Habib Khemira

Obesity and its associated health complications, including diabetes, cardiometabolic impairments, disability, and various forms of cancer, have reached epidemic levels, highlighting the global impo...

In Saudi Arabia, coffee (Coffea arabica L.) has been grown for centuries on the mountain terraces of the southwestern regions. Jazan region accounts for about 80% of the total production. The acreage allocated to coffee is comparatively small but it is expanding rapidly thanks to a strong government-supported drive to increase local coffee production. Despite the initial success, the effort is hampered by the limited water supply available for irrigating the new plantings and the increased incidence of pests and diseases. The magnitude of these natural handicaps appears to have increased as of late, apparently due to climate change (CC). This review examines strategies to mitigate the consequences of CC on the coffee sector through the implementation of precision agriculture (PA) techniques, with the focus on addressing the challenges posed by biotic and abiotic stresses. The impact of CC is both direct by rendering present growing regions unsuitable and indirect by amplifying the severity of biotic and abiotic tree stressors. Precision agriculture (PA) techniques can play a key role in tackling these challenges through data-driven tools like sensors, GIS, remote sensing, machine learning and smart equipment. By monitoring soil, climate, and crop conditions, PA enables targeted irrigation, fertilization, and pest control thus improving efficiency and sustainability. This approach reduces costs, conserves resources, and minimizes environmental impact, making PA essential for building climate-resilient and sustainable coffee production systems. The review synthesizes insights from case studies, research papers, and other scientific literature concerned with precision farming practices and their effectiveness in alleviating biotic and abiotic pressures on coffee trees. Additionally, it evaluates technological advances, identifies existing knowledge gaps, and suggests areas for future research. Ultimately, this study seeks to contribute to enhancing the resilience of coffee farming in Saudi Arabia amidst ongoing CC challenges by educating farmers about the potential of PA technologies.

Guar (Cyamopsis tetragonoloba L. Taub.) is a significant summer legume used as food for both humans and livestock. In Saudi Arabia, the root nodule bacteria of guar have not been studied. The present work investigated the phenotypic and genetic diversity of guar microsymbionts. Eighty-eight bacterial strains were isolated from the root nodules of guar grown in different locations of Jazan region of Saudi Arabia. The strains were analyzed based on their phenotypic characteristics and variations in their 16S rRNA gene sequences. A significant proportion of the isolates (90%) were fast-growing rhizobia, with 77% showing tolerance to 3–4% NaCl and 91% capable of thriving at temperatures reaching 40 °C. Several isolates exhibited strong plant growth-promoting traits, particularly in IAA production and phosphate solubilization. Genetic analysis indicated considerable diversity, with isolates classified under the genera Rhizobium, Ensifer, Mesorhizobium, Bradyrhizobium, and Agrobacterium. To the best of our knowledge, this study is the first to report on the phenotypic and genetic diversity of guar microsymbionts in Saudi Arabia.

Coffee (Coffea arabica L.) is one of the most important agricultural commodities traded worldwide. The livelihoods of millions of households in Asia, Africa and America depend on it. The sustainability of the supply chain of this crop is increasingly under threat due to the impact of climate change in the main producing countries in the tropics and sub-tropics. The resilience of these agro-ecosystems will depend on the ability of breeders to develop new coffee varieties that can better adapt to changing environmental conditions. Therefore, studying the diversity of coffee populations in the Arabian Peninsula could reveal agronomically interesting genotypes that can be exploited in breeding programs. The objective of the study was to evaluate the diversity among coffee populations in southwestern Saudi Arabia using quantitative morphological, pomological and agronomic traits. The analysis of variance of the data showed differences among the accessions for most of the measured quantitative traits. The accessions varied in growth habit, canopy shape and cherry, bean and leaf dimensions. Cherry fresh mass ranged from 96.5 to 234.8 g in 100 cherries while 100-bean dry mass varied from 9.3 to 22.5 g. The hierarchical cluster analysis divided the accessions into four main groups. The study revealed considerable variability among the 61 accessions. Based on this investigation, accessions KSA-7R, KSA-8 and KSA-9R from Tallan valley, KSA20, KSA21 and KSA52 from Fayfa, KSA38 from Eddayar district, KSA10 and KSA60 from Assir region and KSA61 from Jebel Shada are recommended for further investigation for their promising agronomic traits.

