scholarly journals Characterization of a Phytoplasma Associated with Frogskin Disease in Cassava

Plant Disease ◽  
2009 ◽  
Vol 93 (11) ◽  
pp. 1139-1145 ◽  
Author(s):  
Elizabeth Alvarez ◽  
Juan F. Mejía ◽  
Germán A. Llano ◽  
John B. Loke ◽  
Alberto Calari ◽  
...  
Keyword(s):  
Ribosomal Protein ◽  
Manihot Esculenta ◽  
Fragment Length Polymorphism ◽  
Rrna Gene ◽  
South American ◽  
Sequence Analyses ◽  
Chain Reaction ◽  
Nested Polymerase Chain Reaction ◽  
Polymerase Chain

Cassava frogskin disease (CFSD) is an economically important root disease of cassava (Manihot esculenta) in Colombia and other South American countries, including Brazil, Venezuela, Peru, Costa Rica, and Panama. The roots of severely affected plants are thin, making them unsuitable for consumption. In Colombia, phytoplasma infections were confirmed in 35 of 39 genotypes exhibiting mild or severe CFSD symptoms either by direct or nested polymerase chain reaction (PCR) assays employing ribosomal (r)RNA operon primer pairs. The CFSD-associated phytoplasmas were identified as group 16SrIII strains by restriction fragment length polymorphism (RFLP) and sequence analyses of amplified rDNA products, and results were corroborated by PCRs employing group 16SrIII-specific rRNA gene or ribosomal protein (rp) gene primers. Collectively, RFLP analyses indicated that CFSD strains differed from all phytoplasmas described previously in group 16SrIII and, on this basis, the strains were tentatively assigned to new ribosomal and ribosomal protein subgroups 16SrIII-L and rpIII-H, respectively. This is the first molecular identification of a phytoplasma associated with CFSD in cassava in Colombia.

scholarly journals Characterization of phytoplasmas related to 'Candidatus Phytoplasma asteris' subgroup rpI-L in Iran

2014 ◽  
Vol 54 (2) ◽  
pp. 199-203 ◽  
Author(s):  
Fereshteh Vali-Sichani ◽  
Masoud Bahar ◽  
Leila Zirak
Keyword(s):  
Fragment Length Polymorphism ◽  
Specific Primer ◽  
Sequence Analyses ◽  
Chain Reaction ◽  
Universal Primer ◽  
Disease Symptoms ◽  
Polymerase Chain ◽  
Pcr Assays ◽  
Niger Seed

Abstract In two of Iran's central provinces, several herbaceous plants showing phytoplasma disease symptoms were collected to detect 'Canididatus Phytoplasma asteris'-related phytoplasmas. Confirmation of an association of phytoplasmas with diseased plants was done using polymerase chain reaction (PCR) assays having the phytoplasma universal primer pairs P1/P7 followed by R16F2n/ R16R2 in nested PCR. Then, for detection of 'Ca. P. asteris', DNA samples were subjected to amplification of rp and tuf genes using specific primer pairs rp(I)F1A/rp(I)R1A and fTufAy/rTufAy, respectively. Restriction fragment length polymorphism or RFLP analyses of rp gene fragments using Tsp509I restriction enzyme as well as sequence analyses indicated that 'Ca. P. asteris'-related phytoplasmas associated with carrot, niger seed and scallion plants in these regions, belong to the rpI-L subgroup. This research is the first report of carrot, niger seed, and scallion infection with phytoplasmas belonging to the rpI-L subgroup.

scholarly journals Phytoplasma occurrence in apple trees in the Czech Republic

2011 ◽  
Vol 39 (No. 1) ◽  
pp. 7-12 ◽  
Author(s):  
R. Fialová ◽  
M. Navrátil ◽  
P. Válová
Keyword(s):  
Fragment Length Polymorphism ◽  
Rrna Gene ◽  
Polymorphism Analysis ◽  
Apple Proliferation ◽  
Chain Reaction ◽  
Apple Trees ◽  
The Czech Republic ◽  
High Incidence ◽  
Phytoplasma Infection ◽  
Polymerase Chain

