scholarly journals Genetic Diversity of Spiroplasma citri Strains from Different Regions, Hosts, and Isolation Dates

2008 ◽  
Vol 98 (9) ◽  
pp. 960-968 ◽  
Author(s):  
A. F. S. Mello ◽  
R. K. Yokomi ◽  
U. Melcher ◽  
J. C. Chen ◽  
A. C. Wayadande ◽  
...  

Spiroplasma citri, a phloem-limited pathogen, causes citrus stubborn disease (CSD). Losses due to CSD in California orchards have grown over the past decade. To investigate the possibility of introduction or emergence of a new strain, a study of genetic diversity among S. citri strains from various locations was conducted using random amplified polymorphism DNA-polymerase chain reaction (RAPD-PCR) of 35 strains cultured from 1980 to 1993, and of 35 strains cultured from 2005 to 2006. Analysis using 20 primer pairs revealed considerable diversity among strains. However, no unique genetic signatures were associated with recently collected strains compared with those collected 15 to 28 years ago, and no geographically associated pattern was distinguishable. S. citri strains from carrot and daikon radish contain some unique DNA fragments, suggesting some host plant influence. Multiple strains from single trees also showed genetic diversity. Sequencing of five RAPD bands that differed among strains showed that diversity-related gene sequences include virus fragments, and fragments potentially encoding a membrane lipoprotein, a DNA modification enzyme, and a mobilization element. No differences in colony morphology were observed among the strains. The lack of correlation between PCR patterns and isolation date or collection site is inconsistent with the hypothesis that recent infections are due to the introduction or emergence of novel pathogen strains.

2011 ◽  
Vol 56 (4) ◽  
Author(s):  
B. Surendra Nath ◽  
W. Hassan ◽  
S. Nageswara Rao ◽  
N. Vijaya Prakash ◽  
S. Gupta ◽  
...  

AbstractRandom amplification of polymorphic DNA polymerase chain reaction (RAPD-PCR) was carried out to assess the genetic diversity of five new microsporidian isolates viz., NIWB-11bp, NIWB-12n, NIWB-13md, NIWB-14b and NIWB-15mb identified from the silkworms. A type species, NIK-1s_mys was used as control for comparison. Differences in the spore shape, length and width were observed. Of the 30 decamer random primers tested, 22 primers gave repeatable RAPD profiles and yielded a total of 143 fragments, of which 78 were polymorphic (55%). The resulting data was used to derive genetic similarity values for constructing a dendrogram. The neighbour joining method based on Dice coefficients indicate a major cluster comprising NIK-1s_mys, NIWB-11bp and NIWB-12n, whereas NIWB-13md, NIWB-14b and NIWB-15mb appear to be different from each other as well from the major cluster mentioned above which includes the type species (NIK-1s_mys). Based on the reproducibility of RAPD profiles, we are able to identify these microsporidians as different isolates. The RAPD technique may be useful in detecting sources of infection of this economically important domestic insect.


2011 ◽  
Vol 6 (8) ◽  
pp. 35-40
Author(s):  
Sangita Shrestha ◽  
Jaishree Sijapati ◽  
Neesha Rana ◽  
Diwa Malla ◽  
Prabha Regmi ◽  
...  

Of the 30 species (including five varieties) of the genus Swertia in Nepal, nine have been reported to possess medicinal properties. Among these, S. chirayita is the most valuable species, with high demand in domestic and international markets. Nepal’s S. chirayita and related species are being recklessly exploited for commercial purposes. Two problems that have emerged with this lucrative market are (a) adulteration and fraudulent labeling of S. chirayita, and (b) depletion of S. chirayita and allied species from their natural habitats. To address the problem of adulteration and conservation, we studied molecular genetic diversity in S. chirayita populations and developed a molecular diagnostic tool for the purposes of authentication. We studied intra-specific genetic diversity in S. chirayita using Polymerase Chain Reaction (PCR)-based Random Amplified Polymorphic DNA (RAPD) technique. As a preliminary step, we identified optimal RAPD-PCR reaction and cycling conditions by varying PCR reaction parameters such as concentration of template DNA, MgCl2, dNTPs, primer, Taq DNA polymerase and RAPD-PCR programs. The optimized PCR reaction and cycling conditions were then used in subsequent RAPD profiling experiments for the study of genetic diversity within S. chirayita populations from various geographical locations. Genetic diversity characterization of S. chirayita populations at the molecular level would furnish information with significant applications in the conservation and sustainable utilization of S. chirayita and its allied species in Nepal. Key words: Polymerase Chain Reaction, Random Amplified Polymorphic DNA, DNA fingerprinting, genetic diversity DOI: http://dx.doi.org/10.3126/hjs.v6i8.2699 Himalayan Journal of Sciences Vol.6 Issue 8 2010 pp.35-40


2016 ◽  
Vol 8 (6) ◽  
pp. 8849 ◽  
Author(s):  
Marc Timothy C. Tan ◽  
Joycelyn C. Jumawan ◽  
Jonas P. Quilang

Clarias macrocephalus Günther, 1864 is a Near Threatened freshwater catfish found in the Philippines and other Southeast Asian countries.  Its numbers have dwindled over the past few years because of habitat loss and competition.  This study examined the genetic diversity of the remaining viable populations of C. macrocephalus in the Philippines.  Primers were designed to amplify via polymerase chain reaction (PCR) the complete mitochondrial DNA (mtDNA) control region (870-bp) in 120 specimens collected from three sites: (1) Buguey, Cagayan; (2) Camalaniugan, Cagayan; and (3) Agusan del Sur.  Of the 120 sequences generated, only three haplotypes and two polymorphic sites were found. Overall haplotype and nucleotide diversity (h=0.479, π=0.00058) were alarmingly low, consistent with populations of other freshwater fishes that have experienced a genetic bottleneck.  The overall FST value was 0.80050, indicative of large genetic differentiation between populations.  The very low genetic variation found in all three C. macrocephalus populations calls for conservation and management efforts for the protection of the remaining populations of this economically important species.


