Characterization of Pyrenophora tritici-repentis in Tunisia and Comparison with a Global Pathogen Population

Plant Disease ◽  
2021 ◽  
Author(s):  
Marwa Laribi ◽  
Alireza Akhavan ◽  
Sarrah M'Barek ◽  
Amor Yahyaoui ◽  
Stephen Ernest Strelkov ◽  
...  

Pyrenophora tritici-repentis (Ptr) causes tan spot, an important foliar disease of wheat. A collection of Ptr isolates from Tunisia, located in one of the main secondary centers of diversification of durum wheat, was tested for phenotypic race classification based on virulence on a host differential set, and for the presence of the necrotrophic effector (NE) genes ToxA, ToxB , and toxb by PCR analysis. While races 2, 4, 5, 6, 7, and 8 were identified according to their virulence phenotypes, PCR testing indicated the presence of ‘atypical’ isolates that induced necrosis on the wheat differential ‘Glenlea’, but lacked the expected ToxA gene, suggesting the involvement of other NEs in the Ptr/wheat interaction. Genetic diversity and the Ptr population structure were explored further by examining 59 Tunisian isolates and 35 isolates from Algeria, Azerbaijan, Canada, Iran, and Syria using 24 simple sequence repeat markers. Average genetic diversity, overall gene flow and percentage polymorphic loci were estimated as 0.58, 2.09 and 87%, respectively. Analysis of molecular variance showed that 81% of the genetic variance occurred within populations and 19% between populations. Cluster analysis by the unweighted pair group method indicated that ToxB- isolates grouped together and were distantly related to ToxB+ isolates. Based on Nei’s analysis, the global collection clustered into two distinct groups according to their region of origin. The results suggest that both geographic origin and the host-specificity imposed by different NEs can lead to differentiation among Ptr populations.

Genome ◽  
2002 ◽  
Vol 45 (6) ◽  
pp. 1175-1180 ◽  
Author(s):  
F J Massawe ◽  
M Dickinson ◽  
J A Roberts ◽  
S N Azam-Ali

Bambara groundnut (Vigna subterranea (L.) Verdc), an African indigenous legume, is popular in most parts of Africa. The present study was undertaken to establish genetic relationships among 16 cultivated bambara groundnut landraces using fluorescence-based amplified fragment length polymorphism (AFLP) markers. Seven selective primer combinations generated 504 amplification products, ranging from 50 to 400 bp. Several landrace-specific products were identified that could be effectively used to produce landrace-specific markers for identification purposes. On average, each primer combination generated 72 amplified products that were detectable by an ABI Prism 310 DNA sequencer. The polymorphisms obtained ranged from 68.0 to 98.0%, with an average of 84.0%. The primer pairs M-ACA + P-GCC and M-ACA + P-GGA produced more polymorphic fragments than any other primer pairs and were better at differentiating landraces. The dendrogram generated by the UPGMA (unweighted pair-group method with arithmetic averaging) grouped 16 landraces into 3 clusters, mainly according to their place of collection or geographic origin. DipC1995 and Malawi5 were the most genetically related landraces. AFLP analysis provided sufficient polymorphism to determine the amount of genetic diversity and to establish genetic relationships in bambara groundnut landraces. The results will help in the formulation of marker-assisted breeding in bambara groundnut.Key words: under-utilized, African legume, molecular markers.