The presence of phytoplasmas in apple trees with proliferation symptoms, rubbery wood symptoms and no symp­toms was determined by using polymerase chain reaction assays with primers amplifying phytoplasma 16S rRNA gene. Phytoplasmas were detected in all trees with proliferation symptoms. Positive tests for phytoplasma in the group of trees with rubbery wood symptoms and of those without symptoms revealed a relatively high incidence of latent phytoplasma infection. Using restriction fragment length polymorphism analysis, phytoplasma of the same identity – apple proliferation phytoplasma (subgroup 16SrX-A) – was recorded in all positively tested trees.  

scholarly journals Genotyping of Cryptosporidium species in children suffering from diarrhea in Sharkyia Governorate, Egypt

2021 ◽  
Vol 15 (10) ◽  
pp. 1539-1546
Author(s):  
Samira Metwally Mohammad ◽  
Magda Saad Ali ◽  
Sara Ahmed Abdel-Rahman ◽  
Raghda Abdelrahman Moustafa ◽  
Mohamed Hassan Sarhan
Keyword(s):  
Polymerase Chain Reaction ◽  
Restriction Fragment Length Polymorphism ◽  
Length Polymorphism ◽  
Fragment Length ◽  
Fragment Length Polymorphism ◽  
Cryptosporidium Species ◽  
Chain Reaction ◽  
Nested Polymerase Chain Reaction ◽  
Polymerase Chain ◽  
Restriction Fragment Length

Introduction: The protozoan parasite Cryptosporidium is one of the principal reasons for childhood diarrhea around the world. This work aimed to differentiate Cryptosporidium species among children suffering from diarrhea in Sharkyia Governorate, Egypt. Methodology: A total of 97 fecal specimens were taken from children suffering from diarrhea, attending Pediatric Clinics of Zagazig University and Al-Ahrar Hospitals. Full history was taken. Stool samples were examined microscopically using modified Ziehl–Neelsen stain for detection of Cryptosporidium oocysts. To identify Cryptosporidium genotypes, positive samples were then subjected to nested Polymerase chain reaction-restriction fragment length polymorphism targeting Cryptosporidium oocyst wall protein gene. Results: The overall detection rate was 27.8% (27/97) using modified Ziehl–Neelsen stain staining method. Using nested polymerase chain reaction, the gene was amplified in 85.2% (23/27). Restriction fragment length polymorphism analysis revealed that 65.2% (15/23) were Cryptosporidium hominis, 30.4% (7/23) were Cryptosporidium parvum, and one sample was not typed (4.4%). The significant risk factors associated with Cryptosporidium infection in children were animal contact and residence in rural areas. Conclusions: Cryptosporidium is a common enteric parasite affecting children in Sharkyia Governorate, Egypt, with the predominance of C. hominis genotype in children.

scholarly journals Molecular identification of Candidatus Phytoplasma spp. associated with Sophora yellow stunt in Iran

2017 ◽  
Vol 57 (2) ◽  
pp. 167-172 ◽  
Author(s):  
Touhid Allahverdi ◽  
Heshmatollah Rahimian ◽  
Mina Rastgou
Keyword(s):  
Phylogenetic Trees ◽  
Fragment Length Polymorphism ◽  
Chain Reaction ◽  
Mazandaran Province ◽  
Nested Polymerase Chain Reaction ◽  
Sophora Alopecuroides ◽  
Leaf Yellowing ◽  
Tehran Province ◽  
Polymerase Chain ◽  
West Azerbaijan

Abstract In the spring of 2012, sophora (Sophora alopecuroides L.) plants showing symptoms of leaf yellowing, little leaves and stunting were observed in Firooz-kuh (Tehran province), Sari (Mazandaran province) and Urmia (West Azerbaijan province) in Iran. Symptomatic plants from the three locations were subjected to nested polymerase chain reaction (PCR) to amplify 16SrRNA using primer pair P1/P7 followed by primer pair R16F2n/R16R2. The amplicons were purified, sequenced and the nucleotide sequences were analyzed by virtual restriction fragment length polymorphism (RFLP). The phytoplasmas associated with the yellows disease were identified as members of the 16SrIX group (Candidatus Phytoplasma phoenicium) and the 16SrXII group (Candidatus Phytoplasma solani). The two phytoplasmas were placed in 16SrIX-C and 16SrXII-A subgroups, respectively, in constructed phylogenetic trees. This is the first report on sophora yellows associated with Candidatus Phytoplasma phoenicium.

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