تأثير بعض عوامل المقاومة الأحيائية و الكيميائية في مكافحة مرض موت البادرات و تعفن جذور نبات الباذنجان (Solanum melongena) في محافظة كربلاء

Effect of Some Biotic and Abiotic Factors in Controlling Seedling Damping-Off and Root Rot Disease of Eggplant (Solanum melongena) in Karbala Governorate

Abstrac
This study was conducted at the College of Agriculture – University of Karbala with the aim of diagnosing the fungi causing seedling death and root rot of eggplant Solanum melongena in a number of farms in Karbala Governorate and testing their pathogenicity and testing the response of a number of eggplant hybrids and testing the family range and testing the antagonistic ability of a number of biological factors and the chemical pesticide Beltanol and Melatonin in controlling the most pathogenic fungus causing the disease in the laboratory and under greenhouse conditions..
The isolation and diagnosis results showed that 73 isolates were obtained, 30 of which were Fusarium solani, 18 of Rhizoctonia spp., 14 of Fusarium oxysporum, 10 of Macrophomina phaseolina and one of Rhizopus arrhizus. The isolate was diagnosed morphologically and F. solani was superior in its appearance rate, which reached 44.00%. and laboratory pathogenicity results showed superiority of the isolates, Rh5, Rh10, Rh13, Rh17, Fs4, Fs6, Fs12, Fs16, Fs17, Fs19, Fs28, Fo2, Fo5, Fo6, Fo12, Fo13, Fo14, Mp2, Mp3. , Mp5, Mp10, Mp11 were significant (P>0.05) in reducing the percentage of eggplant seed germination On the W.A culture medium, the percentage germination rate reached 0.0%, and the isolate Fs4 (F.solani) excelled in giving the highest percentage of infecting eggplant seedlings in plastic pots under greenhouse conditions, as it reached 100%.
The results of the molecular diagnosis of the most pathogenic isolate were revealed by analyzing the sequences of the nitrogenous bases of the DNA products amplified by polymerase chain reaction (PCR-amylified products) for the selected genetic markers and using the BLAST program (Basic Local Alignment Search Tool) This isolate belongs to the fungus F. solani. The results also demonstrated that there was a degree of discrepancy between the isolates identified molecularly in this study and the isolates previously diagnosed and confirmed at the National Center for Biotechnology Information (NCBI), so these isolates were registered at the aforementioned center under the accession number PP467610.1. PP467604.1, PP46703.1, PP467609.1,PP467611.1 For fungal isolates F. oxysporum, F.solani2, F.solani3, M. phaseolina and Rhizopus arrhizus, respectively.
The results of the response of a number of eggplant hybrids to infection with root rot showed that the Champion variety was the most susceptible variety, with an infection rate of 100% compared to the healthy control treatment, in which it was 0.0%. The results of the family range test showed that the most pathogenic isolate of the fungus F. solani was susceptible to infecting pepper, eggplant and tomato and did not affect the germination of okra seeds. Watermelon, cucumber, cowpeas and squash, and a test of the antagonistic ability of the biological agent Trichoderma koningiopsis on PDA culture medium showed that an inhibition rate of the fungus F.solani reached 97.77%. The chemical pesticide Beltanol was superior to the pesticide Mechazol by achieving an inhibition rate of the pathogenic fungus in the PDA culture medium that reached 100% for all concentrations used in While this pesticide did not show a significant effect (P > 0.05) on the T. koningiopsis fungus used as a biological control agent, a concentration of 1.5 melatonin gave the best inhibition of the pathogenic fungus, amounting to 94.40%.
The integration treatment between all biological and chemical factors (F.s14+Biohealth+Melatonin Trichoderma koningiopsis+ +Beltanol) used in the study was significantly (P>0.05) superior to the other treatments in reducing the percentage and severity of infection with the fungus F.solani in plastic pots and in the soil of the greenhouse. When I reached 0.0% The same treatment was superior in increasing the dry weight of the shoot and root systems and increasing the root volume in the presence of the pathogen, as it reached 9.00 g, 3.00 g, and 50.31 ml, respectively, compared to the treatment of the pathogenic fungus alone, which amounted to 0.132 g, 0.002 g, and 0.01 ml, respectively. The combination treatment excelled among all the factors used in increasing the levels of total phenols and peroxidase enzyme, reaching 0.921 mg/g, 74.31 (units.g, wet weight), respectively, compared to the treatment of the pathogenic fungus alone, which amounted to 0.533 mg/g, 33.08 (units.g, wet weight). )respectively.