Adel Abdel-Ghani | Mutah University (original) (raw)

Papers by Adel Abdel-Ghani

Plant Science, 2014

Background: Root growth and development is not only critical for nitrogen acquisition in plants, ... more Background: Root growth and development is not only critical for nitrogen acquisition in plants, but also to anchor the plant in the soil. Several genes involved in maize root development have been isolated. Identification of SNPs associated with root traits would enable the selection of maize lines with better root architecture that might help to improve N uptake, and consequently plant growth particularly under N deficient conditions. Results: In the present study, an association study (AS) panel consisting of 74 maize inbred lines was screened for seedling root traits in 6, 10, and 14-day-old seedlings. Allele resequencing of candidate root genes Rtcl, Rth3, Rum1, and Rul1 was also carried out in the same AS panel lines. All four candidate genes displayed different levels of nucleotide diversity, haplotype diversity and linkage disequilibrium. Nucleotide diversity was highest in the Rtcl gene (π=0.021), intermediate in Rum1 (π=0.011), lowest in Rth3 (π=0.007) and Rul1 (π=0.005) gene. When coding and non-coding regions within the genes were compared, nucleotide diversity varied across the genes. Gene based association analyses were carried out between individual polymorphisms in candidate genes, and root traits measured in 6, 10, and 14-day-old maize seedlings. Association analyses revealed several polymorphisms within the Rtcl, Rth3, Rum1, and Rul1 genes associated with seedling root traits. These significantly associated SNPs also affected putative functional sequence motifs, mostly transcription factor binding sites, and major domains in the genes. Conclusion: Several nucleotide polymorphisms in Rtcl, Rth3, Rum1, and Rul1 were significantly (P<0.05) associated with seedling root traits in maize suggesting that all four tested genes are involved in the maize root development. Thus considerable allelic variation present in these root genes can be exploited for improving maize root characteristics. Target nucleotide polymorphisms for functional marker development were identified which might find application in marker-based selection strategies in breeding programs.

Figure S1. Examples of scanned root images from individual plants. Figure S2. Concatenated split ... more Figure S1. Examples of scanned root images from individual plants. Figure S2. Concatenated split network tree for the collection of 233 accessions based on 6019 SNP markers. Figure S3. LD pattern along the individual chromosomes of barley. Figure S4. Schematic representation of the eight re-sequenced candidate genes models. (DOCX 3427 kb)

Table S1.Overview of 233 genotypes used in this study, their accession numbers, collection name, ... more Table S1.Overview of 233 genotypes used in this study, their accession numbers, collection name, origin, row type and biological status. Table S2.Candidate genes re-sequenced in the association panel with primer combinations used. Details are provided for amplified fragment sizes, primer combinations and annealing temperature Table S3.Summary statistics of ten root and shoot seedling traits and for DSI. Table S4.Estimates of variance components and broad sense heritabilities under non- stress and 15% PEG drought stress conditions. Table S5.Analysis of Molecular Variance (AMOVA) for the 233 diverse barley genotypes based on K = 9, employing 6019 SNP markers. Table S6.Influence of row-type on the phenotypic traits: t-test results and phenotypic mean values for both row-types. Table S7.Distribution of mapped SNPs across seven barley chromosomes, coverage and polymorphism information content (PIC). Table S8. Summary of the significant QTL. Trait names, SNP marker names, chromosome, gene...

The level of variation in various fruit traits was described among 14 Jordanian pomegranate landr... more The level of variation in various fruit traits was described among 14 Jordanian pomegranate landraces and the genetic relatedness was investigated using RAPD and SSR markers. Euclidean distances among studied landraces ranged from 3.33 to 12.01, with a mean of 7.65. Fruit and aril traits explained the variation in the first component (28.92%), while other traits were present in the second (17.615) and third (12.81%) component, and therefore contributed less to the variability. Genetic distances based on RAPD scores ranged from 0.24 to 0.66, indicating that considerable level of divergence exists among studied pomegranate landraces. The set of SSR markers used in this study was monomorphic, which might be due to the fact that available SSR markers are too few to identify polymorphic SSR markers to differentiate between landraces present within a small geographic area. Multivariate analysis showed that dendrograms constructed based on fruit related traits as compared with that based o...

Previous studies conducted at the University of Hohenheim and ICARDA indicated that yielding abil... more Previous studies conducted at the University of Hohenheim and ICARDA indicated that yielding ability and stability of barley (Hordeum vulgare L.) could be improved in environments with drought stress by increasing the level of heterozygosity. This could be accomplished by developing synthetic varieties composed of germplasm with a high outcrossing rate. As a first step, we characterized the genetic structure of barley landraces and H. spontaneum populations collected from various semi-arid localities in Jordan to obtain reliable estimates of the amount and variation of outcrossing in this germplasm. Natural outcrossing was estimated in 13 populations of H. spontaneum and 12 barley landraces from collection sites that covered high-low transects for rainfall and altitude to detect possible environmental effects on outcrossing rate. Four microsatellite markers were used to estimate the outcrossing rate based on maximum likelihood methods and mixed mating models. Low outcrossing rates w...

