under laboratory conditions. Two concentrations, IO5 and 106 viable spores/ml, of each Bt strain were tested. Exposure of juveniles to 106viable spores/ml caused 100% mortality of juveniles of both species oi nematode. Similarly, significant reduction of hatch was observed from eggs within the gelatinous matrix or freed eggs exposed to IO6 viable spores/ml of both Bt strains. At the lower concentration of Bt spores, significant reduction in hatch was detected with freed eggs of M. incognita but not with eggs of M. javanica. No reduction of hatch from egg masses of either species was found after exposure to IO5 viable spores/ml. In Jordan, there are two dominant species of root knot nematodes, Meloidogyne jauanica (Treub) Chitw. and M. zncognita (Kofoid et Wh...

Jordan Journal of Agricultural Sciences, 2010

Four Jordanian strains of Bacillus thuringiensis, (Bt) i.e. Bt jordanica, Bt kurstaki, Bt pakista... more Four Jordanian strains of Bacillus thuringiensis, (Bt) i.e. Bt jordanica, Bt kurstaki, Bt pakistani, and Bt thuringiensis, and two reference strains Bt israelensis and Bt kurstaki were tested against root knot nematodes, Meloidogyne incognita and M. javanica. Exposing freed eggs or eggs within eggmasses to 106 viable spores/ml of each local strain resulted in either complete inhibition or few J2s hatching of both nematode species. Lower concentrations (105 viable spores /ml) were less effective in reducing egg hatching. Depending on the local Bt strains, 100% mortality of J2 of both nematodes occurred either after 2, 4 or 6 days of exposure to the higher spore concentration. Lower concentration of Bt strains was less effective but with a significant increase of mortality of J2s of both nematodes.

Jordan Journal of Agricultural Sciences, 2010

Fifty bacterial isolates of Pseudomonas syringae pv. tomato (Okabe) the causal agent of bacterial... more Fifty bacterial isolates of Pseudomonas syringae pv. tomato (Okabe) the causal agent of bacterial speck of tomato, were isolated and identified from diseased tomato samples collected from different tomato growing areas in Jordan. The 650 bp coronatine genes cluster was detected in all Ps. syringae pv. tomato tested isolates by using Two 17-bp oligonucleotide primers; primer 1 and primer 2 by PCR analysis. To detect variation among the tested isolates of Pseudomonas syringae pv. tomato, the 650 bp PCR products of the six different isolates present in six different locations were digested with five restriction enzymes namely; PstI, ClaI, SmaI, CfoI and HaeIII. Fragments of identical sizes were obtained from these isolates, which prove that this gene cluster is highly conserved. Moreover, the Pseudomonas syringae pv. tomato was found to be translocated systemically throughout the infected tomato shoots, since this pathogen was detected by direct isolation on KB medium followed by patho...

Jordan Journal of Agricultural Sciences, 2013

The effect of the initial inoculum on the reproduction of the Mediterranean cereal cyst nematode ... more The effect of the initial inoculum on the reproduction of the Mediterranean cereal cyst nematode Heterodera latipons on barley was studied. Two types, cysts or second stage juveniles (J2), of initial inoculum (Pi) were used in this investigation. Four inoculum levels of cysts (0, 5, 10, or 20/pot filled with 500 g clay loam soil) and J2 (0, 100, 200, or 400 J2s/ pot filled with 100 g clay loam soil) were used. The results indicated that the multiplication of H. latipons increased as the Pi increased while the reproduction factor decreased. The results also showed that increasing of initial inoculum, cysts or J2, of H. latipons resulted in decreasing the plant height, fresh and dry weight of both shoots and roots of barley.

Jordan Journal of Agricultural Sciences, 2010

Field surveys were conducted to asses the incidence of Tomato ringspot virus (ToRSV , genus Nepov... more Field surveys were conducted to asses the incidence of Tomato ringspot virus (ToRSV , genus Nepovirus, Family Comoviridae) infection in stone fruit trees in Jordan during 2000-2002. A total of 2546 samples, collected from commercial orchards, a mother block, nurseries and a varietal collection were tested for ToRSV infection by DAS-ELISA. Results showed that 16% of the tested samples were infected with the virus. The disease incidence percentages in apricot, almond, peach, nectarine, plum and cherry trees were 10, 14, 15, 19, 22 and 28% of the tested trees, respectively. The level of viral infection was highest in the commercial orchards (20%) and lowest in samples obtained from nurseries (5%).