HortScience ◽  
2018 ◽  
Vol 53 (5) ◽  
pp. 613-619 ◽  
Author(s):  
Ghazal Baziar ◽  
Moslem Jafari ◽  
Mansoureh Sadat Sharifi Noori ◽  
Samira Samarfard

Ficus carica L. is one of the most ancient fruit trees cultivated in Persia (Iran). The conservation and characterization of fig genetic resources is essential for sustainable fig production and food security. Given these considerations, this study characterizes the genetic variability of 21 edible F. carica cultivars in the Fars Province using random amplified polymorphic DNA (RAPD) markers. The collected cultivars were also characterized for their morphological features. A total of 16 RAPD primers produced 229 reproducible bands, of which, 170 loci (74.43%) were polymorphic with an average polymorphic information content (PIC) value of 0.899. Genetic analysis using an unweighted pair-group method with arithmetic averaging (UPGMA) revealed genetic structure and relationships among the local germplasms. The dendrogram resulting from UPGMA hierarchical cluster analysis separated the fig cultivars into five groups. These results demonstrate that analysis of molecular variance allows for the partitioning of genetic variation between fig groups and illustrates greater variation within fig groups and subgroups. RAPD-based classification often corresponded with the morphological similarities and differences of the collected fig cultivars. This study suggests that RAPD markers are suitable for analysis of diversity and cultivars’ fingerprinting. Accordingly, understanding of the genetic diversity and population structure of F. carica in Iran may provide insight into the conservation and management of this species.


2007 ◽  
Vol 132 (3) ◽  
pp. 357-367 ◽  
Author(s):  
P. Escribano ◽  
M.A. Viruel ◽  
J.I. Hormaza

Cherimoya (Annona cherimola Mill.) is an underused fruit crop with a clear niche for expansion in subtropical climates. In this study, 16 simple sequence repeat (SSR) loci were used to find molecular polymorphisms among 279 cherimoya accessions from a worldwide ex situ field germplasm collection. A total of 79 amplification fragments were amplified with 16 pairs of SSR primers, with an average of 4.9 bands/SSR. Mean expected and observed heterozygosities averaged 0.53 and 0.44, respectively. The total value for the probability of identity was 4.34 × 10−8. The SSRs studied resulted in 267 different fingerprinting profiles, of which 258 were unique genotypes; the rest were putative cases of synonymies or mislabeling errors. Unweighted pair group method with arithmetic averages (UPGMA) cluster analysis indicated the relationships among the analyzed accessions, showing some specific groups related to their geographical origins. Analysis of molecular variance (AMOVA) was performed to examine the distribution of genetic variation of the 148 accessions collected from putative cherimoya origin areas in Ecuador and Peru, showing that the major variations occurred within valleys in each country. The results confirmed the usefulness of microsatellites for identification of genetic diversity and geographic origin of cherimoya and are discussed in terms of their implications for ex situ conservation of cherimoya genetic resources.


1970 ◽  
Vol 38 (2) ◽  
pp. 153-161 ◽  
Author(s):  
Saaimatul Huq ◽  
Md Shahidul Islam ◽  
Abu Ashraqur Sajib ◽  
Nadim Ashraf ◽  
Samiul Haque ◽  
...  

Characterization of sixteen jute genotypes, from Corchorus olitorius L. and Corchorus capsularis L. using jute specific SSR marker attained a high polymorphism value of 92.20%. A total of 171 different alleles were amplified by 27 primer pairs with a mean of 6.33 ± 2.04 alleles per locus. The genetic diversity was also relatively high (0.81 ± 0.06). The Un-weighted Pair-group Method with Arithmetic averages (UPGMA) cluster analysis of the 16 jute genotypes produced a dendogram, which was in concordance with known information. The study reinforces the utility of SSR primers for providing useful and high levels of markers for individual plant genotypes even with a narrow genetic base. Key words: Jute; Genetic diversity; SSR; Genotypes; Polymorphism DOI: 10.3329/bjb.v38i2.5140 Bangladesh J. Bot. 38(2): 153-161, 2009 (December)  


2021 ◽  
Vol 7 (9) ◽  
pp. 713
Author(s):  
Abdelhameed Elameen ◽  
Svein Stueland ◽  
Ralf Kristensen ◽  
Rosa F. Fristad ◽  
Trude Vrålstad ◽  
...  