Jordan Journal of Agricultural Sciences, 2010

Nine hundred and twenty lines of durum wheat landraces collected from ten locations in Jordan and... more Nine hundred and twenty lines of durum wheat landraces collected from ten locations in Jordan and seven checks (Haurani 27, Acsad 65, Om Qais, Sham 3, Sham1, Sham 5 and Deiralla 6) were evaluated under field conditions in two contrasting environments (semi-arid and arid conditions) on the basis of single head row progeny. The objectives were to estimate phenotypic (PCV) and genetic (GCV) coefficients of variation, broad sense heritability (h2)and genetic advance (GA) using the variance components method based on the combined analyses over locations and the variance analyses for each location for various agro-morphological and phenological traitsand to determine the interrelationships among these traits. Because of high genotype × location (G × L) interactions, estimates of GCV, h2 and GA for different traits using combined analysis were generally lower than the estimates computed from the variance analyses made separately for each location. The high cross-over G × L interactions cou...

This study aimed at investigating sources of tolerance in wheat and barley against the cereal lea... more This study aimed at investigating sources of tolerance in wheat and barley against the cereal leafminer, Syringopais temperatella Led. (Lepidoptera: Scythrididae) under semi-arid climate of Jordan. In this study, 546 accessions of bread and durum wheat, and barley were screened. The initial screening of the accessions was performed in 2006/2007, and accessions that displayed a type of resistance to S. temperatella in the initial screening were re-evaluated in 2008/2009. The average insect damage score (based on a 1 to 6 damage scale) in the initial screening was 5.1, 5.3 and 6.0 for barley, bread wheat and durum wheat, respectively. The percentages of barley and bread wheat accessions exhibiting resistance were 12.4% and 1.0%, respectively, while 4.1% and 11.0% of the accessions were tolerant. The re-evaluation of the selected barley and bread wheat accessions in 2008/2009 revealed that all the selected accessions were moderately tolerant with damage mean score of 2.5 to 4.3. Howeve...

Variation of twelve Hyoscyamus aureus, four H. desertorum and two H. reticulatus populations from... more Variation of twelve Hyoscyamus aureus, four H. desertorum and two H. reticulatus populations from Jordan were investigated at the phenotypic level with morphological characters and at DNA level using the Random Amplified Polymorphic DNA (RAPD) technique. Sixteen morphological traits were measured after 100 days from planting. There was a significant difference among the collected populations in 12 out of 16 morphological traits. The three highly polymorphic selected primers generated 60 RAPD bands with 39.5% mean level of the proportion of polymorphic loci. Multivariate procedures using dendograms and Principle Coordinate Analysis (PCoA) were used to classify the collected populations on the basis of phenotypic traits and RAPD fragments. RAPD estimate of genetic relationships among Hyoscyamus species was consistent with morphological study results. From the cluster analyses using dendograms and PCoA, it appears that morphological traits and RAPD markers were useful to separate the p...

The effects of water deficit and nitrogen (N) application were evaluated on dry matter (DM) and N... more The effects of water deficit and nitrogen (N) application were evaluated on dry matter (DM) and N remobilization in eight durum wheat varieties. Cham5, Cham3, Om Quis, Kayar Tunis and Hourani Nawawi had the highest DM remobilization under wetter environment ranging from 16.7 to 16.8%, rising to 20.7 to 23.7% in the drier environment. Cham 5 and Cham 3 also showed higher N translocation to grains (values=67.3 and 72.9%) under drier conditions. N deficiency significantly (P<0.05) increased N remobilization to grain in Deir Alla 6 and Hourani Nawawi; increasing N rate from 0 to 200 kg urea ha-1 decreased N remobilization from 40.8 to 20.8% and from 40.3 to 32.3% in Deir Alla 6 and Hourani Nawawi, respectively. In conclusion, some varieties showed high capacity for DM and N translocation under unfavorable conditions and they could be considered as a potential source of genes for plant breeding.

Jordan Journal of Agricultural Sciences, 2013

Genetic diversity and population structure of 20 durum wheat (Triticum turgidum L. subsp. durum) ... more Genetic diversity and population structure of 20 durum wheat (Triticum turgidum L. subsp. durum) landrace populations collected from three eco-agricultural zones from Jordan were studied; using Random Amplified Polymorphic DNA (RAPD) markers. DNA from ten individuals (i.e. lines) per population was analyzed using 21 RAPD primers. A total of 148 reproducible bands were detected, of which 128 (86.5%) were polymorphic. Nei’s genetic distance varied from 0.07 to 0.33. The unweighted pair-group method of arithmetic average (UPGMA) tree based on the genetic distance revealed that populations collected from northern and southern zones were grouped into two separate clusters in line with their putative geographic origins. Populations collected from the central zone were found mixed with populations collected from the two other zones, indicating that the villages located in the geographical center of the study area have a frequent exchange of seeds with other villages from northern and south...