SUMMARY The Mediterranean cereal cyst nematode, Heterodera latipons, attacks barley grown in the ... more SUMMARY The Mediterranean cereal cyst nematode, Heterodera latipons, attacks barley grown in the Northern and Southern Mediterranean phytogeographical zones and Eastern Desert of Jordan with variation in incidence and severity. The aim of this study was to clone a candidate parasitism gene from local populations of H. latipons. These targeted genes encode secretory protein products. Three populations of H. latipons from Ar-Ramtha, Madaba and Dana were identified. Morphological studies were used for all populations to confirm species identity before any molecular work. Pectate lyase and chorismate genes were the target genes. Therefore primers were designed based on alignment from H. latipons. Certain primer combinations showed amplicons using genomic DNA (directly from second-stage juveniles). A total of 35 amplicons were cloned and 18 of them were sent for sequencing. These clones were analysed using Blastx searches against sequences in NCBI databases. Blastx resulted in similariti...

From 1990 through 1992, nematodes were extracted from soil samples taken from the rhizosphere of ... more From 1990 through 1992, nematodes were extracted from soil samples taken from the rhizosphere of native species of grapes from four areas of northern California and two areas of southern California. For comparison, samples from domestic grapes as well as a putative hybrid of Vitis califarnica and V. vinifera were also taken. Rhizosoil from California native grapevine contained many more species of nematodes than did soil obtained from cultivated forms of V. vinifera. Taxonomic and trophic diversity was much higher in nematodes from sampling sites from native grapes than in those from grapes maintained in vineyard situations. Ordination methods using correspondence analysis showed both similarities and differences in the faunal assemblages of nematodes from the different sampling sites, based on indexes of species and trophic groups. Collected data indicate that nematode communities with high trophic and taxonomic diversity have a lower numerical density of plant parasites. Resume: D...

A PCR-based assay for identification of six species of Pratylenchus common in California is descr... more A PCR-based assay for identification of six species of Pratylenchus common in California is described. In this assay, five forward species-specific primers were designed from the internal variable portion of the D3 expansion region of the 26S rDNA and were each used with a single, common reverse primer. The optimized species-specific primers produced unique amplicons from their respective target and did not amplify DNA from other Pratylenchus species. With this assay we were able to identify single females to species level. This method obviates the need for subsequent RFLP or sequence analysis of the PCR product and can be used as a rapid diagnostic tool in epidemiological and management studies.

Elemental analysis of the roots, stems, leaves, and fruits of tomato was performed using scanning... more Elemental analysis of the roots, stems, leaves, and fruits of tomato was performed using scanning electron microscopy equipped with energy–dispersive X-ray spectroscopy (SEM-EDS) and Atomic absorption spectroscopy (AAS). irrigation water of tomato plants were found free from heavy toxic metals, (Zn, Cd, Co, Cr, Mn), but have traces of Cu and Pb. Traces of Zn, Cu, Cr, Pb, and Mn were detected in the soil. EDS analysis showed that toxic heavy metals Pb, Co, Cr, Mn, Ti, Zn, and Cu were detected and accumulated in the roots system of tomato, only Pb tranbsfered from the root to stems. Fe found to be accumulated in all parts of tomato plant.

The development of green synthesis route for the synthesis of nanomaterials using plants extract ... more The development of green synthesis route for the synthesis of nanomaterials using plants extract have received attention in the recent times as it is environment eco-friendly and economical method. Zinc sulfide nanoparticles (ZnSNPs) have been synthesized using Punica granatum (Pomegranate) peel aqueous extract at ambient temperature and in one single step. The synthesized zinc sulfide nanoparticles were investigated by X-ray diffraction (XRD), Energy dispersive analysis of X-rays (EDS), Scanning electron microscopy (SEM), UV-vis optical absorption and Fourier transform infrared spectroscopy (FTIR). UV-vis absorption studies revealed surface plasmon resonance (SPR) peak around 308nm, confirming the presence of ZnS nanoparticles. Particle size could be controlled by changing the quantity of peel extract andzinc ion concentration. Results of this study revealed that ZnSNPs have the potential to enhance root and development growth of cucumber plant.