Saprolegnia parasitica is recognized as one of the most important oomycetes pests of salmon and trout species. The amplified fragment length polymorphism (AFLP) and method sequence data of the internal transcribed spacer (ITS) were used to study the genetic diversity and relationships of Saprolegnia spp. collected from Canada, Chile, Japan, Norway and Scotland. AFLP analysis of 37 Saprolegnia spp. isolates using six primer combinations gave a total of 163 clear polymorphic bands. Bayesian cluster analysis using genetic similarity divided the isolates into three main groups, suggesting that there are genetic relationships among the isolates. The unweighted pair group method with arithmetic mean (UPGMA) and principal coordinate analysis (PCO) confirmed the pattern of the cluster analyses. ITS analyses of 48 Saprolegnia sequences resulted in five well-defined clades. Analysis of molecular variance (AMOVA) revealed greater variation within countries (91.01%) than among countries (8.99%). We were able to distinguish the Saprolegnia isolates according to their species, ability to produce oogonia with and without long spines on the cysts and their ability to or not to cause mortality in salmonids. AFLP markers and ITS sequencing data obtained in the study, were found to be an efficient tool to characterize the genetic diversity and relationships of Saprolegnia spp. The comparison of AFLP analysis and ITS sequence data using the Mantel test showed a very high and significant correlation (r2 = 0.8317).


2014 ◽  
Vol 23 (2) ◽  
pp. 189-199 ◽  
Author(s):  
Shefali Boonerjee ◽  
M. Nurul Islam ◽  
M. I. Hoque ◽  
R. H. Sarker

Using 20 decamer random primers molecular characterization of 18 tea (Camellia sinensis L.) clones of Bangladesh was made. All the primers showed significant amplification in PCR analysis. A total of 755 bands was produced in all the 18 tea clones with an average of 37.75 RAPD bands per primer. Among all the bands 97.41% were polymorphic in nature. The molecular size of the amplified DNA fragments ranged from 250 to 5000 bp. Ten unique bands were amplified from the genome of the 18 tea clones. The values of pairwise genetic distance ranged from 24.0 to 59.0 indicating the presence of a wide range of genetic diversity. The highest genetic distance 59 was found between the clone BT16 and BT2, whereas the lowest (24.0) between BT18 and BT5. The dendrogram based on Nei’s genetic distance was constructed using un-weighted Pair Group of Arithmetic Mean (UPGMA) segregating the 18 tea clones into two major clusters: BT9 and BT13 in cluster 1 and the remainder of 16 clones in cluster 2. Cluster 2 is further sub-divided into many sub-clusters. Cluster analysis revealed that while the genotype BT5 is closely related to BT18,  BT1 and BT2 showed similarity with BT8. Genotypes BT1 and BT13 were widely diverse genetically. D. O. I. http://dx.doi.org/10.3329/ptcb.v23i2.175010 Plant Tissue Cult. & Biotech. 23(2): 189-199, 2013  (December)


2001 ◽  
Vol 126 (1) ◽  
pp. 7-12 ◽  
Author(s):  
F. Sanz-Cortés ◽  
M.L. Badenes ◽  
S. Paz ◽  
A. Íñiguez ◽  
G. Llácer

Forty olive (Olea europaea L.) cultivars from Valencia, Spain, were screened using random amplified-polymorphic DNA (RAPD) markers. Eighteen selected decamer primers produced 34 reproducible amplification fragments that were then used as polymorphic markers. The resulting combinations of these RAPD markers were used to discriminate 40 cultivars. Results were analyzed for similarity among cultivars and the relatedness of polymorphisms obtained between cultivars agreed with previous results using isozymes. Unweighted pair group method cluster analysis of their similarity values revealed two main groups divided according to geographic origin within Valencia. A third group, which included two Spanish cultivars from regions outside of Valencia, was clustered separately from the Valencian cultivars. RAPD technology proved useful in discriminating closely related cultivars. There was no apparent clustering of cultivars by fruit size or other morphological traits.