Jordan Journal of Agricultural Sciences, 2013

This study was carried out to examine the response of 14 barley varieties to drought imposed at d... more This study was carried out to examine the response of 14 barley varieties to drought imposed at different developmental stages (DDS). To examine the effect of drought stress (DS) on germination rate and seedlings growth, the seeds were exposed to induced osmotic potentials (OP; -0.75 and -1.2 Mpa), in addition to the control. Er/Apm variety did not show any significant decrease in germination rate in response to OP. The most drought tolerant varieties at seedling stage were Morocco9-75, Yarmouk, Acsad 176, and WI2291 with minimal biomass losses. Varieties were also tested against four DS treatments: continuous DS (Dcon), early DS (Dearly), late DS (Dlate) and a combination of Dearly and Dlate (Dearly+late) treatments. Grain yield in the control treatment (continuous irrigation) was almost two times greater than Dcon treatment, while the reductions in Dearly, Dlate and Dearly+late treatments were 12.9, 26.1, and 33.6% compared to the control treatment, respectively. WI2291 and Yarmou...

JULY 2020

Populations of barley landrace [Hordeum vulgare (L.)] and wild barley progenitor [Hordeum spontan... more Populations of barley landrace [Hordeum vulgare (L.)] and wild barley progenitor [Hordeum spontaneum (L.)] were collected from 13 diverse eco-geographical regions in Jordan. In addition to two check varieties (Rum and Acsad 165) were collected from farmers’ fields. In total, 28 genotypes were evaluated during germination, early seedling and maturity stages for salt tolerance. Barley populations were exposed to tap water of 0.85 dS m-1 and saline solutions (NaCl, CaCl2 and MgSO4) of 4, 8, 12 and 16 dS m-1. Final germination percentage, the lengths of shoot and seminal root, growth and yield related traits were significantly decreased by increasing the level of salinity. Proline content was increased by increasing the level of salinity. A high level of salinity of 16 dS m-1 had a strong impact on reduction of grain yield and other agronomic traits in the examined populations. A considerable variation among populations was detectable. Barley landrace and wild barley that were collected...

Crop Research

Calcareous soil is extremely important in determining nutrient status and availability when apply... more Calcareous soil is extremely important in determining nutrient status and availability when applying different fertilizers to different crops associated with or without irrigation. The objective of this study was to investigate the nutritional status (nutrient availability) of different plants grown in two different ecosystems dominated with calcareous soil : Ghor Alsafi (eggplants, tomato and beans) as an example of irrigated area and the Karak Mountain Area (wheat) as an example for non-irrigated area. Physiochemical properties in soils and nutrients concentrations (C, Fe, Mn, Zn, available P, available and non-available K) in soil and plant leaves were analyzed. This study showed that N concentration in soil from both Ghor Alsafi (ranged from 4.4-5.1 mg/g) and the Karak Mountain Area (1.9-3.2 mg/g) was relatively low. This study showed that Fe content in vegetables grown in Ghor Alsafi was about 3 to 5 fold higher than the recommended maximum Fe concentration. The concentration of other nutrients (N, K, Zn and Mn) in investigated vegetables fell within the recommended concentrations range (38.3-39.7 mg/g, 36.6-39.5 mg/g, 21.7-27.3 ppm and 49.2-102.6 ppm, respectively). Phosphorus content in vegetables grown in Ghor Alsafi and in wheat grown in different locations in the Karak Mountain Area was about 5?6 fold higher than the recommended P concentration. Our results indicated that the high levels of P (ranged from 3.28-3.43 mg/g) and Fe (ranged from 340.4-551.3 ppm) in vegetables grown in Ghor Alsafi and high levels of P (ranged from 2.2-2.52 mg/g) in wheat in the Karak Mountain Area can be attributed to high levels of fertilizer application.

BMC Plant Biology

Background: Adaptation to drought-prone environments requires robust root architecture. Genotypes... more Background: Adaptation to drought-prone environments requires robust root architecture. Genotypes with a more vigorous root system have the potential to better adapt to soils with limited moisture content. However, root architecture is complex at both, phenotypic and genetic level. Customized mapping panels in combination with efficient screenings methods can resolve the underlying genetic factors of root traits. Results: A mapping panel of 233 spring barley genotypes was evaluated for root and shoot architecture traits under non-stress and osmotic stress. A genome-wide association study elucidated 65 involved genomic regions. Among them were 34 root-specific loci, eleven hotspots with associations to up to eight traits and twelve stressspecific loci. A list of candidate genes was established based on educated guess. Selected genes were tested for associated polymorphisms. By this, 14 genes were identified as promising candidates, ten remained suggestive and 15 were rejected. The data support the important role of flowering time genes, including HvPpd-H1, HvCry2, HvCO4 and HvPRR73. Moreover, seven root-related genes, HERK2, HvARF04, HvEXPB1, PIN5, PIN7, PME5 and WOX5 are confirmed as promising candidates. For the QTL with the highest allelic effect for root thickness and plant biomass a homologue of the Arabidopsis Trx-m3 was revealed as the most promising candidate. Conclusions: This study provides a catalogue of hotspots for seedling growth, root and stress-specific genomic regions along with candidate genes for future potential incorporation in breeding attempts for enhanced yield potential, particularly in drought-prone environments. Root architecture is under polygenic control. The co-localization of well-known major genes for barley development and flowering time with QTL hotspots highlights their importance for seedling growth. Association analysis revealed the involvement of HvPpd-H1 in the development of the root system. The co-localization of root QTL with HERK2, HvARF04, HvEXPB1, PIN5, PIN7, PME5 and WOX5 represents a starting point to explore the roles of these genes in barley. Accordingly, the genes HvHOX2, HsfA2b, HvHAK2, and Dhn9, known to be involved in abiotic stress response, were located within stress-specific QTL regions and await future validation.

