scholarly journals Diversity of Biscogniauxia mediterranea within Single Stromata on Cork Oak

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Joana Henriques ◽  
Filomena Nóbrega ◽  
Edmundo Sousa ◽  
Arlindo Lima

Charcoal canker, caused by the fungus Biscogniauxia mediterranea, is one of the most frequent diseases of cork oak in Portugal. The pathogen has been considered a secondary invader that attacks only stressed hosts; however, in recent years, an increasing number of young trees exhibiting the disease symptoms have been recorded. A collection of monoascosporic cultures isolated from single stromata of B. mediterranea in cork oak from different locations was analyzed by means of microsatellite—Primed Polymerase Chain Reaction—using three microsatellite primers, in order to detect the genetic variation of the population thus discussing its plasticity and ability to adapt to different conditions. The results showed a high level of genetic variability among isolates obtained from the same stroma, being impossible to distinguish isolates from individual stromata neither from different geographical location.

Author(s):  
J. Albertyn ◽  
K.M. Tajbhai ◽  
R.R. Bragg

Psittacine beak and feather disease (PBFD) is a common disease of the psittacine species and is caused by the psittacine beak and feather disease virus (PBFDV). In this study the occurrence of the disease in ring-neck parakeets and budgerigars in South Africa suffering from feathering problems, using polymerase chain reaction as a diagnostic test was investigated. The genetic variation between viral isolates was also studied. Results indicate that PBFDV can be attributed to being the cause of feathering problems in some of the ring-neck parakeets and budgerigars in South Africa. Genetic variation of isolates occurs between species and individuals. A cheap and easy to use method of blood sample collection on filter paper for diagnostic purposes was also evaluated. It proved to be less stressful to the birds and did not inhibit further processes.


2006 ◽  
Vol 39 ◽  
pp. 77-88 ◽  
Author(s):  
S.C. Mehta ◽  
B.P. Mishra ◽  
M.S. Sahani

SummaryThe camel population in India is facing a severe decline which demands that immediate steps are taken to ensure its conservation. Characterisation is an integral part of the conservation program. The Polymerase Chain Reaction-Randomly Amplified Polymorphic DNA profile of unrelated camels of the Bikaneri (29), Jaisalmeri (30) and Kachchhi (18) breeds were analyzed. Reproducible polymorphic bands with varying frequencies among the three breeds of camel were obtained with five oligonucleotide primers. A total of 75 bands were amplified, of which 27 (36%) were polymorphic. The probability of obtaining identical fingerprints was observed to be the lowest in primer GC-10 (5.7%) followed by OP-08 (8.7%), GT-10 (11.3%), G-2 (15.5%) and G-1 (80%). Breed informative bands were amplified. The maximum genetic variability was observed in the Bikaneri (0.80±0.05) followed by the Kachchhi (0.84±0.06) and the Jaisalmeri (0.87±0.05) breeds. The inter-breed genetic distance estimates indicated a closer relationship in the Bikaneri-Kachchhi camels, (0.075), followed by the Jaisalmeri-Kachchhi (0.106) and Bikaneri-Jaisalmeri (0.132) breeds. A similar genetic relationship was observed when the degree of population subdivision was measured between the Bikaneri-Kachchhi (0.529), Jaisalmeri-Kachchhi (0.558) and Bikaneri-Jaisalmeri (0.566) breeds.


2010 ◽  
Vol 100 (4) ◽  
pp. 337-344 ◽  
Author(s):  
M. Catal ◽  
G. C. Adams ◽  
D. W. Fulbright

A quantitative polymerase chain reaction assay was developed that could detect DNA of Rhabdocline pseudotsugae and R. oblonga among DNA of Douglas fir needles to a limit as low as three copies of target DNA. Differential infection rates of two varieties (seed sources) of Douglas fir interplanted in a field were studied in relation to staggered bud breaks. Infection of Douglas fir var. San Isabel corresponded to ascospore release times for Rhabdocline spp., whereas infection of var. Shuswap Lake did not occur throughout the spore release period during 2 years of study, despite abundant inoculum and adequate moisture during bud break. Rhabdocline spp. DNA was never detected in Shuswap Lake and disease symptoms were not observed in any year. We provide evidence that Shuswap Lake is resistant and probably immune to Rhabdocline spp. infection and Rhabdocline needlecast under Michigan conditions.


1990 ◽  
Vol 36 (12) ◽  
pp. 2087-2092 ◽  
Author(s):  
K Kontula ◽  
K Aalto-Setälä ◽  
T Kuusi ◽  
L Hämäläinen ◽  
A C Syvänen

Abstract Three common alleles determine six apolipoprotein E (apo E) phenotypes that are associated with variations in serum cholesterol in the population. This genetic variation results from single nucleotide alterations at two DNA loci encoding the amino acid residues 112 and 158 of apo E. We compared results of apo E phenotyping carried out by isoelectric focusing with those of apo E genotyping accomplished by direct DNA analysis. In the latter, the target DNA was amplified by the polymerase chain reaction (PCR) and subsequently analyzed by digestion with the restriction enzyme Hha I, followed by polyacrylamide gel electrophoresis of the cleavage products. With one exception, these two techniques yielded similar results from all 40 samples tested. In addition, a rare variant form of apo E (phenotype E1) was analyzed separately and incorrectly diagnosed as E2 by the Hha I digestion method; the anticipated mutation in the codon 127 was, however, confirmed by demonstration of a new Taq I restriction site in this variant gene. These data confirm that the common isoforms of apo E usually arise from genetic variation of the codons 112 and 158 and demonstrate the feasibility of the PCR technique in apo E genotyping.


