scholarly journals Magnaporthe oryzae Genetic Diversity and Its Outcomes on the Search for Durable Resistance

10.5772/33479 ◽  
2012 ◽  
Author(s):  
Klaus Konrad ◽  
Juliana Vieira ◽  
Rubens Marschalek ◽  
Alexander de ◽  
Ester Wickert
Keyword(s):  
Genetic Diversity ◽  
Magnaporthe Oryzae ◽  
Durable Resistance

Genetic diversity and pathogenicity dynamics of Magnaporthe oryzae in the Wuling Mountain area of China

2018 ◽  
Vol 153 (3) ◽  
pp. 731-742 ◽  
Author(s):  
Xin Xu ◽  
Wu Yang ◽  
Ke Tian ◽  
Jie Zheng ◽  
Xinqiong Liu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Magnaporthe Oryzae ◽  
Mountain Area

Assessment of genetic diversity in Italian rice germplasm related to agronomic traits and blast resistance (Magnaporthe oryzae)

2010 ◽  
Vol 27 (2) ◽  
pp. 233-246 ◽  
Author(s):  
Odile Faivre-Rampant ◽  
Gianluca Bruschi ◽  
Pamela Abbruscato ◽  
Stefano Cavigiolo ◽  
Anna Maria Picco ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Magnaporthe Oryzae ◽  
Agronomic Traits ◽  
Blast Resistance ◽  
Rice Germplasm

scholarly journals Genotyping-by-Sequencing-Based Genetic Analysis of African Rice Cultivars and Association Mapping of Blast Resistance Genes Against Magnaporthe oryzae Populations in Africa

2017 ◽  
Vol 107 (9) ◽  
pp. 1039-1046 ◽  
Author(s):  
Emmanuel M. Mgonja ◽  
Chan Ho Park ◽  
Houxiang Kang ◽  
Elias G. Balimponya ◽  
Stephen Opiyo ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Association Mapping ◽  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Blast Resistance ◽  
Genotyping By Sequencing ◽  
Rice Breeding ◽  
Rice Cultivars ◽  
R Genes ◽  
African Rice

Understanding the genetic diversity of rice germplasm is important for the sustainable use of genetic materials in rice breeding and production. Africa is rich in rice genetic resources that can be utilized to boost rice productivity on the continent. A major constraint to rice production in Africa is rice blast, caused by the hemibiotrophic fungal pathogen Magnaporthe oryzae. In this report, we present the results of a genotyping-by-sequencing (GBS)-based diversity analysis of 190 African rice cultivars and an association mapping of blast resistance (R) genes and quantitative trait loci (QTLs). The 190 African cultivars were clustered into three groups based on the 184K single nucleotide polymorphisms generated by GBS. We inoculated the rice cultivars with six African M. oryzae isolates. Association mapping identified 25 genomic regions associated with blast resistance (RABRs) in the rice genome. Moreover, PCR analysis indicated that RABR_23 is associated with the Pi-ta gene on chromosome 12. Our study demonstrates that the combination of GBS-based genetic diversity population analysis and association mapping is effective in identifying rice blast R genes/QTLs that contribute to resistance against African populations of M. oryzae. The identified markers linked to the RABRs and 14 highly resistant cultivars in this study will be useful for rice breeding in Africa.

Genetic analysis of durable resistance to Magnaporthe oryzae in the rice accession Gigante Vercelli identified two blast resistance loci

2015 ◽  
Vol 291 (1) ◽  
pp. 17-32 ◽  
Author(s):  
Simona Urso ◽  
Francesca Desiderio ◽  
Chiara Biselli ◽  
Paolo Bagnaresi ◽  
Laura Crispino ◽  
...  
Keyword(s):  
Genetic Analysis ◽  
Magnaporthe Oryzae ◽  
Blast Resistance ◽  
Durable Resistance ◽  
Rice Accession

scholarly journals Genetic Diversity in Diploid and Tetraploid Late Blight Resistant Potato Germplasm

HortScience ◽  
2002 ◽  
Vol 37 (1) ◽  
pp. 178-183 ◽  
Author(s):  
Dilson A. Bisognin ◽  
David S. Douches
Keyword(s):  
Genetic Diversity ◽  
Late Blight ◽  
Durable Resistance ◽  
Late Blight Resistance ◽  
Blight Resistance ◽  
Pair Group ◽  
Potato Germplasm ◽  
Genetic Base ◽  
The Matrix ◽  
Isozyme Loci