Plant Breeding

This study aimed at developing, characterizing and evaluating two maize phenotypic-selected intro... more This study aimed at developing, characterizing and evaluating two maize phenotypic-selected introgression libraries for a collection of dominant plant height (PHT)-increasing alleles by introgressing donor chromosome segments (DCS) from Germplasm Enhancement of Maize (GEM) accessions into elite inbred lines: PHB47 and PHZ51. Different backcross generations (BC1-BC4) were developed and the tallest 23 phenotype-selected introgression families (PIFs) from each introgression library (PHB47 or PHZ51) were selected for single nucleotide polymorphism genotyping to localize DCS underlying PHT. The result shows that most PIFs carrying DCS were significantly (α = 0.01) taller than the respective recurrent parent. In addition, they contained larger donor genome proportions than expected in the absence of selection or random mating across all BC generations. The DCS were distributed over the whole genome, indicating a complex genetic nature underlying PHT. We conclude that our PIFs are enriched for favourable PHTincreasing alleles. These two libraries offer opportunities for future PHT gene isolation and allele characterization and for breeding purposes, such as novel cultivars for biofuel production.

Jordan Journal of Agricultural Sciences, 2014

Diversity among eight Jordanian snake melon (Cucumis melo var. flexuosus) landrace populations wa... more Diversity among eight Jordanian snake melon (Cucumis melo var. flexuosus) landrace populations was studied by analyzing morphological traits and random amplified polymorphic DNA (RAPD) markers. Pair-wise euclidean distances based on morphological data ranged from 4.6 to 8.10 among studied populations. Fruit traits explained the variation in the first two components (15.5% and 13.6% of the total variation were explained by PC1 and PC2 respectively), while the leaf traits were consistently present in the third component and therefore contributed less to the variability (10.8%). A total of 11 RAPD primers produced 85 fragments, of which 94% were polymorphic indicating a high degree of diversity. RAPD based dendrogram showed Nei's values ranging from 0.07 to 0.23 suggesting that the collected populations are genetically diverse. The range of gene diversity, (He) among snake melon populations ranged from 0.17 to 0.27. The analysis of molecular variance (AMOVA) showed that genetic variation among populations accounted for 18.52% of the total variation, while more than 80% occurred within populations consistent with outcrossing nature of snake melon. In conclusion, Jordanian snake melon landraces must be considered as a reservoir of genes that plant breeders need in their snake melon improvement programs.

Jordan Journal of Agricultural Sciences, Dec 30, 2013

This study was carried out to examine the response of 14 barley varieties to drought imposed at d... more This study was carried out to examine the response of 14 barley varieties to drought imposed at different developmental stages (DDS). To examine the effect of drought stress (DS) on germination rate and seedlings growth, the seeds were exposed to induced osmotic potentials (OP;-0.75 and-1.2 Mpa), in addition to the control. Er/Apm variety did not show any significant decrease in germination rate in response to OP. The most drought tolerant varieties at seedling stage were Morocco9-75, Yarmouk, Acsad 176, and WI2291 with minimal biomass losses. Varieties were also tested against four DS treatments: continuous DS (Dcon), early DS (Dearly), late DS (Dlate) and a combination of Dearly and Dlate (Dearly+late) treatments. Grain yield in the control treatment (continuous irrigation) was almost two times greater than Dcon treatment, while the reductions in Dearly, Dlate and Dearly+late treatments were 12.9, 26.1, and 33.6% compared to the control treatment, respectively. WI2291 and Yarmouk showed the minimal grain yield losses in response to DS at DDS and their ranks in response to DS remained almost unchanged at DDS, and consequently they could be considered as a potential source of genes for drought tolerance.

Jordan Journal of Agricultural Sciences, Mar 24, 2014

Diversity among eight Jordanian snake melon (Cucumis melo var. flexuosus) landrace populations wa... more Diversity among eight Jordanian snake melon (Cucumis melo var. flexuosus) landrace populations was studied by analyzing morphological traits and random amplified polymorphic DNA (RAPD) markers. Pair-wise euclidean distances based on morphological data ranged from 4.6 to 8.10 among studied populations. Fruit traits explained the variation in the first two components (15.5% and 13.6% of the total variation were explained by PC1 and PC2 respectively), while the leaf traits were consistently present in the third component and therefore contributed less to the variability (10.8%). A total of 11 RAPD primers produced 85 fragments, of which 94% were polymorphic indicating a high degree of diversity. RAPD based dendrogram showed Nei's values ranging from 0.07 to 0.23 suggesting that the collected populations are genetically diverse. The range of gene diversity, (He) among snake melon populations ranged from 0.17 to 0.27. The analysis of molecular variance (AMOVA) showed that genetic variation among populations accounted for 18.52% of the total variation, while more than 80% occurred within populations consistent with outcrossing nature of snake melon. In conclusion, Jordanian snake melon landraces must be considered as a reservoir of genes that plant breeders need in their snake melon improvement programs.