2011 ◽  
Vol 9 (2) ◽  
pp. 210-213 ◽  
Author(s):  
Luís Rocha ◽  
Sandra Martins ◽  
Valdemar Carnide ◽  
Fernando Braga ◽  
Carlos Carvalho

Woad (Isatis tinctoria L.) was introduced in Europe in ancient times to produce indigo, a natural blue pigment used mainly for dyestuff. This species was cultivated in Portugal until the beginning of the 20th century, especially in the inner North and South. A set of nine inter-simple sequence repeat (ISSR) markers generated 177 reproducible fragments, of which 171 were polymorphic. The mean number of fragments/accession was 111, ranging between 100 (Portugal-Coimbra) and 124 (Poland). The total polymorphism observed was 0.3272, the average polymorphism was 0.1784 and the gene differentiation between accessions was 0.4546. Polymorphism ranged between 53.8% (Austria) and 73.1% (Belgium). The genetic relationship among woad accessions was obtained with unweighted pair group method with arithmetic mean dendrogram based on a molecular marker, clearly clustering the woad accessions according to their geographic origin. The genetic diversity observed in this collection shows that there is a considerable potential for its improvement and that ISSR could be used to evaluate intra- and inter-accession similarities in I. tinctoria species.


2021 ◽  
Vol 13 (12) ◽  
pp. 6830
Author(s):  
Murat Guney ◽  
Salih Kafkas ◽  
Hakan Keles ◽  
Mozhgan Zarifikhosroshahi ◽  
Muhammet Ali Gundesli ◽  
...  

The food needs for increasing population, climatic changes, urbanization and industrialization, along with the destruction of forests, are the main challenges of modern life. Therefore, it is very important to evaluate plant genetic resources in order to cope with these problems. Therefore, in this study, a set of ninety-one walnut (Juglans regia L.) accessions from Central Anatolia region, composed of seventy-four accessions and eight commercial cultivars from Turkey, and nine international reference cultivars, was analyzed using 45 SSR (Simple Sequence Repeats) markers to reveal the genetic diversity. SSR analysis identified 390 alleles for 91 accessions. The number of alleles per locus ranged from 3 to 19 alleles with a mean value of 9 alleles per locus. Genetic dissimilarity coefficients ranged from 0.03 to 0.68. The highest number of alleles was obtained from CUJRA212 locus (Na = 19). The values of polymorphism information content (PIC) ranged from 0.42 (JRHR222528) to 0.86 (CUJRA212) with a mean PIC value of 0.68. Genetic distances were estimated according to the UPGMA (Unweighted Pair Group Method with Arithmetic Average), Principal Coordinates (PCoA), and the Structure-based clustering. The UPGMA and Structure clustering of the accessions depicted five major clusters supporting the PCoA results. The dendrogram revealed the similarities and dissimilarities among the accessions by identifying five major clusters. Based on this study, SSR analyses indicate that Yozgat province has an important genetic diversity pool and rich genetic variance of walnuts.


2011 ◽  
Vol 46 (9) ◽  
pp. 1035-1044 ◽  
Author(s):  
Patrícia Coelho de Souza Leão ◽  
Sérgio Yoshimitsu Motoike

The objective of this work was to analyze the genetic diversity of 47 table grape accessions, from the grapevine germplasm bank of Embrapa Semiárido, using 20 RAPD and seven microsatellite markers. Genetic distances between pairs of accessions were obtained based on Jaccard's similarity index for RAPD data and on the arithmetic complement of the weighted index for microsatellite data. The groups were formed according to the Tocher's cluster analysis and to the unweighted pair‑group method with arithmetic mean (UPGMA). The microsatellite markers were more efficient than the RAPD ones in the identification of genetic relationships. Information on the genetic distance, based on molecular characteristics and coupled with the cultivar agronomic performance, allowed for the recommendation of parents for crossings, in order to obtain superior hybrids in segregating populations for the table grape breeding program of Embrapa Semiárido.


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