Jordan Journal of Agricultural Sciences, Oct 17, 2021

We used nucleotide sequences of the large subunit ribosomal genes (26S rDNA) to examine evolution... more We used nucleotide sequences of the large subunit ribosomal genes (26S rDNA) to examine evolutionary relationships among species of the genus Pratylenchus (Order: Tylenchida, Family: Pratylenchidae), commonly known as root-lesion nematodes. Ten species of Pratylenchus were studied including, P. penetrans, P. crenatus, P. minyus, P. vulnus, P. thornei, P. musicale, P. coffeae, P. bexincisus, P. scribneri, and P. brachyurus. The species Hirschmanniella belli, Meloidogyne javanica, Heterorhabditis bacteriophora, Nacobbus eberruns, Radopholus similis, and Xiphinema index were used as outgroups. Based on parsimony analyses of approximately 307 aligned nucleotides of the D3 expansion region of the 26S rDNA, it is clear that species of Pratylenchus are a paraphyletic assemblage. The outgroup taxon H. belli shares a common ancestor with the clade that includes P. vulnus and P. crenatus while N. aberrans and R. similis share a common ancestor with 5 other species included in this study

Individuals of a new species of trichostrongyloid nematode of the genus Vexillata were collected ... more Individuals of a new species of trichostrongyloid nematode of the genus Vexillata were collected from the intestines of the coarse-haired pocket mouse, Chaetodipus hispidus, from eastern New Mexico. This new species possesses general features of the genus Vexillata but may be recognized as distinct from all other species by unique features of the dorsal ray of the caudal bursa and the synlophe

From 1990 through 1992, nematodes were extracted from soil samples taken from the rhizosphere of ... more From 1990 through 1992, nematodes were extracted from soil samples taken from the rhizosphere of native species of grapes from four areas of northern California and two areas of southern California. For comparison, samples from domestic grapes as well as a putative hybrid of Vitis californicaand V. vinifera were also taken. Rhizosoil from California native grapevine contained many more species of nematodes than did soil obtained from cultivated forms of V. vinifera. Taxonomic and trophic diversity was much higher in nematodes from sampling sites from native grapes than in those from grapes maintained in vineyard situations. Ordination methods using correspondence analysis showed both similarities and differences in the faunal assemblages of nematodes from the different sampling sites, based on indexes of species and trophic groups. Collected data indicate that nematode communities with high trophic and taxonomic diversity have a lower numerical density of plant parasites. De 1990 a ...

Received on 23/4/2009 and Accepted for Publication on 23/10/2012. ABSTRACT The effect of the init... more Received on 23/4/2009 and Accepted for Publication on 23/10/2012. ABSTRACT The effect of the initial inoculum on the reproduction of the Mediterranean cereal cyst nematode Heterodera latipons on barley was studied. Two types, cysts or second stage juveniles (J2), of initial inoculum (Pi) were used in this investigation. Four inoculum levels of cysts (0, 5, 10, or 20/pot filled with 500 g clay loam soil) and J2 (0, 100, 200, or 400 J2s/ pot filled with 100 g clay loam soil) were used. The results indicated that the multiplication of H. latipons increased as the Pi increased while the reproduction factor decreased. The results also showed that increasing of initial inoculum, cysts or J2, of H. latipons resulted in decreasing the plant height, fresh and dry weight of both shoots and roots of barley.

Reference Module in Life Sciences, 2022

World Journal of …, 2006

The soil-borne bacterium Bacillus thuringiensis (Bt) is an important biological agent used agains... more The soil-borne bacterium Bacillus thuringiensis (Bt) is an important biological agent used against human and plant pests and diseases. Seven Jordanian Bt isolates, which have been analysed for toxicity against important pests, were also differentiated through serotyping. In this study, they were analysed at the molecular level using random amplified polymorphic DNA markers. Five more international strains were incorporated in the analysis. The DNA markers used showed high polymorphism among the isolates tested. However, the data did not align completely with earlier serotyping for most isolates. Therefore, it is recommended to engage several analyses (e.g. biochemical and molecular) when classifying newly surveyed Bt isolates in the world.