Plant Science, 2014

Background: Root growth and development is not only critical for nitrogen acquisition in plants, ... more Background: Root growth and development is not only critical for nitrogen acquisition in plants, but also to anchor the plant in the soil. Several genes involved in maize root development have been isolated. Identification of SNPs associated with root traits would enable the selection of maize lines with better root architecture that might help to improve N uptake, and consequently plant growth particularly under N deficient conditions. Results: In the present study, an association study (AS) panel consisting of 74 maize inbred lines was screened for seedling root traits in 6, 10, and 14-day-old seedlings. Allele resequencing of candidate root genes Rtcl, Rth3, Rum1, and Rul1 was also carried out in the same AS panel lines. All four candidate genes displayed different levels of nucleotide diversity, haplotype diversity and linkage disequilibrium. Nucleotide diversity was highest in the Rtcl gene (π=0.021), intermediate in Rum1 (π=0.011), lowest in Rth3 (π=0.007) and Rul1 (π=0.005) gene. When coding and non-coding regions within the genes were compared, nucleotide diversity varied across the genes. Gene based association analyses were carried out between individual polymorphisms in candidate genes, and root traits measured in 6, 10, and 14-day-old maize seedlings. Association analyses revealed several polymorphisms within the Rtcl, Rth3, Rum1, and Rul1 genes associated with seedling root traits. These significantly associated SNPs also affected putative functional sequence motifs, mostly transcription factor binding sites, and major domains in the genes. Conclusion: Several nucleotide polymorphisms in Rtcl, Rth3, Rum1, and Rul1 were significantly (P<0.05) associated with seedling root traits in maize suggesting that all four tested genes are involved in the maize root development. Thus considerable allelic variation present in these root genes can be exploited for improving maize root characteristics. Target nucleotide polymorphisms for functional marker development were identified which might find application in marker-based selection strategies in breeding programs.

Figure S1. Examples of scanned root images from individual plants. Figure S2. Concatenated split ... more Figure S1. Examples of scanned root images from individual plants. Figure S2. Concatenated split network tree for the collection of 233 accessions based on 6019 SNP markers. Figure S3. LD pattern along the individual chromosomes of barley. Figure S4. Schematic representation of the eight re-sequenced candidate genes models. (DOCX 3427 kb)

Table S1.Overview of 233 genotypes used in this study, their accession numbers, collection name, ... more Table S1.Overview of 233 genotypes used in this study, their accession numbers, collection name, origin, row type and biological status. Table S2.Candidate genes re-sequenced in the association panel with primer combinations used. Details are provided for amplified fragment sizes, primer combinations and annealing temperature Table S3.Summary statistics of ten root and shoot seedling traits and for DSI. Table S4.Estimates of variance components and broad sense heritabilities under non- stress and 15% PEG drought stress conditions. Table S5.Analysis of Molecular Variance (AMOVA) for the 233 diverse barley genotypes based on K = 9, employing 6019 SNP markers. Table S6.Influence of row-type on the phenotypic traits: t-test results and phenotypic mean values for both row-types. Table S7.Distribution of mapped SNPs across seven barley chromosomes, coverage and polymorphism information content (PIC). Table S8. Summary of the significant QTL. Trait names, SNP marker names, chromosome, gene...

The level of variation in various fruit traits was described among 14 Jordanian pomegranate landr... more The level of variation in various fruit traits was described among 14 Jordanian pomegranate landraces and the genetic relatedness was investigated using RAPD and SSR markers. Euclidean distances among studied landraces ranged from 3.33 to 12.01, with a mean of 7.65. Fruit and aril traits explained the variation in the first component (28.92%), while other traits were present in the second (17.615) and third (12.81%) component, and therefore contributed less to the variability. Genetic distances based on RAPD scores ranged from 0.24 to 0.66, indicating that considerable level of divergence exists among studied pomegranate landraces. The set of SSR markers used in this study was monomorphic, which might be due to the fact that available SSR markers are too few to identify polymorphic SSR markers to differentiate between landraces present within a small geographic area. Multivariate analysis showed that dendrograms constructed based on fruit related traits as compared with that based o...

Previous studies conducted at the University of Hohenheim and ICARDA indicated that yielding abil... more Previous studies conducted at the University of Hohenheim and ICARDA indicated that yielding ability and stability of barley (Hordeum vulgare L.) could be improved in environments with drought stress by increasing the level of heterozygosity. This could be accomplished by developing synthetic varieties composed of germplasm with a high outcrossing rate. As a first step, we characterized the genetic structure of barley landraces and H. spontaneum populations collected from various semi-arid localities in Jordan to obtain reliable estimates of the amount and variation of outcrossing in this germplasm. Natural outcrossing was estimated in 13 populations of H. spontaneum and 12 barley landraces from collection sites that covered high-low transects for rainfall and altitude to detect possible environmental effects on outcrossing rate. Four microsatellite markers were used to estimate the outcrossing rate based on maximum likelihood methods and mixed mating models. Low outcrossing rates w...

