Identification and characterization of Xanthomonas albilineans causing sugarcane leaf scald in China using multilocus sequence analysis

2018 ◽  
Vol 68 (2) ◽  
pp. 269-277 ◽  
Author(s):  
M. S. Ntambo ◽  
J.-Y. Meng ◽  
P. C. Rott ◽  
M. Royer ◽  
L.-H. Lin ◽  
...  
Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1062 ◽  
Author(s):  
Maela León ◽  
Mónica Berbegal ◽  
José M. Rodríguez-Reina ◽  
Georgina Elena ◽  
Paloma Abad-Campos ◽  
...  

Two hundred and twenty-five Diaporthe isolates were collected from 2005 to 2019 in almond orchards showing twig cankers and shoot blight symptoms in five different regions across Spain. Multilocus DNA sequence analysis with five loci (ITS, tub, tef-1α, cal and his), allowed the identification of four known Diaporthe species, namely: D. amygdali, D. eres, D. foeniculina and D. phaseolorum. Moreover, a novel phylogenetic species, D. mediterranea, was described. Diaporthe amygdali was the most prevalent species, due to the largest number of isolates (85.3%) obtained from all sampled regions. The second most frequent species was D. foeniculina (10.2%), followed by D. mediterranea (3.6%), D. eres and D. phaseolorum, each with only one isolate. Pathogenicity tests were performed using one-year-old almond twigs cv. Vayro and representative isolates of the different species. Except for D. foeniculina and D. phaseolorum, all Diaporthe species were able to cause lesions significantly different from those developed on the uninoculated controls. Diaporthe mediterranea caused the most severe symptoms. These results confirm D. amygdali as a key pathogen of almonds in Spain. Moreover, the new species, D. mediterranea, should also be considered as a potential important causal agent of twig cankers and shoot blight on this crop.


Author(s):  
M. Pradeep ◽  
M. R. Reddy ◽  
T. R. Kannaki

Background: Runting-stunting syndrome (RSS) in chickens is a worldwide problem, attributed with several etiological agents. The present study aimed to identify the association of enteric viruses with RSS in different chicken flocks. Methods: Intestinal samples from 14 flocks of chicken of different age and breed and with or without RSS were collected randomly from necropsy samples, isolated nucleic acids, and screened for major enteric viruses by Polymerised chain reaction (PCR), using species-specific primers. Result: Chicken Parvovirus (ChPV) was identified in 100% of the flocks with RSS, in two of which ChPV alone was detected. While in others it was associated with Avian nephritis virus, Avian Rotavirus, Chicken astrovirus, and Fowl adenovirus in 80%, 50%, 30% and 10% flocks, respectively. RSS was reproduced and isolated ChPV by chicken embryo inoculation using the samples from ChPV alone infected cases. Sequence analysis of ChPV revealed closer association with Ecuodor isolates than the Asian isolates. The results indicated the presence of ChPV in Indian chicken flocks and its close association with RSS.


2015 ◽  
Vol 15 (1) ◽  
Author(s):  
Roghaieh Ashrafi ◽  
Katja Pulkkinen ◽  
Lotta-Riina Sundberg ◽  
Nina Pekkala ◽  
Tarmo Ketola

Plant Disease ◽  
2016 ◽  
Vol 100 (11) ◽  
pp. 2275-2280 ◽  
Author(s):  
N. Valasevich ◽  
B. Schneider

In Samochvalovichi, Belarus, apple and pear tree root samples were examined for the presence of phytoplasmas using a universal 16S rDNA-based PCR assay. Out of 27 tested apple trees, 23 were found to be infected by ‘Candidatus Phytoplasma mali’ and 46 out of 58 pear trees were positive for the presence of ‘Ca. P. pyri.’ Species were identified by sequence analysis of the 16S rDNA amplicons. The molecular diversity of the phytoplasma isolates was examined by analysis of an hflB gene using single-strand conformation polymorphism (SSCP) and sequence analysis. Therefore hflB gene amplicons from ‘Ca. P. mali’ and ‘Ca. P. pyri’ accessions were cloned after amplification. Screening of 640 cloned hflB fragments by SSCP analysis revealed the presence of eight different profiles for ‘Ca. P. mali’ and 12 different profiles for ‘Ca. P. pyri.’ The variants were sequenced and compared in multiple alignments. The nucleic acid homology among the hflB gene fragments ranged between 95.4 and 100.0% and 81.3 to 100.0% for ‘Ca. P. mali’ and ‘Ca. P. pyri,’ respectively, indicating a high genetic variability within the species. This is the first report on the occurrence of ‘Ca. P. mali’ and ‘Ca. P. pyri’ in Belarusian apple and pear trees and their molecular diversity.


Sign in / Sign up

Export Citation Format

Share Document