ملخص البحث :

Abstract: The study was carried out with the aim of isolating and diagnosing 10 fungi isolated from infected potato tubers collected from some local markets in Karbala governorate. These fungal isolates were diagnosed using the Polymerase chain reaction (PCR) technique and the determination of the nucleotide sequence of the PCR-amplified products using ITS1 and ITS4 primer pair. The results of the analysis of the sequence of nucleotide sequences of the PCR products using the BLAST (Basic Local Alignment Search Tool) program showed that all the diagnosed fungal isolates belong to F. solani. When comparing the sequences of nucleotide sequences of the identified isolates, it was observed that there were genetic similarities among some of the isolates as well as between them and other isolates belonging to the same fungus previously registered in the National Center for Biotechnology Information, NCBI database, including those isolated from Iraq (MN124374), Egypt (MT793786), India (MW045600), and China (MWO41204) at 100% similarity

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: Tomato is an important vegetable crop due to increased production and consumption all over the world. Numerous viruses attack tomato plants but Tomato yellow leaf curl virus (TYLCV) is one of the serious concerns under the open and protected cultivations. In the present study, we collected leaf samples from TYLCV infected plants grown in some farms located in the desert regions of Najaf and Karbala provinces in Iraq. We diagnosed 16 disease-inducing viral isolates using the polymerase chain reaction and the degenerate coat protein (CP) primer pair was used to determine the nucleotide sequence of the amplified PCR product. BLAST results revealed that all identified isolates belong to TYLCV. Among the identified TYLCV isolates, it was evident that the highest differences in the CP nucleotide sequences were found in the TYLCV isolates 7 and 13 ranging between 97%-99%. Whiteflies-mediated inoculation of tomato plants (Super Marmande and Moneymaker) with the isolates 7 and 13 separately induced different symptoms in severity and the time of symptoms appearance. Biological control agents i.e. Trichoderma asperellum, Trichoderma longibrachiatum, and Trichoderma asperlloides were mixed with soil. Plants grown in soil infested with the fungi T. asperlloides and T. asperellum did not show typical symptoms of TYLCV infection and the absence of the virus was confirmed by PCR. Whereas, all plants grown in soil infested with the fungus T. longibrachiatum exhibited TYLCV infection but with fewer symptoms compared with the more severe symptoms noticed in the control treatment. Moreover, application of the nanoparticles notably silver nitrate (AgNO3), magnesium oxide (MgO), and iron oxide (Fe2O3) in 1200, 1400, 1600, 1800, 2000, and 2200 ppm concentrations did not prevent infection of TYLCV, but it was noted that there was a significant reduction in the displayed symptoms and silver nitrate (AgNO3) nanoparticles were the most effective in preventing the symptoms compared with the other nanoparticles

ملخص البحث :

Abstract: The study included isolation and purification of the two fungi Alternaria solani and Fusarium oxysporum fromtomato plants that showed symptoms of early blight and fusarium wilt. The pathogenicity of the two fungi A.solani and F.oxysporum, as the percentage of germination of cabbage seeds was 32.4% and 21.6% compared with 98.6% for the controltreatment and there was no significant effect on the germination with the fungus T. harizianum. The results also showed that10% concentration of cold, hot and alcoholic Aloe vera extract significantly inhibited the radial growth of F. oxysporum andA. solani, where it was 0.83 and 0.26 cm with cold extract, while with hot extract the radial growth of F. oxysporum and A. solaniis 1.38 and 1.22 cm, respectively each and with alcoholic extract the radial growth of pathogenic fungi F.oxysporum and A.solani was 0.20 and 0.7 cm, respectively each compared with 3.25 and 2.4 cm in treatment. In comparison, this concentrationwas more inhibiting in the cold extract of Aloe vera. In the experiment that was conducted to see the effect of 10% concentration.From the cold extract of Aloe vera on the spores of the tested fungi, the results showed that this extract had a significantinhibitory ability on the germination of the spores of F. oxysporum and A. solani, where the number of spores developing was16.43 and 8.37, respectively, compared with 29.12 and 20.63, respectively, for each of them in the treatment. The results alsoshowed that the cold and hot Aloe vera extract had no significant inhibition on the growth of the fungus T.harizianum nor onthe germination of its spores, in contrast to the alcoholic extract Aloe vera only significantly inhibited the growth of thefungus as its radius was 2.2 cm compared with 3.11 cm in the control treatment

ملخص البحث :

Abstract: This study was carried out to isolate 19 isolates of the fungus Sclerotinia sclerotiorum from infected eggplants (Solanum melongena) grown in plastic houses located in some desert farms in Karbala and Najaf governorates, Iraq. These Sclerotinia sclerotiorum isolates were molecularly identified by the polymerase chain reaction technique (PCR) and determination of the nucleotide sequences of PCR products obtained from those isolates by amplifying with the primer pair ITS1 and ITS4. Results of the nucleotide sequence analysis, generated from the PCR-amplified products, using Basic Local Alignment Search Tool (BLAST) program revealed that all of the diagnosed fungal isolates belong to the fungus S. sclerotiorum. It was also observed by the comparison of the nucleotide sequences of the isolates that there is a 100% genetic similarity among most of the S. sclerotiorum isolates diagnosed in the current study, as well as with the other isolates formerly registered at NCBI (National Center for Biotechnology Information). The results also demonstrated that there were three isolates of S. sclerotiorum (3, 7 and 14) among the other isolates identified in this study were not previously recorded at NCBI. Therefore, they were recorded under the GenBank accession numbers: OM614596, OM614595 and OM614599, respectively.