Browsing by Author "Sayed, Yasmin"

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    Universal and Specific 16S-23Sr RNA PCR Primers for Identification of Phytoplasma associated with sesame in Egypt.
    (International Journal of Advanced Research in Biological Sciences, 2007) A.Youssef, Sahar; Sayed, Yasmin; S. Hassan, Osama; Safwat, Gehan; A. Shalaby, A.
    Sesame (Sesamum indicum L.), family Pedaliaceae is one of the most ancient cultivated oilseed crops among the edible annual group in Egypt and all over the world. Phytoplasmas are pathogens of many plant species throughout the world including sesame causing a large variety of symptoms ranged from mild yellowing to death of infected plants. Symptomatic samples including green leaf-like floral organs, virescence, phyllody and proliferation were collected from infected sesame field in Giza Governorate. This research was undertaken to develop a diagnostic tool to identify phytoplasmas recently discovered infecting sesame in Egypt, and to classify them according to their phylogenetic group. Direct and nested PCR primers of 16S-23SrRNA gene, paired with phytoplasma universal primer followed by strain-specific PCR primers were used in this study. Spacer Region (SR) primers were employed for identification of Phytoplasma group associated with sesame symptoms. Results showed the presences of mixed infections of phytoplasma in the tested sesame samples which collected from the field with different type of Phytoplasma like symptoms. Results also indicated that polymerase chain reaction with primers from sequencing of 16S-32S rRNA and from SR opened new paths for research on phytoplasma identification and classification. Nested PCR has been applied to overcome problems related to sensitivity of phytoplasma detection, although this approach is more time consuming and subject to template. Unfortunately, nested-PCR also meets some difficulties: unspecific bands, false positives or negatives caused by DNA and contamination of single or nested PCR. Therefore, confirmation of PCR results by using different primer pair combinations (generic and group-specific) seems to be the way for correct phytoplasma identification in the examined sesame
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    Universal and Specific 16S-23Sr RNA PCR Primers forIdentification of Phytoplasma associated with sesame in Egypt
    (International Journal of Advanced Research in Biological Sciences, 2017) A Youssef, Sahar; Sayed, Yasmin; S Hassan, Osama; Safwat, Gehan; Shalaby, AA
    Sesame (Sesamum indicumL.), familyPedaliaceaeis one of the most ancient cultivated oilseed cropsamong the edible annualgroup in Egypt and all over the world. Phytoplasmas are pathogens of many plant species throughout the world including sesamecausing a large variety of symptoms ranged from mild yellowing to death of infected plants.Symptomaticsamples includinggreen leaf-like floral organs,virescence, phyllody and proliferationwere collected from infected sesame field in GizaGovernorate.This research was undertaken to develop a diagnostic tool to identify phytoplasmas recently discovered infectingsesame in Egypt, and to classify them according to their phylogenetic group. Direct and nested PCR primers of 16S-23SrRNAgene, paired with phytoplasma universal primer followed by strain-specific PCR primers were used in this study. Spacer Region(SR) primers were employed for identification of Phytoplasma group associated with sesame symptoms. Results showed thepresences of mixed infections of phytoplasma in the tested sesame samples which collected from the field with different typeofPhytoplasma like symptoms. Results also indicated thatpolymerase chain reaction with primers from sequencing of 16S-32SrRNA and from SR opened new paths for research on phytoplasma identification and classification. Nested PCR has been appliedto overcome problems related to sensitivity of phytoplasma detection, although this approach is more time consuming and subjectto template. Unfortunately, nested-PCR also meets some difficulties: unspecific bands, false positives or negatives caused byDNA and contaminationof single or nested PCR. Therefore, confirmation of PCR results by using different primer paircombinations (generic and group-specific) seems to be the way for correct phytoplasma identification in the examined sesamesamples