ISSN: 2410-9649 Al Banna et al / Chemistry International 6(3) (2020) 137-143 iscientic.org. 138 w... more ISSN: 2410-9649 Al Banna et al / Chemistry International 6(3) (2020) 137-143 iscientic.org. 138 www.bosaljournals/chemint/ editorci@bosaljournals.com et al., 2011). These methods have many disadvantages due to the difficulty of scale up the process, separation and purification of nanoparticles from the micro emulsions and energy requirements. Developing facile and green methods for synthesizing sulfur nanoparticles are of importance and still a challenge for materials researchers(Alvarez-Bayona et al., 2019; da Silva et al., 2019; Jayarambabu et al., 2020; Pan et al., 2019; Ravichandran et al., 2019; Vidovix et al., 2019). Using plants extracts as reducing, stabilizing agents for green synthesis of S-NPs were reported in the literature such as Melia Azedarach leaves extract (Salem et al., 2016a), Ailanthus altissima leaves extract (Salem et al., 2016b), Punica granatum leaf extract (Salem et al., 2016c), herbal surfactant (Kouzegaran and Farhadi, 2017), Albizia julibrissin fruits ex...

Summary. The effects of two local strains of Bacillus thuringiensis, Bt. pakistani (H13) and Bt. ... more Summary. The effects of two local strains of Bacillus thuringiensis, Bt. pakistani (H13) and Bt. erztomocidus (Hb), on hatching and mortality of two root knot nematode species, Meloidogyne incognita and M. jauanica, were studied under laboratory conditions. Two concentrations, IO5 and 106 viable spores/ml, of each Bt strain were tested. Exposure of juveniles to 106viable spores/ml caused 100% mortality of juveniles of both species oi nematode. Similarly, significant reduction of hatch was observed from eggs within the gelatinous matrix or freed eggs exposed to IO6 viable spores/ml of both Bt strains. At the lower concentration of Bt spores, significant reduction in hatch was detected with freed eggs of M. incognita but not with eggs of M. javanica. No reduction of hatch from egg masses of either species was found after exposure to IO5 viable spores/ml. In Jordan, there are two dominant species of root knot nematodes, Meloidogyne jauanica (Treub) Chitw. and M. zncognita (Kofoid et Wh...

Jordan Journal of Agricultural Sciences, 2010

Four Jordanian strains of Bacillus thuringiensis, (Bt) i.e. Bt jordanica, Bt kurstaki, Bt pakista... more Four Jordanian strains of Bacillus thuringiensis, (Bt) i.e. Bt jordanica, Bt kurstaki, Bt pakistani, and Bt thuringiensis, and two reference strains Bt israelensis and Bt kurstaki were tested against root knot nematodes, Meloidogyne incognita and M. javanica. Exposing freed eggs or eggs within eggmasses to 106 viable spores/ml of each local strain resulted in either complete inhibition or few J2s hatching of both nematode species. Lower concentrations (105 viable spores /ml) were less effective in reducing egg hatching. Depending on the local Bt strains, 100% mortality of J2 of both nematodes occurred either after 2, 4 or 6 days of exposure to the higher spore concentration. Lower concentration of Bt strains was less effective but with a significant increase of mortality of J2s of both nematodes.

Jordan Journal of Agricultural Sciences, 2010

Fifty bacterial isolates of Pseudomonas syringae pv. tomato (Okabe) the causal agent of bacterial... more Fifty bacterial isolates of Pseudomonas syringae pv. tomato (Okabe) the causal agent of bacterial speck of tomato, were isolated and identified from diseased tomato samples collected from different tomato growing areas in Jordan. The 650 bp coronatine genes cluster was detected in all Ps. syringae pv. tomato tested isolates by using Two 17-bp oligonucleotide primers; primer 1 and primer 2 by PCR analysis. To detect variation among the tested isolates of Pseudomonas syringae pv. tomato, the 650 bp PCR products of the six different isolates present in six different locations were digested with five restriction enzymes namely; PstI, ClaI, SmaI, CfoI and HaeIII. Fragments of identical sizes were obtained from these isolates, which prove that this gene cluster is highly conserved. Moreover, the Pseudomonas syringae pv. tomato was found to be translocated systemically throughout the infected tomato shoots, since this pathogen was detected by direct isolation on KB medium followed by patho...

