ملخص البحث :

Abstract: This study was conducted in plant pathology laboratory and lath house of Department of Plant ProductionTechniques, Technical Institute of Kufa, Al-Furat Al-Awsat Technical University to isolate and identify fungi that associatedwith Citrus seedlings roots and improve its growth by using some organic extracts. Results showed that many fungi isolatedfrom citrus seedlings roots as the species Fusarium solani achieved highest percentage of frequency and prevalence 90.91and 43.01% respectively among all isolated fungi, while, Arthrinium phaeospermum, Cladosporium sphaerospermum andPenicillium italicum recorded the lowest frequency and prevalence amounted 4.55 and 1.08% respectively. The effect ofsome organic extracts and captin pesticide on the growth of F. solani and vegetative indicators of Narang was studied and theresults indicated that captin was more effective in controlling the pathogenic fungus by inhibiting its growth to 0 cm followedby humic acid 5.4 cm and humic acid ground 7.1 cm in comparison with 8.5 cm in control treatment. Foliar humic acidsignificantly increased all studied traits but F. solani + captin recorded the lowest vegetative indicators as compared topositive and negative controls.

ملخص البحث :

Abstract: The study was aimed to reduce in the percentage of infection and its severity of black blight disease in palmseedlings by using the spore suspension of some biological control agents. P.fluorescens bacteria was superior on the otherbiological control agents in reducing the percentage and severity of infection. It reduced in values to 2, 1.5%, respectivelywhile B.subtilis was given values 4, 3.5%, respectively. The T.harzianum fungus was given effect less than 9, 6.5%, respectivelyin comparison with the control which was given values 36, 13.8%, respectively. Biocontrol agents were tested against thepathogen T. Paradoxa fungus, with a value of 1.0 according to the five-point standardization scale which was prepared byBell et al. (1982). The P.fluorescene showed an inhibitory capacity of 76% while the B. subtilis bacterium showed inhibitorycapacity of 67%. The effect of environmental control factors on the growth of the pathogen T.Paradoxa was studied inlaboratory. All the filtrate concentrations of the biological factors were superior in growth reducing of the pathogen funguscompared to the control, the filtration of the fungus T.harzianum was superior in all concentrations by reducing of pathogenfungus growth, while the concentrations of B.subtilis were the least affected in reducing the growth of pathogen fungus.

ملخص البحث :

ملخص البحث :

Abstract This study was conducted at the Agriculture College University of Karbala, Iraq to isolate and morphologically and molecularly diagnose thirteen Cladosporium isolates collected from tomato plant residues present in desert regions of Najaf and Karbala provinces, Iraq. We diagnosed the obtained isolates by PCR amplification using the ITS1 and ITS4 universal primer pair followed by sequencing. PCR amplification and analysis of nucleotide sequences using the BLAST program showed that all isolated fungi belong to Cladosporium sphaerospermum. Analysis of the nucleotide sequences of the identified C. sphaerospermum isolates 2, 6, 9, and 10 showed a genetic similarity reached 99%, 98%, 99%, and 99%, respectively, with those previously registered at the National Center for Biotechnology Information (NCBl). By comparing the nucleotide sequences of the identified C. sphaerospermum isolates with the sequences belong to the same fungi and available at NCBI, it was revealed that the identified C. sphaerospermum isolates 2, 6, 9, and 10 have a genetic variation with those previously recorded at the National Center for Biotechnology Information (NCBl); therefore, the identified sequences of C. sphaerospermum isolates have been registered in GenBank database (NCBI) under the accession numbers MN896004, MN896107, MN896963, and MN896971, respectively.