scholarly journals Population Structure ofMycosphaerella graminicolaand Location of Genes for Resistance to the Pathogen: Recent Advances in Argentina

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
María Rosa Simón ◽  
Cristina A. Cordo ◽  
Nadia S. Castillo ◽  
Paul C. Struik ◽  
Andreas Börner
Keyword(s):  
Population Structure ◽  
Genetic Variability ◽  
Geographic Area ◽  
Mycosphaerella Graminicola ◽  
Septoria Tritici ◽  
Wheat Cultivars ◽  
Leaf Blotch ◽  
The World ◽  
New Germplasm ◽  
New Cultivars

Leaf blotch of wheat (Septoria triticiRob. ex Desm., teleomorphMycosphaerella graminicola(Fückel) Schröt. in Cohn) causes significant losses in wheat. During the last decades studies about the genetic variability of the pathogen and location of the resistance have been intensive around the world. The knowledge about the genetic variation ofM. graminicolais very important because it could allow us to determine which genotypes predominate within a geographic area. It also can be used to evaluate the germplasm resistance of wheat cultivars with isolates with high genetic differences. In addition, the knowledge of the genes conditioning resistance in different genotypes allows getting precise combination in new germplasm. The incorporation of the known genes in new cultivars could contribute to broadening the resistance to the pathogen. A paper about genetic variability of the pathogen and location of the resistance, with special emphasis in the work carried out in Argentina, is presented.

scholarly journals Avirulence in the Wheat Septoria tritici Leaf Blotch Fungus Mycosphaerella graminicola Is Controlled by a Single Locus

2000 ◽  
Vol 13 (12) ◽  
pp. 1375-1379 ◽  
Author(s):  
Gert H. J. Kema ◽  
Els C. P. Verstappen ◽  
Cees Waalwijk
Keyword(s):  
Fragment Length Polymorphism ◽  
Random Amplified Polymorphic Dna ◽  
Mycosphaerella Graminicola ◽  
Septoria Tritici ◽  
Wheat Cultivars ◽  
Leaf Blotch ◽  
Dna Analyses ◽  
Differential Cultivars ◽  
Complex Locus ◽  
F2 Progeny

Segregation of avirulence in Mycosphaerella graminicola, a heterothallic ascomycete that causes wheat septoria tritici leaf blotch, was studied in F1, BC1, and F2 populations by inoculation assays on five wheat cultivars in the seedling stage and by amplified fragment length polymorphism and random amplified polymorphic DNA analyses. F1 was generated by crossing isolates IPO323 (avirulent) and IPO94269 (virulent). All F1, BC1, and F2 progeny isolates were virulent on the susceptible check cultivar Taichung 29 and were avirulent on the resistant check cultivar Kavkav-K4500. Avirulence segregation was observed in F1 and in several BC1 and F2 generations on the differential cultivars Shafir, Kavkaz, and Veranopolis at a 1:1 ratio. Avirulence for the three differential cultivars always cosegregated. We conclude that avirulence in isolate IPO323 is controlled by a single, seemingly complex locus.

Microsatellite markers provide evidence for sexual reproduction of Mycosphaerella graminicola in Saskatchewan

Genome ◽  
2004 ◽  
Vol 47 (5) ◽  
pp. 789-794 ◽  
Author(s):  
M Razavi ◽  
G R Hughes
Keyword(s):  
Genetic Diversity ◽  
Genetic Variability ◽  
Sexual Reproduction ◽  
Primary Source ◽  
Mycosphaerella Graminicola ◽  
Septoria Tritici Blotch ◽  
Septoria Tritici ◽  
Allelic Series ◽  
Evolutionary Potential ◽  
Wheat Field

This study examined the genetic structure of a Saskatchewan population of Mycosphaerella graminicola, cause of the foliar disease Septoria tritici blotch of wheat. Such knowledge is valuable for understanding the evolutionary potential of this pathogen and for developing control strategies based on host resistance. Nine pairs of single-locus microsatellite primers were used to analyze the genomic DNA of 90 isolates of M. graminicola that were collected using a hierarchical sampling procedure from different locations, leaves, and lesions within a wheat field near Saskatoon. Allelic series at eight different loci were detected. The number of alleles per locus ranged from one to five with an average of three alleles per locus. Genetic diversity values ranged from 0.04 to 0.67. Partitioning the total genetic variability into within- and among-location components revealed that 88% of the genetic variability occurred within locations, i.e., within areas of 1 m2, but relatively little variability occurred among locations. Low variability among locations and a high degree of variability within locations would result if the primary source of inoculum was airborne ascospores, which would be dispersed uniformly within the field. This finding was confirmed by gametic disequilibrium analysis and suggests that the sexual reproduction of M. graminicola occurs in Saskatchewan.Key words: Mycosphaerella graminicola, SSR markers, sexual reproduction, genetic diversity.