Jordan Journal of Agricultural Sciences, 2013

The effect of the initial inoculum on the reproduction of the Mediterranean cereal cyst nematode ... more The effect of the initial inoculum on the reproduction of the Mediterranean cereal cyst nematode Heterodera latipons on barley was studied. Two types, cysts or second stage juveniles (J2), of initial inoculum (Pi) were used in this investigation. Four inoculum levels of cysts (0, 5, 10, or 20/pot filled with 500 g clay loam soil) and J2 (0, 100, 200, or 400 J2s/ pot filled with 100 g clay loam soil) were used. The results indicated that the multiplication of H. latipons increased as the Pi increased while the reproduction factor decreased. The results also showed that increasing of initial inoculum, cysts or J2, of H. latipons resulted in decreasing the plant height, fresh and dry weight of both shoots and roots of barley.

Jordan Journal of Agricultural Sciences, 2010

Field surveys were conducted to asses the incidence of Tomato ringspot virus (ToRSV , genus Nepov... more Field surveys were conducted to asses the incidence of Tomato ringspot virus (ToRSV , genus Nepovirus, Family Comoviridae) infection in stone fruit trees in Jordan during 2000-2002. A total of 2546 samples, collected from commercial orchards, a mother block, nurseries and a varietal collection were tested for ToRSV infection by DAS-ELISA. Results showed that 16% of the tested samples were infected with the virus. The disease incidence percentages in apricot, almond, peach, nectarine, plum and cherry trees were 10, 14, 15, 19, 22 and 28% of the tested trees, respectively. The level of viral infection was highest in the commercial orchards (20%) and lowest in samples obtained from nurseries (5%).

SUMMARY The Mediterranean cereal cyst nematode, Heterodera latipons, attacks barley grown in the ... more SUMMARY The Mediterranean cereal cyst nematode, Heterodera latipons, attacks barley grown in the Northern and Southern Mediterranean phytogeographical zones and Eastern Desert of Jordan with variation in incidence and severity. The aim of this study was to clone a candidate parasitism gene from local populations of H. latipons. These targeted genes encode secretory protein products. Three populations of H. latipons from Ar-Ramtha, Madaba and Dana were identified. Morphological studies were used for all populations to confirm species identity before any molecular work. Pectate lyase and chorismate genes were the target genes. Therefore primers were designed based on alignment from H. latipons. Certain primer combinations showed amplicons using genomic DNA (directly from second-stage juveniles). A total of 35 amplicons were cloned and 18 of them were sent for sequencing. These clones were analysed using Blastx searches against sequences in NCBI databases. Blastx resulted in similariti...

From 1990 through 1992, nematodes were extracted from soil samples taken from the rhizosphere of ... more From 1990 through 1992, nematodes were extracted from soil samples taken from the rhizosphere of native species of grapes from four areas of northern California and two areas of southern California. For comparison, samples from domestic grapes as well as a putative hybrid of Vitis califarnica and V. vinifera were also taken. Rhizosoil from California native grapevine contained many more species of nematodes than did soil obtained from cultivated forms of V. vinifera. Taxonomic and trophic diversity was much higher in nematodes from sampling sites from native grapes than in those from grapes maintained in vineyard situations. Ordination methods using correspondence analysis showed both similarities and differences in the faunal assemblages of nematodes from the different sampling sites, based on indexes of species and trophic groups. Collected data indicate that nematode communities with high trophic and taxonomic diversity have a lower numerical density of plant parasites. Resume: D...

A PCR-based assay for identification of six species of Pratylenchus common in California is descr... more A PCR-based assay for identification of six species of Pratylenchus common in California is described. In this assay, five forward species-specific primers were designed from the internal variable portion of the D3 expansion region of the 26S rDNA and were each used with a single, common reverse primer. The optimized species-specific primers produced unique amplicons from their respective target and did not amplify DNA from other Pratylenchus species. With this assay we were able to identify single females to species level. This method obviates the need for subsequent RFLP or sequence analysis of the PCR product and can be used as a rapid diagnostic tool in epidemiological and management studies.