Document Details

Document Type : Thesis 
Document Title :
Effect of Leaf and Seed Extracts of Neem (Azadirachta Indica .A. Juss) on The Growth and Pathogencity of Some Plant Pathogenic Fungi
تأثير مستخلصات أوراق وبذور النيم على النمو والقدرة الإمراضية لبعض الفطريات الممرضة للنبات
 
Subject : Biological 
Document Language : Arabic 
Abstract : Three lab experiments were conducted in the Dep. of Arid land Agric., Faculty of meteorology, Environment and Arid Land Culture, King Abdulaziz Univ. to study the linear growth, spore germination and pathogenicity of some plant pathogenic fungi under for the first second experimental the effect of aqueous and ethanolic extracts of the neem leaves and seeds. The aqueous and ethanolic extracts at the concentrations 1:1, 1:10, 1:100 and 1:1000 were studied on the linear growth and spore germination of Alternaria alternate, Pythium aphanidermatum, Helminthosporium spp., Fusarium oxysporium, Bipolaris sorokiniana and Thilaeviobsis sp. The effect of the extracts at the ratio 1:1 were also studied on the pathogenicity of P. aphanidermatum, causing damping off on cucumber seedlings from 8-48 hrs. The main results for the first experiment revealed that the ethanolic extract of the neem seeds had the best effect followed by the ethanolic leaf extract then the aqueous seed extract on the linear growth of the following fungi: Alternaria alternate, Pythium aphanidermatum, Helminthosporium spp. and Bipolaris sorokiniana. On the other hand better suppression of the growth of Thilaeviobsis sp was obtained when the aqueous seed extract was used compared to either the ethanolic seed or leaf extracts. Linear growth Fusarium oxysporium, however, was not significantly affected by any of the tested extracts. No effect was detected of the aqueous leaf extract on any tested fungus in this experiment. In the second Experimental when the three extracts were tested on the germination of the selected fungi, the aqueous followed by the ethanolic seed extract showed the best results on Alternaria alternate, Pythium aphanidermatum, Helminthosporium spp., Fusarium oxysporium The least effect was determined when the ethanolic leaf extract was used on the germination of fungal spores. Spore germination of Thilaeviobsis sp was mostly affected by the ethanolic leaf extract followed by the aqueous seed extract and the least effective was the ethanolic seed extract. Bipolaris sorokiniana spore germination was not affected significantly by any of the tested extracts. The results of the effect of concentration revealed the concentration (1 : 1) gave the best effect for growth and spone generation of different fungi. following the other concentration. In the third experiment, pathogenicity of the fungus P. aphanidermatum was mostly affected by the aqueous followed by the ethanolic seed extracts then the ethanolic leaf extract where 42.66, 43.7 and 52.86% of the cucumber seedlings were infected by the pathogen as compared to % of the control seedlings. Concerning seedling infection through time it was of ovious that the infection rate incnaus through time from 8 h (0%) to 48 h (81.33%). 
Supervisor : Prof. Fahad Abdulrahman Alfassi 
Thesis Type : Master Thesis 
Publishing Year : 1428 AH
2007 AD
 
Co-Supervisor : Prof. Yahya Hamza Sonbol 
Added Date : Tuesday, June 10, 2008 

Researchers

Researcher Name (Arabic)Researcher Name (English)Researcher TypeDr GradeEmail
رعد حمود الحازميal-Hazmi, Raad HamoudResearcherMaster 

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