scholarly journals A multiplex polymerase chain reaction based method for rapid identification of two species of the genus Scolytus Geoffroy (Col: Curculionidae: Scolytinae) in Iran

2016 ◽  
Vol 48 (1) ◽  
pp. 11 ◽  
Author(s):  
S. Amini ◽  
R. Hosseini

Molecular identification is going to be more widespread in taxonomic studies of insects when traditional tools are problematic and time consuming. Identification of bark beetles, as one of the most important pests of forests, based on morphological characteristics is difficult because of their small size and morphological similarities. In the current study, species-specific primers were desi gned to identify two most abundant and morphologically similar bark beetle species <em>Scolytus ensifer</em> Eichhoff 1881 and <em>S. ecksteini</em> Butovitsch 1929, both found on <em>Ulmus minor</em> Miller in north of Iran. These species-specific primers successfully produced a fragment size with 318 bp and 465 bp of mitochondrial cytochrome oxidase 1 (<em>CO1</em>) gene in <em>S. ensifer </em>and<em> S. ecksteini</em> respectively. The results revealed tha t the multiplex polymerase chain reaction using the species-specific primers could amplify a unique band to distinguish these two species so confirmed this method as a convenient and quick tool to identify those two bark beetle species.

Plant Disease ◽  
1997 ◽  
Vol 81 (10) ◽  
pp. 1155-1160 ◽  
Author(s):  
K. Kageyama ◽  
A. Ohyama ◽  
M. Hyakumachi

This study was conducted to sequence the rDNA internal transcribed spacer (ITS) region of Pythium ultimum and Pythium group HS, design species-specific primers for polymerase chain reaction (PCR), and detect P. ultimum from diseased seedlings using PCR. The sequence of the ITS region of P. ultimum was identical with that of Pythium group HS. The results support the reports that the HS group is an asexual strain of P. ultimum. Using PCR, the primer pair K1+K3, designed on portions of the sequence of the ITS region, amplified isolates of P. ultimum and the HS group but not isolates of 20 other Pythium species. DNA extracts from damped-off seedlings were not amplified, but a 10-fold dilution of the extracts with Tris-EDTA (TE) buffer diluted the inhibitors and allowed PCR amplification. The primer pair used detected P. ultimum from a single diseased seedling.


2007 ◽  
Vol 97 (10) ◽  
pp. 1290-1297 ◽  
Author(s):  
Jennifer S. Falacy ◽  
Gary G. Grove ◽  
Walter F. Mahaffee ◽  
Heather Galloway ◽  
Dean A. Glawe ◽  
...  

A polymerase chain reaction (PCR) assay employing species-specific primers was developed to differentiate Erysiphe necator from other powdery mildews common in the northwest United States. DNA was extracted from mycelia, conidia, and/or chasmothecia that were collected from grape leaves with a Burkard cyclonic surface sampler. To differentiate E. necator from other erysiphaeceous fungi, primer pairs Uncin144 and Uncin511 were developed to select unique sequences of the internal transcribed spacer regions of E. necator. Using these primers in PCR amplifications, a 367-bp amplicon specific to E. necator was generated, but no amplicons were generated from other erysiphaceous species collected from 48 disparate hosts representing 26 vascular plant families. The PCR limit of detection was one to five conidia of E. necator placed directly into reaction mixtures or 100 to 250 conidia placed on glass rods coated with silicon grease. During field studies, this PCR assay facilitated the detection of E. necator inoculum in air samples within hours of sample rod collection and prior to disease onset. Amplification of E. necator DNA did not occur when the PCR assay was conducted on vineyard air samples collected while grapes were dormant or during periods when vine growth occurred but E. necator remained dormant. The initial PCR detection of E. necator of the season occurred during seasonal ascospore releases caused by precipitation events between bud burst and the prebloom period during the 3 years of the study. Detection ceased for 7 to 11 days following ascospore release and then resumed several days prior to the observance of microscopic symptoms and signs of powdery mildew in the field. Results of this study represent the initial step toward the goal of incorporating an inoculum availability component into current and future grapevine powdery mildew risk assessment models.


2006 ◽  
Vol 96 (6) ◽  
pp. 637-647 ◽  
Author(s):  
K. L. Schroeder ◽  
P. A. Okubara ◽  
J. T. Tambong ◽  
C. A. Lévesque ◽  
T. C. Paulitz

Traditional methods of quantifying Pythium spp. rely on the use of selective media and dilution plating. However, high variability is inherent in this type of enumeration and counts may not be representative of the pathogenic population of Pythium spp. Variable regions of the internal transcribed spacer of the rDNA were used to design species-specific primers for detection and quantification of nine Pythium spp. from soils in eastern Washington. Primer pairs were designed for Pythium abappressorium, P. attrantheridium, P. heterothallicum, P. irregulare group I, P. irregulare group IV, P. paroecandrum, P. rostratifingens, P. sylvaticum, and P. ultimum and used with real-time polymerase chain reaction. Standard curves were generated for each of the species using SYBR Green I fluorescent dye for detection of amplification. Seventy-seven isolates of Pythium were screened to confirm specificity of each primer set. DNA was extracted from soil and standard curves were generated for P. irregulare group I, P. irregulare group IV, and P. ultimum to correlate populations of each species in the soil with quantities of DNA amplified from the same soil. Examination of raw field soils revealed results similar to those observed in previous studies. This new technique for the quantification of Pythium spp. is rapid and accurate, and will be a useful tool in the future study of these pathogenic Pythium spp.


2002 ◽  
Vol 14 (4) ◽  
pp. 347-353 ◽  
Author(s):  
José Miguel Arriaga ◽  
Noah D. Cohen ◽  
James N. Derr ◽  
M. Keith Chaffin ◽  
Ronald J. Martens

Species-specific primers for the polymerase chain reaction (PCR) for the detection of Rhodococcus equi were developed. These primers were based on unique DNA fragments produced from R. equi reference strains and field isolates. Following random amplification of polymorphic DNA from R. equi and R. rhodochrous with a set of 40 arbitrary 10–base pair (bp) primers, a pair of species-specific primers was designed to detect a unique 700-bp fragment of R. equi chromosomal DNA. This PCR product was limited to R. equi and was not detectable in other Rhodococcus species or in a panel of additional gram-positive and gram-negative bacteria.


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