scholarly journals Reaction of winter wheat genotypes to infection by Mycosphaerella graminicola(Fuckel) Schroeter

2013 ◽  
Vol 55 (1) ◽  
pp. 233-246
Author(s):  
Ewa Mirzwa-Mróz ◽  
Czesław Zamorski
Keyword(s):  
Winter Wheat ◽  
Broad Spectrum ◽  
Mycosphaerella Graminicola ◽  
Wheat Breeding ◽  
Septoria Tritici ◽  
Wheat Cultivars ◽  
Breeding Lines ◽  
Wheat Genotypes ◽  
Winter Wheat Cultivars

The response of Polish winter wheat genotypes to <i>M.graminicola</i> (preliminary experiments and cultivar collections) was observed in different regions of Poland. Observations were carried out in 1995-1999. The winter wheat genotypes showed a broad spectrum of reaction to this pathogen. Between 1997 and 1999 the highest degree of infection on winter wheat breeding lines was noted in Kończewice. During this time no genotypes free from infection were observed (preliminary breeding experiments). Cultivars with no symptoms of <i>Septoria tritici</i> blotch (Leszczyńska Wczesna and Żelazna) were found among old genotypes in Słupia Wielka only in earlier experiments (1995-1996). In the years 1997-1999 the winter wheat cultivars were classified into groups on the basis of their response to the pathogen. The degree of infection for the majority cultivars was quite high.

Analysis of expressed sequence tags from the wheat leaf blotch pathogen Mycosphaerella graminicola (anamorph Septoria tritici)

2005 ◽  
Vol 42 (5) ◽  
pp. 376-389 ◽  
Author(s):  
John Keon ◽  
John Antoniw ◽  
Jason Rudd ◽  
Wendy Skinner ◽  
John Hargreaves ◽  
...  
Keyword(s):  
Expressed Sequence Tags ◽  
Mycosphaerella Graminicola ◽  
Septoria Tritici ◽  
Leaf Blotch ◽  
Wheat Leaf ◽  
Expressed Sequence

scholarly journals Reactions of winter wheat to Mycosphaerella graminicola (anamorph Septoria tritici)

2012 ◽  
Vol 58 (1) ◽  
pp. 97-100
Author(s):  
Lubomir Věchet ◽  
Eliška Sychrová
Keyword(s):  
Winter Wheat ◽  
Mycosphaerella Graminicola ◽  
Septoria Tritici ◽  
Wheat Cultivars ◽  
High Occurrence ◽  
Winter Wheat Cultivars ◽  
Clear Plastic ◽  
Leaf Segments ◽  
Seedling Leaf

Reaction of six winter wheat cultivars and lines (Vlasta, Šárka, Charger, 00ST022, SG-U8044C a SG-U2113B) to <i>Mycosphaerella graminicola</i> isolate BR-331 and UH-05 on leaf segments of the detached second seedling leaf of cultivars placed on water agar with bezimidazole in clear plastic box were tested. The isolate BR-331 produced high occurrence of the disease in the cultivar Šárka, middle occurrence (the percentage covered by lesions bearing pycnidia) in the cultivar Vlasta and SG-U8044C and low occurrence in the line 00ST0022. The isolate UH-105 produced high occurrence in the cultivar 00ST022 and middle occurrence in the cultivar Vlasta. The cultivar Charger was resistant. The cultivar Šárka was attacked at least. Results show on different virulence of <i>M. graminicola</i> isolates to wheat cultivars.

