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Rot disease is responsible for serious economic losses related to okra (Abelmoschus esculentus) crops cultivated in Upper Egypt. Colonies with a consistent morphology were isolated from the infected okra stems and leaves and subjected to morphological and molecular examinations. The causal pathogen was identified as Cochliobolus spicifer based on morphological fungus descriptions, as well as on the amplified 28S rDNA and internal transcribed spacer region (ITS) sequences, which showed 99%–100% similarity to the sequences of C. spicifer - CSN-20 strains. The volatile and non-volatile organic compounds (VOCs and n-VOCs, respectively) produced by the endophytic fungi that are associated with the medicinal plant Solenostemma arghel , namely Fusarium solani -F4-1007, Penicillium verrucosum -F2-1006, and Aspergillus terreus -F5-1008, inhibited the growth of the C. spicifer pathogen by 34.2%,31.4%, and 30.5%, respectively. In total,27 VOCs were identified by GC/MS, among which eight were specific to A. terreus -F5-1008, eight to P. verrucosum -F2-1006, and three to F. solani -F4-1007, whereas nine VOCs were commonly produced by the three endophytic fungi. Moreover, F. solani -F4-1007-produced VOCs and n-VOCs exhibited the highest antifungal activity, with 37.27% and 37.1% inhibition against C. spicifer colony growth, respectively. The potent antifungal VOCs produced by F. solani -F4-1007 were identified as 3,4-dihydro-2 h-1,5-(3″-t-butyl) benzodioxepine, 4-(2-hydroxyethyl) phenol, and phenylethyl alcohol using GC/MS. Therefore, F. solani -F4-1007 was tested as a potential biocontrol agent against C. spicifer- CSN-20 using an in-planta assay. Okra plants treated with endophytic F. solani -F4-1007did not show any disease symptoms, whereas those that were not treated with F. solani -F4-1007 exhibited severe disease symptoms when challenged with inoculation of the C. spicifer pathogen. Our results demonstrated the contribution of the endophytic fungus F. solani -F4-1007 as a potential biocontrol agent against the C. spicifer pathogen, to improve okra growth. [ABSTRACT FROM AUTHOR]

Tomato (Solanum lycopersicum L.) is an important worldwide vegetable crop. This paramount crop would be infected by a serious set of pathogenic fungal diseases. Growth and production are hampered by early blight caused by Alternaria phragmospora. In vitro the production of growth promoted hormone indole acetic acid (IAA) by Aspergillus flavus isolated from the medicinal plant, Euphorbia geniculata was stimulated in culture media supplemented or not by tryptophan (120 and 40 μg mL−1) respectively. The blue fluorescence test showed that the endophytic A. flavus was lacking to produce aflatoxins. Inoculation of S. lycopersicum with A. flavus enhanced the fresh weight (FW) and plant length (PL) of S. lycopersicum significantly in comparison to untreated plants. The PL of treated plants was 39.05 cm ± 3.16, while control was 22.19 cm ± 4.54. IAA stimulated overproduction of lateral roots and root hairs in treated plants compared to control. After spraying with A. phragmospora , the treated plant with A. flavus showed healthy leaves and completely protected (100%) from the disease symptoms. There were significant increases in chlorophyll (1.68 mg g−1 FW), flavonoids (105.4 mg g−1 dry weight), carbohydrates (155.5 mg g−1 dry weight), phenolics (0.9 mg g−1 dry weight) and total proteins contents (94.13 mg g−1 dry weight) in treated plants relative to untreated control plants. Our findings demonstrated the contribution of A. flavus to improve the growth and the secondary metabolites contents of tomato, which subsequently leads to the improvement of the resistance of this plant to an aggressive plant pathogen like A. phragmospora. [ABSTRACT FROM AUTHOR]