Jordan Journal of Agricultural Sciences, 2010

Nine hundred and twenty lines of durum wheat landraces collected from ten locations in Jordan and... more Nine hundred and twenty lines of durum wheat landraces collected from ten locations in Jordan and seven checks (Haurani 27, Acsad 65, Om Qais, Sham 3, Sham1, Sham 5 and Deiralla 6) were evaluated under field conditions in two contrasting environments (semi-arid and arid conditions) on the basis of single head row progeny. The objectives were to estimate phenotypic (PCV) and genetic (GCV) coefficients of variation, broad sense heritability (h2)and genetic advance (GA) using the variance components method based on the combined analyses over locations and the variance analyses for each location for various agro-morphological and phenological traitsand to determine the interrelationships among these traits. Because of high genotype × location (G × L) interactions, estimates of GCV, h2 and GA for different traits using combined analysis were generally lower than the estimates computed from the variance analyses made separately for each location. The high cross-over G × L interactions cou...

This study aimed at investigating sources of tolerance in wheat and barley against the cereal lea... more This study aimed at investigating sources of tolerance in wheat and barley against the cereal leafminer, Syringopais temperatella Led. (Lepidoptera: Scythrididae) under semi-arid climate of Jordan. In this study, 546 accessions of bread and durum wheat, and barley were screened. The initial screening of the accessions was performed in 2006/2007, and accessions that displayed a type of resistance to S. temperatella in the initial screening were re-evaluated in 2008/2009. The average insect damage score (based on a 1 to 6 damage scale) in the initial screening was 5.1, 5.3 and 6.0 for barley, bread wheat and durum wheat, respectively. The percentages of barley and bread wheat accessions exhibiting resistance were 12.4% and 1.0%, respectively, while 4.1% and 11.0% of the accessions were tolerant. The re-evaluation of the selected barley and bread wheat accessions in 2008/2009 revealed that all the selected accessions were moderately tolerant with damage mean score of 2.5 to 4.3. Howeve...

Variation of twelve Hyoscyamus aureus, four H. desertorum and two H. reticulatus populations from... more Variation of twelve Hyoscyamus aureus, four H. desertorum and two H. reticulatus populations from Jordan were investigated at the phenotypic level with morphological characters and at DNA level using the Random Amplified Polymorphic DNA (RAPD) technique. Sixteen morphological traits were measured after 100 days from planting. There was a significant difference among the collected populations in 12 out of 16 morphological traits. The three highly polymorphic selected primers generated 60 RAPD bands with 39.5% mean level of the proportion of polymorphic loci. Multivariate procedures using dendograms and Principle Coordinate Analysis (PCoA) were used to classify the collected populations on the basis of phenotypic traits and RAPD fragments. RAPD estimate of genetic relationships among Hyoscyamus species was consistent with morphological study results. From the cluster analyses using dendograms and PCoA, it appears that morphological traits and RAPD markers were useful to separate the p...

The effects of water deficit and nitrogen (N) application were evaluated on dry matter (DM) and N... more The effects of water deficit and nitrogen (N) application were evaluated on dry matter (DM) and N remobilization in eight durum wheat varieties. Cham5, Cham3, Om Quis, Kayar Tunis and Hourani Nawawi had the highest DM remobilization under wetter environment ranging from 16.7 to 16.8%, rising to 20.7 to 23.7% in the drier environment. Cham 5 and Cham 3 also showed higher N translocation to grains (values=67.3 and 72.9%) under drier conditions. N deficiency significantly (P<0.05) increased N remobilization to grain in Deir Alla 6 and Hourani Nawawi; increasing N rate from 0 to 200 kg urea ha-1 decreased N remobilization from 40.8 to 20.8% and from 40.3 to 32.3% in Deir Alla 6 and Hourani Nawawi, respectively. In conclusion, some varieties showed high capacity for DM and N translocation under unfavorable conditions and they could be considered as a potential source of genes for plant breeding.

Jordan Journal of Agricultural Sciences, 2013

Genetic diversity and population structure of 20 durum wheat (Triticum turgidum L. subsp. durum) ... more Genetic diversity and population structure of 20 durum wheat (Triticum turgidum L. subsp. durum) landrace populations collected from three eco-agricultural zones from Jordan were studied; using Random Amplified Polymorphic DNA (RAPD) markers. DNA from ten individuals (i.e. lines) per population was analyzed using 21 RAPD primers. A total of 148 reproducible bands were detected, of which 128 (86.5%) were polymorphic. Nei’s genetic distance varied from 0.07 to 0.33. The unweighted pair-group method of arithmetic average (UPGMA) tree based on the genetic distance revealed that populations collected from northern and southern zones were grouped into two separate clusters in line with their putative geographic origins. Populations collected from the central zone were found mixed with populations collected from the two other zones, indicating that the villages located in the geographical center of the study area have a frequent exchange of seeds with other villages from northern and south...