The genetic diversity of local coffee populations is crucial to breed new varieties better adapted to the increasingly stressful environment due to climate change and evolving consumer preferences. Unfortunately, local coffee germplasm conservation and genetic assessment have not received much attention. Molecular tools offer substantial benefits in identifying and selecting new cultivars or clones suitable for sustainable commercial utilization. New annotation methods, such as chloroplast barcoding, are necessary to produce accurate and high-quality phylogenetic analyses. This study used DNA barcoding techniques to examine the genetic relationships among fifty-six accessions collected from the southwestern part of Saudi Arabia. PCR amplification and sequence characterization were used to investigate the effectiveness of four barcoding loci: atpB-rbcl, trnL-trnF, trnT-trnL, and trnL. The maximum nucleotide sites, nucleotide diversity, and an average number of nucleotide differences were recorded for atpB-rbcl, while trnT-trnL had the highest variable polymorphic sites, segregating sites, and haploid diversity. Among the four barcode loci, trnT-trnL recorded the highest singleton variable sites, while trnL recorded the highest parsimony information sites. Furthermore, the phylogenetic analysis clustered the Coffea arabica genotypes into four different groups, with three genotypes (KSA31, KSA38, and KSA46) found to be the most divergent genotypes standing alone in the cluster and remained apart during the analysis. The study demonstrates the presence of considerable diversity among coffee populations in Saudi Arabia. Furthermore, it also shows that DNA barcoding is an effective technique for identifying local coffee genotypes, with potential applications in coffee conservation and breeding efforts.

Salt stress is a sever threat to global agriculture. Improving salt tolerance is a problematic task due to the large number of characteristics involved. Graft technique is a potential substitute to breeding and interesting practices to salt tolerance since it unites a scion and rootstock of two genotypes. Increased salinity tolerance in fruit trees will alter water relations, disrupt ionic balance, which can harm plant tissues and thus limit plant productivity. Therefore, the ability of fruit trees to resist salinity varies by species, although it is mostly determined by the type of their root systems. In this regard, the selection of salt-tolerant rootstocks can help maintain productivity under salinity. Several physiological and biochemical changes are attributed to the favorable response of grafting exerted by tolerant rootstocks or scion-rootstock interactions on yield and fruit attributes of plants in saline environments. Rootstocks provide grafted plants different salt tolerance mechanisms including the accumulation of compatible solutes and enhancing the antioxidant mechanisms in scion. The importance of grafting, strategies for selecting appropriate rootstocks, scion-rootstock interaction for growth and the tolerance mechanisms used by plants to avoid the effects of salt stress, are all discussed in this review. Grafting’s potential challenges are also discussed.

Thermal springs have hydrothermal or volcanic activity, which causes the water to boil up and dissolve any metal that may be present there. It helps in recovery to reduce stress, promote sleep, boost blood circulation, relieve pain and heal skin problems. However, they consist of some heavy and trace metals and some non-metals, such as Mg, Mo, Na, As, Hg, Cd, Ni, Fe, Cu, Mn, Zn, Co, Ti, Cr and Pb are present. These hot springs are also known to exhibit natural microbiota, which is helpful in maintaining the public health and preventing consumer outbreaks with the advancement of research, microbiological monitoring of hot spring water can be done by utilizing high throughput sequencing. Taking these facts in concern, the present work, hot spring samples were collected from different locations of Al-Harth and Alarda hot springs, Jazan region, Saudi Arabia. The samples collected were analyzed for trace minerals and microbiological activity. These samples were found to exhibit the temperature range from 60 to 70 ºC and an average pH of 6.5 to 8.5. Almost all the samples had shown the presence of trace elements with electrical conductivity and total dissolved solids (TDS) ranged from 0.02 to 0.045 dms and 27 to 43 mg/L, respectively. Scattergun metagenomic analysis was performed to determine the microbiological content. The preliminary study reports the microbiome (bacteria, archea and viruses) of alarath hot spring water employing whole-genome high-throughput sequencing and bioinformatics. Bacterial species detected were members of the phyla 64% Proteobacteria, 20% Actinobacteria, 6.3% unclassified, 2.2% Deinococcus thermus, 1.4 Firmcutes and 1.6% others. Fecal indicator bacteria, i.e. Escherichia coli or enterococci, were not detected in any samples examined in this study. Both archaeal DNA (0.4%) and viral DNA (0.009%) were found.