Beverages ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 27
Author(s):  
Dimitrios Kontogiannatos ◽  
Vicky Troianou ◽  
Maria Dimopoulou ◽  
Polydefkis Hatzopoulos ◽  
Yorgos Kotseridis

Nemea and Mantinia are famous wine regions in Greece known for two indigenous grape varieties, Agiorgitiko and Moschofilero, which produce high quality PDO wines. In the present study, indigenous Saccharomyces cerevisiae yeast strains were isolated and identified from spontaneous alcoholic fermentation of Agiorgitiko and Moschofilero musts in order to evaluate their oenological potential. Random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) recovered the presence of five distinct profiles from a total of 430 yeast isolates. The five obtained strains were evaluated at microvinifications trials and tested for basic oenological and biochemical parameters including sulphur dioxide and ethanol tolerance as well as H2S production in sterile grape must. The selected autochthonous yeast strains named, Soi2 (Agiorgitiko wine) and L2M (Moschofilero wine), were evaluated also in industrial (4000L) fermentations to assess their sensorial and oenological characteristics. The volatile compounds of the produced wines were determined by GC-FID. Our results demonstrated the feasibility of using Soi2 and L2M strains in industrial fermentations for Agiorgitiko and Moschofilero grape musts, respectively.


2017 ◽  
Vol 142 (4) ◽  
pp. 260-264
Author(s):  
Ping Li ◽  
Dong Liu ◽  
Min Guo ◽  
Yuemin Pan ◽  
Fangxin Chen ◽  
...  

Sexual reproduction in the plant parasite Phytophthora capsici Leonian requires the interaction of two distinct mating types, A1 and A2. Co-occurrence of these mating types can enhance the genetic diversity of P. capsici and alter its virulence or resistance characteristics. Using an intersimple sequence repeat (ISSR) screen of microsatellite diversity, we identified, cloned, and sequenced a novel 1121-base pair (bp) fragment specific to the A1 mating type of P. capsici. Primers Pcap-1 and Pcap-2 were designed from this DNA fragment to specifically detect the A1 mating type. Polymerase chain reaction (PCR) using these primers amplified an expected 997-bp fragment from known A1 mating types, but yielded a 508-bp fragment from known A2 mating types. This PCR-based assay could be adapted to accurately and rapidly detect the co-occurrence of A1 and A2 P. capsici mating types from field material.


2021 ◽  
Vol 66 (3) ◽  
pp. 170-179
Author(s):  
Sengsoulichan Dethvongsa ◽  
Vu Nguyen Anh ◽  
Van Tran Khanh

RAPD (Randomly Amplified Polymorphic DNA) is an indicator for high and stable polymorphism, widely used in the study of the diversity of cassava. In this paper, the results of using 20 polymorphic primers OPK combined with the establishment of the phylogenetic tree to analyze the genetic diversity of 26 cassava varieties with different responses to waterlogging conditions by using the RAPD-PCR technique were presented. The purpose of this experiment was to show the genetic relevance of the studied cassava varieties. The results showed that the flood tolerance of cassava was not related to the polymorphism and branching characteristics of the stem. This information may be use as a basis for selecting flood-tolerant cassava varieties for cassava production, as well as the basis for selecting genetically different parents for breeding.


1997 ◽  
Vol 43 (6) ◽  
pp. 503-508 ◽  
Author(s):  
Leena Chakravarty ◽  
Joseph D. Kittle Jr. ◽  
Olli H. Tuovinen

An insertion sequence, designated as IST3091, was located adjacent to the putative origin of replication region of plasmid pTFI91 of Thiobacillus ferrooxidans TFI-91. The DNA sequence of the transposase gene of IST3091 revealed similarity with that of IS30, IS1086, IS4351, and the integrase gene of SpV1-R8A2 B (a bacteriophage of Spiroplasma citri). The sequence of IST3091 is 1063 bp long with partially matched 30-bp terminal inverted repeats. Several restriction fragments of plasmid pTFI91 of T. ferrooxidans containing the IST3091 element were cloned into the vector pHSG398. The hybrid plasmids (pBTL) were transformed into Escherichia coli NK7379 containing a miniF plasmid, which was devoid of transposable elements. The transposition function of the IST3091 element was confirmed by mobilizing hybrid plasmids via conjugation from transformed E. coli NK7379 (donor) to E. coli M8820 (recipient). The presence of the transposed element in transconjugants was detected by polymerase chain reaction amplification.Key words: insertion element, Thiobacillus ferrooxidans, transformation, transposase.


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