Jordan Journal of Agricultural Sciences, 2013

This study was carried out to examine the response of 14 barley varieties to drought imposed at d... more This study was carried out to examine the response of 14 barley varieties to drought imposed at different developmental stages (DDS). To examine the effect of drought stress (DS) on germination rate and seedlings growth, the seeds were exposed to induced osmotic potentials (OP; -0.75 and -1.2 Mpa), in addition to the control. Er/Apm variety did not show any significant decrease in germination rate in response to OP. The most drought tolerant varieties at seedling stage were Morocco9-75, Yarmouk, Acsad 176, and WI2291 with minimal biomass losses. Varieties were also tested against four DS treatments: continuous DS (Dcon), early DS (Dearly), late DS (Dlate) and a combination of Dearly and Dlate (Dearly+late) treatments. Grain yield in the control treatment (continuous irrigation) was almost two times greater than Dcon treatment, while the reductions in Dearly, Dlate and Dearly+late treatments were 12.9, 26.1, and 33.6% compared to the control treatment, respectively. WI2291 and Yarmou...

JULY 2020

Populations of barley landrace [Hordeum vulgare (L.)] and wild barley progenitor [Hordeum spontan... more Populations of barley landrace [Hordeum vulgare (L.)] and wild barley progenitor [Hordeum spontaneum (L.)] were collected from 13 diverse eco-geographical regions in Jordan. In addition to two check varieties (Rum and Acsad 165) were collected from farmers’ fields. In total, 28 genotypes were evaluated during germination, early seedling and maturity stages for salt tolerance. Barley populations were exposed to tap water of 0.85 dS m-1 and saline solutions (NaCl, CaCl2 and MgSO4) of 4, 8, 12 and 16 dS m-1. Final germination percentage, the lengths of shoot and seminal root, growth and yield related traits were significantly decreased by increasing the level of salinity. Proline content was increased by increasing the level of salinity. A high level of salinity of 16 dS m-1 had a strong impact on reduction of grain yield and other agronomic traits in the examined populations. A considerable variation among populations was detectable. Barley landrace and wild barley that were collected...

Crop Research

Calcareous soil is extremely important in determining nutrient status and availability when apply... more Calcareous soil is extremely important in determining nutrient status and availability when applying different fertilizers to different crops associated with or without irrigation. The objective of this study was to investigate the nutritional status (nutrient availability) of different plants grown in two different ecosystems dominated with calcareous soil : Ghor Alsafi (eggplants, tomato and beans) as an example of irrigated area and the Karak Mountain Area (wheat) as an example for non-irrigated area. Physiochemical properties in soils and nutrients concentrations (C, Fe, Mn, Zn, available P, available and non-available K) in soil and plant leaves were analyzed. This study showed that N concentration in soil from both Ghor Alsafi (ranged from 4.4-5.1 mg/g) and the Karak Mountain Area (1.9-3.2 mg/g) was relatively low. This study showed that Fe content in vegetables grown in Ghor Alsafi was about 3 to 5 fold higher than the recommended maximum Fe concentration. The concentration of other nutrients (N, K, Zn and Mn) in investigated vegetables fell within the recommended concentrations range (38.3-39.7 mg/g, 36.6-39.5 mg/g, 21.7-27.3 ppm and 49.2-102.6 ppm, respectively). Phosphorus content in vegetables grown in Ghor Alsafi and in wheat grown in different locations in the Karak Mountain Area was about 5?6 fold higher than the recommended P concentration. Our results indicated that the high levels of P (ranged from 3.28-3.43 mg/g) and Fe (ranged from 340.4-551.3 ppm) in vegetables grown in Ghor Alsafi and high levels of P (ranged from 2.2-2.52 mg/g) in wheat in the Karak Mountain Area can be attributed to high levels of fertilizer application.

BMC Plant Biology

Background: Adaptation to drought-prone environments requires robust root architecture. Genotypes... more Background: Adaptation to drought-prone environments requires robust root architecture. Genotypes with a more vigorous root system have the potential to better adapt to soils with limited moisture content. However, root architecture is complex at both, phenotypic and genetic level. Customized mapping panels in combination with efficient screenings methods can resolve the underlying genetic factors of root traits. Results: A mapping panel of 233 spring barley genotypes was evaluated for root and shoot architecture traits under non-stress and osmotic stress. A genome-wide association study elucidated 65 involved genomic regions. Among them were 34 root-specific loci, eleven hotspots with associations to up to eight traits and twelve stressspecific loci. A list of candidate genes was established based on educated guess. Selected genes were tested for associated polymorphisms. By this, 14 genes were identified as promising candidates, ten remained suggestive and 15 were rejected. The data support the important role of flowering time genes, including HvPpd-H1, HvCry2, HvCO4 and HvPRR73. Moreover, seven root-related genes, HERK2, HvARF04, HvEXPB1, PIN5, PIN7, PME5 and WOX5 are confirmed as promising candidates. For the QTL with the highest allelic effect for root thickness and plant biomass a homologue of the Arabidopsis Trx-m3 was revealed as the most promising candidate. Conclusions: This study provides a catalogue of hotspots for seedling growth, root and stress-specific genomic regions along with candidate genes for future potential incorporation in breeding attempts for enhanced yield potential, particularly in drought-prone environments. Root architecture is under polygenic control. The co-localization of well-known major genes for barley development and flowering time with QTL hotspots highlights their importance for seedling growth. Association analysis revealed the involvement of HvPpd-H1 in the development of the root system. The co-localization of root QTL with HERK2, HvARF04, HvEXPB1, PIN5, PIN7, PME5 and WOX5 represents a starting point to explore the roles of these genes in barley. Accordingly, the genes HvHOX2, HsfA2b, HvHAK2, and Dhn9, known to be involved in abiotic stress response, were located within stress-specific QTL regions and await future validation.