An understanding of the genetic relationship within potato germplasm is important to establish a broad genetic base for breeding purposes. The objective of this study was to assess the genetic diversity of potato (Solanum tuberosum subsp. tuberosum Hawkes) germplasm that can be used in the development of cultivars with resistance to late blight caused by Phytophthora infestans (Mont.) de Bary. Thirty-three diploid and 27 tetraploid late blight resistant potato clones were evaluated for their genetic diversity based on 11 isozyme loci and nine microsatellites. A total of 35 allozymes and 42 polymorphic microsatellite fragments was scored for presence or absence. The germplasm was clustered based on the matrix of genetic similarities and the unweighted pair group means analysis of the isozyme and microsatellite data, which were used to construct a dendrogram using NTSYS-pc version 1.7. Twenty-three allozymes and DNA fragments were unique to the wild species. The diploid Solanum species S. berthaultii Hawkes and S. microdontum Bitter formed two distinct phenetic groups. Within S. microdontum, three subgroups were observed. The tetraploid germplasm formed another group, with S. sucrense Hawkes in one subgroup and the cultivated potato and Russian hybrids in another subgroup. Based upon the genetic diversity and the level of late blight resistance, S. microdontum and S. sucrense offer the best choice for strong late blight resistance from genetically diverse sources. This potato germplasm with reported late blight resistance should be introgressed into the potato gene pool to broaden the genetic base to achieve stronger and more durable resistance.

scholarly journals Evaluation of Genetic Diversity in Iranian Rice (Oryza Sativa L.) Cultivars for Resistance Blast Disease (Magnaporthe Oryzae) Using Microsatellite (SSR) Markers.

2019 ◽  
Author(s):  
Farzaneh Farahzadi ◽  
Asa Ebrahimi ◽  
Vahid Zarrinnia ◽  
Reza Azizinezhad
Keyword(s):  
Genetic Diversity ◽  
Ssr Markers ◽  
Magnaporthe Oryzae ◽  
Oryza Sativa L ◽  
Indica Rice ◽  
Molecular Data ◽  
Blast Disease ◽  
Analysis Group ◽  
The People ◽  
The World

AbstractRice plays an important role in feeding the world’s population, specially the people who live in developing countries. Rice occupies one third of the world’s crops and provides 35 to 60 percent of calories consumed by 2.7 billion people in the world. More than 90 percent of world’s rice is produced and consumed in Asia. Blast disease caused by Magnaporthe Oryzae is one of the most important diseases of rice in the world. This study was evaluated the Power of ten blast specific SSR Markers in determination genetic diversity between thirty cultivars of Indica rice. The phenotypic evaluation was also performed using Magnaporthe Oryzae in stage of three or four leaves. The total of 23 effective alleles with an average of 2.21 alleles per locus affecting microsatellite markers were amplified in genotypes. The total of 28 alleles was also observed per locus with 2.8 average. Also, the average of PIC was estimated 42.0 for markers. The RM204 marker has the maximum of PIC (0.60) and RM413 marker has the minimum of PIC (0.081). The calculated similarities result between molecular data by Jacard similarity coefficient and UPGMA algorithm have divided thirty studied genotypes into three categories. This analysis between coordinates decides the cluster analysis group. In phenotypic testing, the calculated similarities between phenotypic has also occurred using coefficient similarity Dist and UPGMA algorithm. According to phenotypic evaluation the population was also divided into three groups. According to T-Student test for comparing the phenotypic and genotypic data, SSR markers "RM277" and “RM8225” were linked to semi-susceptible, and resistant phenotype.

scholarly journals The Effects of Founding Events and Agricultural Practices on the Genetic Structure of Three Metapopulations of Globodera pallida

2001 ◽  
Vol 91 (8) ◽  
pp. 753-758 ◽  
Author(s):  
Rolf T. Folkertsma ◽  
Paul van Koert ◽  
Jeroen N. A. M. Rouppe van der Voort ◽  
Koen E. de Groot ◽  
Jan E. Kammenga ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
The Netherlands ◽  
Sandy Loam ◽  
Durable Resistance ◽  
Agricultural Practices ◽  
Globodera Pallida ◽  
Allele Frequencies ◽  
Genetic Constitution ◽  
Two Dimensional Gel Electrophoresis ◽  
Local Populations

