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RESEARCH

Pathological Characterization and Management of Lasiodiplodia theobromae, a Hemibiotroph with an Interkingdom Host Range

    Affiliations
    Authors and Affiliations
    • Osama O. Atallah1
    • Abdallah A. Hassanin2
    • Sherin M. Yassin3
    • Abeer S. Aloufi4
    • Enas A. Almanzalawi5
    • Ahmed Abdelkhalek6
    • Mahmoud M. Atia1
    • Said Behiry7
    • Abdelrazek S. Abdelrhim8 9
    • Yasser Nehela10
    1. 1Department of Plant Pathology, Faculty of Agriculture, Zagazig University, Zagazig, Egypt
    2. 2Genetics Department, Faculty of Agriculture, Zagazig University, Zagazig, Egypt
    3. 3Plant Pathology Research Institute, Agriculture Research Center, Giza, Egypt
    4. 4Department of Biology, College of Science, Princess Nourah bint Abdulrahman University, Riyadh 11671, Saudi Arabia
    5. 5Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
    6. 6Plant Protection and Biomolecular Diagnosis Department, New Borg El Arab City, Alexandria, Egypt
    7. 7Agricultural Botany Department, Faculty of Agriculture (Saba Basha), Alexandria University, Alexandria, Egypt
    8. 8Department of Plant Pathology, Faculty of Agriculture, Minia University, Minia, Egypt
    9. 9Department of Plant, Soil and Microbial Sciences, College of Agriculture & Natural Resources, Michigan State University, East Lansing, MI 48824, U.S.A.
    10. 10Department of Agricultural Botany, Faculty of Agriculture, Tanta University, Tanta, Egypt

    Published Online:https://doi.org/10.1094/PDIS-03-24-0713-RE

    Heart rot disease, caused by Lasiodiplodia theobromae, is destructive for date palms and other woody plants. The disease was reported in several oases in Egypt, and the pathogen was found in association with infected trees suffering dieback and rachis blight. Seven phylogenetically distinct fungal isolates were selected, and their pathogenicity was confirmed on date palms. The isolates exhibited variable degrees of virulence on inoculated leaves, which confirms the variation. We examined the antifungal effect of microbial bioagents and plant extracts on heart rot disease. The isolates of Trichoderma spp. gave moderate reduction of the pathogen’s linear growth (40 to 60%), whereas their exudates were ultimately ineffective. Bacillus spp. isolates, except for B. megaterium, were more effective against spore germination, giving 80 to 90% reduction on average. Among the examined plant extracts, garlic sap gave 98.67% reduction of linear growth followed by artemisia (15.5%) and camphor (24.8%). The extraction methods greatly influenced the antifungal efficiency of each extract because exposure to organic solvents significantly decreased the efficiency of all extracts, whereas hot water extraction negatively affected garlic sap only. Successful bioagents and plant extracts were further assayed for the suppression of heart rot disease on date palms. Both T. album and T. harzianum gave comparable degrees of suppression as by commercial fungicides. In addition, treatment before or during pathogen inoculation was the most effective because it significantly enhanced the expression of defense-related enzymes. Our findings suggest biopesticides possess a dual role in disease suppression and defense boosters for date palms suffering heart rot disease.

    Literature Cited