Plant Breeding

This study aimed at developing, characterizing and evaluating two maize phenotypic-selected intro... more This study aimed at developing, characterizing and evaluating two maize phenotypic-selected introgression libraries for a collection of dominant plant height (PHT)-increasing alleles by introgressing donor chromosome segments (DCS) from Germplasm Enhancement of Maize (GEM) accessions into elite inbred lines: PHB47 and PHZ51. Different backcross generations (BC1-BC4) were developed and the tallest 23 phenotype-selected introgression families (PIFs) from each introgression library (PHB47 or PHZ51) were selected for single nucleotide polymorphism genotyping to localize DCS underlying PHT. The result shows that most PIFs carrying DCS were significantly (α = 0.01) taller than the respective recurrent parent. In addition, they contained larger donor genome proportions than expected in the absence of selection or random mating across all BC generations. The DCS were distributed over the whole genome, indicating a complex genetic nature underlying PHT. We conclude that our PIFs are enriched for favourable PHTincreasing alleles. These two libraries offer opportunities for future PHT gene isolation and allele characterization and for breeding purposes, such as novel cultivars for biofuel production.

Jordan Journal of Agricultural Sciences, 2014

Diversity among eight Jordanian snake melon (Cucumis melo var. flexuosus) landrace populations wa... more Diversity among eight Jordanian snake melon (Cucumis melo var. flexuosus) landrace populations was studied by analyzing morphological traits and random amplified polymorphic DNA (RAPD) markers. Pair-wise euclidean distances based on morphological data ranged from 4.6 to 8.10 among studied populations. Fruit traits explained the variation in the first two components (15.5% and 13.6% of the total variation were explained by PC1 and PC2 respectively), while the leaf traits were consistently present in the third component and therefore contributed less to the variability (10.8%). A total of 11 RAPD primers produced 85 fragments, of which 94% were polymorphic indicating a high degree of diversity. RAPD based dendrogram showed Nei's values ranging from 0.07 to 0.23 suggesting that the collected populations are genetically diverse. The range of gene diversity, (He) among snake melon populations ranged from 0.17 to 0.27. The analysis of molecular variance (AMOVA) showed that genetic variation among populations accounted for 18.52% of the total variation, while more than 80% occurred within populations consistent with outcrossing nature of snake melon. In conclusion, Jordanian snake melon landraces must be considered as a reservoir of genes that plant breeders need in their snake melon improvement programs.

Jordan Journal of Agricultural Sciences, Dec 30, 2013

This study was carried out to examine the response of 14 barley varieties to drought imposed at d... more This study was carried out to examine the response of 14 barley varieties to drought imposed at different developmental stages (DDS). To examine the effect of drought stress (DS) on germination rate and seedlings growth, the seeds were exposed to induced osmotic potentials (OP;-0.75 and-1.2 Mpa), in addition to the control. Er/Apm variety did not show any significant decrease in germination rate in response to OP. The most drought tolerant varieties at seedling stage were Morocco9-75, Yarmouk, Acsad 176, and WI2291 with minimal biomass losses. Varieties were also tested against four DS treatments: continuous DS (Dcon), early DS (Dearly), late DS (Dlate) and a combination of Dearly and Dlate (Dearly+late) treatments. Grain yield in the control treatment (continuous irrigation) was almost two times greater than Dcon treatment, while the reductions in Dearly, Dlate and Dearly+late treatments were 12.9, 26.1, and 33.6% compared to the control treatment, respectively. WI2291 and Yarmouk showed the minimal grain yield losses in response to DS at DDS and their ranks in response to DS remained almost unchanged at DDS, and consequently they could be considered as a potential source of genes for drought tolerance.

Jordan Journal of Agricultural Sciences, Mar 24, 2014

Diversity among eight Jordanian snake melon (Cucumis melo var. flexuosus) landrace populations wa... more Diversity among eight Jordanian snake melon (Cucumis melo var. flexuosus) landrace populations was studied by analyzing morphological traits and random amplified polymorphic DNA (RAPD) markers. Pair-wise euclidean distances based on morphological data ranged from 4.6 to 8.10 among studied populations. Fruit traits explained the variation in the first two components (15.5% and 13.6% of the total variation were explained by PC1 and PC2 respectively), while the leaf traits were consistently present in the third component and therefore contributed less to the variability (10.8%). A total of 11 RAPD primers produced 85 fragments, of which 94% were polymorphic indicating a high degree of diversity. RAPD based dendrogram showed Nei's values ranging from 0.07 to 0.23 suggesting that the collected populations are genetically diverse. The range of gene diversity, (He) among snake melon populations ranged from 0.17 to 0.27. The analysis of molecular variance (AMOVA) showed that genetic variation among populations accounted for 18.52% of the total variation, while more than 80% occurred within populations consistent with outcrossing nature of snake melon. In conclusion, Jordanian snake melon landraces must be considered as a reservoir of genes that plant breeders need in their snake melon improvement programs.