1999 ◽  
Vol 10 (10) ◽  
pp. 646-651 ◽  
Author(s):  
T Beattie ◽  
A Moyes ◽  
C Patrizio ◽  
H Young

Tetracycline resistant Neisseria gonorrhoeae (TRNG) contain a 25.2 MDa TetM plasmid encoding a 68KDa cytoplasmic protein which confers high-level tetracycline resistance. The aim of this study was to subtype all TRNG isolated in Scotland between 1992 and 1998. Subtyping was performed by a polymerase chain reaction (PCR) assay which characterizes the TetM plasmid as either the Dutch variant (443 base pair product) or the American variant (777 base pair product). Of the 78 TRNG isolates, 35 were the American variant and 43 were the Dutch variant. TRNG were distributed amongst 30 serovar/auxotype classes, the most common being 1A6/NR (11.5%), 1A6/P (14.1%) and 1B4/NR (14.1%). The country where infection was acquired was known for 36 of the 46 TRNG strains isolated between 1996 and 1998. All infections acquired in Asia and South America were the Dutch variant whereas all infections acquired in Africa were the American variant. A penicillinase plasmid was present in 66% (23/35) of the American variant TRNG compared with 51% (22/43) of the Dutch variant: the 3.2 MDa penicillinase plasmid was found in 87% of the American variant TRNG whereas the 4.4 MDa penicillinase plasmid was found in 68% of the Dutch variant TRNG. We conclude that subtyping of TRNG by PCR is a useful tool in studying the epidemiology of gonococcal infection due to plasmid-mediated resistant isolates.


2015 ◽  
Vol 7 (1) ◽  
pp. 219-225 ◽  
Author(s):  
V. Sunitha ◽  
T.V. K. Singh ◽  
V. Ramesh Babu ◽  
J. Satyanarayana

Genetic diversity in acephate, spinosad and Cry2Ab resistant Plutella xylostella collected from three states of India was assessed by RAPD markers. The DNA extracted from larvae was subjected to polymerase chain reaction using 10 RAPD primers. The highest number alleles (7) were produced by primer ABA-13, followed by six alleles each by primers ABA-2, 7, 8, 11, 14; five alleles each were produced by ABA-4, 9, 10, 12. UPGMA analysis clustered the acephate, spinosad and Cry2Ab treated P.xylostella populations into two groups with overall similarity level of 33%, 27% and 34% respectively. Cluster A consisted 11 samples while Cluster B consisted only F1 of acephate and spinosad treated Karnataka population. In Cry2Ab treated population Cluster B comprised 11 samples and Cluster A had out grouped singly i.e. F0 generation from Karnataka. The genetic variability between the acephate, spinosad and Cry2Ab treated populations ranged from 33 to 69%, 27 to 56% and 34 to 69% respectively. Acephate and spinosad treated F1 population and Cry2Ab treated F0 population from Karnataka were out grouped from rest of the populations.


2008 ◽  
Vol 21 (1) ◽  
pp. 07-14
Author(s):  
F. Easmin ◽  
M. S. Rahman ◽  
M. S. Islam ◽  
M. A. Samad ◽  
M. S. Alam

Genetic variation is a principal concern for the plant breeders. Genetic variation and relationship among high yielding rice varieties viz. Binadhan 4, Binadhan 5, Binadhan 6, Binasail, BRRI dhan28 and BRRI dhan29 were analyzed using four decamer random primers. Polymerase Chain Reaction (PCR) amplified 22 RAPD markers, of which 18 (81.82%) were polymorphic. The proportion of polymorphic loci and the gene diversity values were 59.09% and 0.25 for the Binadhan 4; 59.09% and 0.21 for Binadhan 6; 54.55% and 0.23 for Binasail; 54.55% and 0.19 for BRRI dhan29; 50.00% and 0.19 for Binadhan 5 and 45.45% and 0.18 for BRRI dhan28, respectively. The coefficient of gene differentiation (Gst) across all loci was calculated as 0.35 reflecting the existence of high level of genetic variation among the six modern rice varieties. UPGMA dendrogram based on Nei’s genetic distance segregated the six high yielding rice varieties into two clusters: all four mutant varieties viz. Binadhan 4, Binadhan 5, Binadhan 6 and Binasail formed one cluster and two varieties of BRRI grown in boro season, BRRI dhan28 and BRRI dhan29 grouped together in another cluster. Among the mutants, two boro season varieties, developed from the same parent, Binadhan 5 and Binadhan 6 grouped together with genetic distance of 0.10. Therefore, RAPD offer a reliable method to evaluate genetic variation and relatedness among the high yielding rice varieties.DOI: http://dx.doi.org/10.3329/bjpbg.v21i1.17042


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