The genetic diversity of local coffee populations is crucial to breed new varieties better adapted to the increasingly stressful environment due to climate change and the evolving consumer preferences. Unfortunately, local coffee germplasm conservation and genetic assessment have not received much attention. Molecular tools offer substantial benefits in identifying and selecting new cultivars or clones suitable for sustainable commercial utilization. New annotation methods, such as chloroplast barcoding, are necessary to produce accurate and high-quality phylogenetic analyses. This study used DNA barcoding techniques to examine the genetic relationships among fifty-six accessions collected from the southern part of Saudi Arabia. PCR amplification and sequence characterization were used to investigate the effectiveness of four barcoding loci, namely atpB-rbcl, TrnL-TrnF, TrnT-TrnL, and TrnL. The maximum nucleotide sites, nucleotide diversity, and an average number of nucleotide differences were recorded for atpB-rbcl, while TrnT-TrnL had the highest variable polymorphic sites, segregating sites, and haploid diversity. Among the four barcode loci, TrnT-TrnL recorded the highest singleton variable sites, while TrnL recorded the highest parsimony information sites. Furthermore, the phylogenetic analysis clustered the Coffea arabica genotypes into four different groups, with three genotypes (KSA31, KSA38, and KSA46) found to be the most divergent genotypes standing alone in the cluster and remained apart during the analysis. The study demonstrates the presence of considerable diversity among coffee populations in Saudi Arabia. Furthermore, it also shows that DNA barcoding is an effective technique for identifying local coffee genotypes, with potential applications in coffee conservation and breeding efforts.

Coffea arabica, a member of the Rubiaceae family, is the most commercially important species of the genus Coffea. It has been grown on the mountain terraces of southwestern Saudi Arabia for centuries. At present, the species is subject to increased genetic erosion due to the abandonment of many gardens by their owners and the increasingly dry climate. The current study was carried out to determine the genetic diversity of 56 local coffee accessions collected from the southern regions of Saudi Arabia using 30 sequence-related amplified polymorphism (SRAP) markers. Six SRAP markers showed polymorphism among the 56 accessions. A total of 1125 bands, with an average of 187.5, was produced from all six SRAP primers. The polymorphic information content (PIC) ranged from 74.8 to 97.7, with an average of 91.4 for all studied SRAP markers. The high polymorphism percentage seen in this study, along with the high number of alleles produced and the high PIC values of the primers used, demonstrate that the SRAP approach was an effective molecular technique for assessing genetic diversity in the studied populations. The structural analysis showed a sharp peak, with no ambiguity, demonstrating the highest delta K value at K = 3 and K = 6, and the coffee accessions could be grouped into three and six main populations, respectively. The PCoA, cluster analysis, and structural population analysis results suggest considerable genetic diversity among coffee populations growing on the southwestern mountain terraces of Saudi Arabia. The 56 accessions were segregated into five groups, mostly according to geographic distribution. The accessions from the southern districts of Jazan region mostly clustered in groups 2 and 4, while the accessions from the northern districts of Al-Baha and Assir regions formed separate groups. Based on these analyses, accessions KSA1R, KSA6R, KSA21, KSA25, KSA37, KSA38, KSA42, KSA59, KSA60, KSA62, and KSA63 were the most divergent. The genotypes should be conserved for use in coffee-breeding programs to improve the agronomic value of the crop, broaden the genetic base of C. arabica in Saudi Arabia and increase environmental resilience. Additional molecular and functional genomics studies are necessary to further elucidate how this germplasm has evolved and enhance the value of local Arabica coffee diversity in the Kingdom.