To assess the genetic constitution of the Globodera pallida populations in the Netherlands and the effects of agricultural practices, three geographically separated metapopulations, in total consisting of 226 local populations, were analyzed by two-dimensional gel electrophoresis (2-DGE) of total proteins. This technique allows the accurate assessment of allele frequencies in homogenates of mixtures of individuals. Based on the estimated average heterozygosity, the average proportion of polymorphic loci and the average number of alleles per locus, the genetic diversity among 226 local G. pallida populations was small. The small genetic basis of G. pallida in the Netherlands will facilitate the identification of Solanum genotypes with a broad and durable resistance to G. pallida. Instead of clusters of local populations with unique alleles, a continuous range of allele frequencies was observed. Analysis of the three metapopulations by the Shannon-Weaver index and Nei's GST revealed that the metapopulation from a region with sandy-loam soils was clearly distinguishable from the remaining two; the local populations within this metapopulation were more similar and the genetic diversity within the individual local populations was significantly higher than the local populations from the two remaining regions. These regions are characterized by wider crop rotation schemes and a very limited use of nematicides. The less intensive cultivation of potatoes in these regions with sandy-clay soils resulted in relatively little variation within and more variation between local nematode populations. To our knowledge, the effects of agricultural practices on the genetic constitution of potato cyst nematode populations have not been pinpointed before.

scholarly journals Genetic Diversity and Mating Type Distribution of Pseudocercospora fijiensis on Banana in Uganda and Tanzania

2020 ◽  
Author(s):  
Janet Njeri Kimunye ◽  
Norman Muzhinji ◽  
Diane Mostert ◽  
Altus Viljoen ◽  
Aletta E. van der Merwe ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
East Africa ◽  
Mating Type ◽  
Spatial Scales ◽  
Durable Resistance ◽  
Population Variation ◽  
Black Sigatoka ◽  
Single Spore ◽  
Type Distribution ◽  
Pseudocercospora Fijiensis

Black Sigatoka, caused by Pseudocercospora fijiensis, is a major foliar disease of banana and plantain worldwide. Little information on the genetic diversity and population structure of the pathogen is available for East Africa, which is needed to design effective and durable disease management strategies. We genotyped 319 single-spore isolates of P. fijiensis collected from seven regions in Uganda and Tanzania and five from Nigeria using 16 simple sequence repeat markers and mating type specific primers. Isolates from each country and region within country were treated as populations and subpopulations, respectively. A total of 296 multi-locus genotypes (MLGs) were recovered, representing a clonal fraction of 7%. Sub-populations had a moderate level of genetic diversity (Hexp = 0.12-0.31; mean 0.29). Mating type distribution did not deviate from equilibrium (MAT1-1: MAT1-2, 1:1 ratio) in Uganda, but in Tanzania the mating types were not in equilibrium (4:1 ratio). Index of association tests (IA and r̄d) showed that all populations were at linkage equilibrium (P>0.05), supporting the hypothesis of random association of alleles. These findings are consistent with a pathogen that reproduces both clonally and sexually. Low and insignificant levels of population differentiation were detected, with 90% of the variation occurring among isolates within subpopulations. The high intra-population variation has implications in breeding for resistance to P. fijiensis, as isolates differing in aggressiveness and virulence are likely to exist over small spatial scales. Diverse isolates will be required for resistance screening to ensure selection of banana cultivars with durable resistance to Sigatoka in East Africa

scholarly journals Genetic diversity of barley accessions from Ethiopia for the powdery mildew resistance

2019 ◽  
pp. 7-10
Author(s):  
R. A. Abdullaev ◽  
T. V. Lebedeva ◽  
N. V. Alpatieva ◽  
O. V. Yakovleva ◽  
O. N. Kovaleva ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Molecular Markers ◽  
Powdery Mildew ◽  
Laboratory Experiments ◽  
Powdery Mildew Resistance ◽  
Durable Resistance ◽  
Phenotypic Screening ◽  
Allelic Variants ◽  
North West ◽  
Resistance Expression

Nine hundred and twenty five Ethiopian barley accessions were studied under laboratory experiments for juvenile resistance to North West population of powdery mildew casual agent Blumeria graminis (DC.) Golovin ex Speer f. sp. hordei Marchal. Based on phenotypic screening, the 27 accessions resistant to the pathogen were selected and 47 forms were heterogeneous for the studied character. The resistant and susceptible plants of the examined accessions were analyzed with the use of molecular markers developed for identification of the mlo11 allele. Fifteen accessions carrying the mlo11 allele which determines durable resistance of most modern barley varieties to powdery mildew were revealed. The accessions differed by the resistance expression that can be explained both by the manifestation of other resistance genes which are inadequate to the mlo11 and also by the presence of different mlo11 allelic variants in the genotypes of the selected accessions. The resistance to B. graminis of other 59 forms is controlled by the effective genes which are different from mlo11.

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