Publications by authors named "Mahmoud H El Komy"
Recently, Saudi growers have expanded their production of organic, soilless-grown strawberries (Fragaria × ananassa Duch.), but their production shows many difficulties associated with disease susceptibility. In October 2021, 45% of strawberry plants cv.
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- Gray mold disease, caused by the fungus Botrytis cinerea, is a significant threat to fruits like strawberries and tomatoes, prompting research on using Bacillus spp. volatile organic compounds (VOCs) as eco-friendly biocontrol agents.
- In vitro tests showed that VOCs from Bacillus sp. LNXM12 were the most effective, inhibiting fungal growth by 61.2% and demonstrating a higher control efficacy on infected fruits compared to other strains.
- Further analysis identified 22 VOCs, with synthetic compounds ethyloctynol and 3-methyl-2-pentanone (3M2P) showing strong inhibition of fungal growth and downregulating virulence genes in B. cinerea
Article Synopsis
- Citrus greening disease was first identified in Saudi Arabia in the 1970s, but the bacteria 'Liberibacter asiaticus' (CLas) was only confirmed in the early 1980s through microscopy.
- A recent survey of 13 citrus-growing regions in Saudi Arabia aimed to assess the presence of CLas and its vector, the Asian citrus psyllid (ACP), finding evidence of CLas in 10 regions, but no CLas detected in the psyllids themselves.
- Phylogenetic analysis revealed that the Saudi isolates of CLas are closely related to those from Florida, and climate data suggest that the environmental conditions in Saudi Arabia align with areas conducive to the disease's establishment.
Article Synopsis
- Huanglongbing (HLB), or citrus greening, is a severe disease affecting citrus crops worldwide, and currently, there is no effective cure, making early control essential.
- This study focused on the effects of salicylic acid (SA) and phenylacetic acid (PAA) treatments on young citrus seedlings to determine their effectiveness against HLB, revealing significant reductions in disease severity and bacterial levels when combined with Oxytetracycline (OTC).
- Results indicated that treated plants showed increased defense mechanisms and that the use of SA and PAA could be a promising and environmentally friendly strategy for managing HLB in citrus seedlings.
Article Synopsis
- Coffee production in Saudi Arabia is being affected by anthracnose disease, with a 55% incidence observed in affected trees in Jazan Province as of December 2021.
- Symptoms included dieback, necrotic leaves, and dark lesions on berries that ultimately mummified.
- Pathogen isolation from diseased samples led to the recovery of two isolates identified as Colletotrichum gloeosporioides, with their genomic DNA analyzed for further identification.
Article Synopsis
- Onion crops in Saudi Arabia experienced significant health issues in late 2020, with symptoms such as wilting and bulb rot affecting 30-65% of plants in the surveyed fields.
- The pathogen was identified as Fusarium oxysporum through a series of laboratory tests, including sanitization of diseased plant tissues and culturing on specific media that revealed characteristic fungal growth.
- Further confirmation of the pathogen's identity involved DNA extraction and sequencing of various nuclear regions, contributing to the understanding of its genetic makeup and potential impacts on onion cultivation.
Characterization of the Asian Citrus Psyllid-' Liberibacter Asiaticus' Pathosystem in Saudi Arabia Reveals Two Predominant CLas Lineages and One Asian Citrus Psyllid Vector Haplotype.
Microorganisms
October 2022
Article Synopsis
- The citrus greening disease in Saudi Arabia is caused by the bacterium 'Liberibacter asiaticus' and spread by the Asian citrus psyllid (ACP), with limited prior research on its invasion origin and routes in the region.
- Adult ACP were analyzed using mitochondrial and nuclear genes to identify and differentiate their genetic makeup, revealing a dominant haplotype linked to populations from the Indian subcontinent.
- The study also employed polymerase chain reaction (PCR) to detect CLas in citrus trees and sequenced prophage genomes, uncovering two major CLas lineages, with the findings shedding light on the co-evolution and global spread of the ACP-CLas system, with origins traced back to South and Southeast Asia
Article Synopsis
- Mango trees in Saudi Arabia are facing serious problems because of diseases that hurt their growth and production.
- In December 2021, a survey showed that about 40% of mango trees in Al-Jumum had symptoms like dying twigs and falling leaves.
- Researchers collected 20 sick branches to study the disease, finding a fungus that could be causing these issues by looking at how it grows and what it looks like.
Several species of Fusarium cause serious diseases in date palm worldwide. In the present work, 14 SSR markers were used to assess the genetic variation of Fusarium strains isolated from diseased trees in Saudi Arabia. We also studied the effect of different temperatures on mycelial growth of these strains.
View Article and Find Full Text PDFCucumber (Cucumis sativus L.) is an important vegetable crop in Saudi Arabia. During May 2018, 45 - 60% of 5-month-old cucumber plants showed symptoms of a previously unknown wilt in commercial greenhouses around Al Kharj area of Riyadh region.
View Article and Find Full Text PDFBackground: Terrestrial mollusks are one of most important agricultural pests worldwide. Natural phytochemicals have an extended history as a source of pesticides. This study was planned to isolate molluscicidal active compounds from the stems of Adenium obesum.
View Article and Find Full Text PDFBayoud disease, caused by Fusarium oxysporum f. sp. albedinis, is a very serious and destructive disease to date palm.
View Article and Find Full Text PDFThe use of novel isolates of Trichoderma with efficient antagonistic capacity against Fusarium oxysporum f. sp. lycopersici (FOL) is a promising alternative strategy to pesticides for tomato wilt management.
View Article and Find Full Text PDFIn this study, resistance responses were investigated during the interaction of Botrytis fabae with two faba bean cultivars expressing different levels of resistance against this pathogen, Nubaria (resistant) and Giza 40 (susceptible). Disease severity was assessed on leaves using a rating scale from 1 to 9. Accumulation levels of reactive oxygen species (ROS), lipid peroxidation and antioxidant enzymes (superoxide dismutase, catalase and ascorbate peroxidase) were measured in leaf tissues at different times of infection.
View Article and Find Full Text PDFRAPD polymerase chain reaction analysis was used to study the genetic diversity among a wild potato variety Solanum demissum (very resistant to late blight) and six potato cultivars (Hanna, Lady-Olympia, Lady-Rosetta, Spunta, Diamant and Cara) varied in their resistance to Phytophthora infestans. Cluster analysis of six potato genotypes showed that, all tested genotypes were separated into two clusters (1 and 2). Cluster 1, included only the wild potato variety (S.
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