Surveys of speckled leaf blotch and other foliar diseases of wheat in Victoria, 1974 to 1978

1980 ◽  
Vol 20 (102) ◽  
pp. 94 ◽  
Author(s):  
JS Brown ◽  
RG Paddick
Keyword(s):  
Yield Loss ◽  
Mycosphaerella Graminicola ◽  
Septoria Tritici ◽  
Puccinia Recondita ◽  
Puccinia Graminis ◽  
Yield Losses ◽  
Leaf Blotch ◽  
Average Percentage ◽  
Leptosphaeria Nodorum ◽  
Glume Blotch

The severity of speckled leaf blotch (Mycosphaerella graminicola (Fuckel) Schroeter, Septoria tritici Rob. ex Desm.) in wheat crops was surveyed in the Wimmera during the 1974-77 seasons and in all the major wheat growing areas of Victoria in 1978. Speckled leaf blotch was found in all crops and the severity varied greatly within and between seasons. The average percentage of affected area on the penultimate leaf of main tillers was 24%, 28%, 1.5%, 0% and 9.4%, respectively, for the successive seasons. The corresponding grain yield losses were estimated at 19, 21, 5, 0 and 12% by using an experimentally derived relation between yield loss and disease severity. In 1978, glume blotch (Leptosphaeria nodorum (Miiller, Septoria nodorum (Berk.) Berk.), stem rust (Puccinia graminis Pers. f sp. tritici Erikss and Henn.), leaf rust (Puccinia recondita Rob. ex Desm. f sp, tritici Erikss) and powdery mildew (Erysiphe graminis DC. f sp. tritici E. Marchal) occurred in 8%, 3%, 1% and 0.5%, respectively, of the crops sampled. These surveys have shown speckled leaf blotch to be the most important foliar disease of wheat in Victoria.

scholarly journals Occurrence of Septoria tritici blotch in 1994-1996

2013 ◽  
Vol 50 (1-2) ◽  
pp. 11-26
Author(s):  
Czesław Zamorski ◽  
Bogdan Nowicki ◽  
Ewa Mirzwa-Mróz
Keyword(s):  
Winter Wheat ◽  
Weather Condition ◽  
Mycosphaerella Graminicola ◽  
Septoria Tritici Blotch ◽  
Septoria Tritici ◽  
Wheat Cultivars ◽  
Breeding Lines ◽  
High Infection ◽  
Winter Wheat Cultivars ◽  
Very High

The aim of the work was to study an occurrence and intensity of septoria tritici blotch on wheat in different regions of Poland as well as reaction of winter wheat cultivars and breeding lines to infection by <em>Mycosphaerella graminicola</em> (Fuckel) Schroeter (an. <em>Septoria tritici</em> ( Rob. ex Desm .) under field conditions. Observation conducted during 1994-1996 indicated on occurrence of septoria tritici blotch each year and on important infection degree of winter wheat by <em>Mycosphaerella gruminicola</em> in some regions of the country. The highest infection was noted in 1995 and the lowest in 1994. Infection degree for majority of cultivars was quite high. Some cultivars and lines were characterized by very high infection. Among them were the old (Kujawianka Więcławska and Wysokolitewka Sztywnosłoma) and the newest (Tercja) cultivars. On some old cultivars (Leszczyńska Wczesna and Żelazna) even no traces of infection were observed although favourable weather condition existance and the presence of neighbourhood diseased plants. Field observation of cultivars and breeding lines showed different reaction of tested wheat genotypes to <em>Mycosphaerella graminicola</em> infection.

scholarly journals Assessment of Genetic Diversity of Tea Germplasm for Its Management and Sustainable Use in Korea Genebank

Forests ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 780 ◽  
Author(s):  
Kyung Jun Lee ◽  
Jung-Ro Lee ◽  
Raveendar Sebastin ◽  
Myoung-Jae Shin ◽  
Seong-Hoon Kim ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Simple Sequence Repeat ◽  
Sustainable Use ◽  
Tea Plant ◽  
South American ◽  
Analysis Of Molecular Variance ◽  
The World ◽  
Simple Sequence ◽  
New Cultivars

Tea (Camellia sinensis (L.) O. Kuntze) is cultivated in many developing Asian, African, and South American countries, and is the most widely consumed beverage in the world. It is of critical importance to understand the genetic diversity and population structure of tea germplasm for effective collection, conservation, and utilization. In this study, 410 tea accessions collected from South Korea were analyzed using 21 simple sequence repeat (SSR) markers. Among 410 tea accessions, 85.4% (350 accessions) were collected from Jeollanam-do. A total of 286 alleles were observed, and the genetic diversity and evenness were estimated to be on average 0.79 and 0.61, respectively, across all the tested samples. Using discriminant analysis of principal components, four clusters were detected in 410 tea accessions. Among them, cluster 1 showed a higher frequency of rare alleles (less than 1%). Using the calculation of the index of association and rbaD value, each cluster showed a clonal mode of reproduction. The result of analysis of molecular variance (AMOVA) showed that most of the variation observed was within populations (99%) rather than among populations (1%). The present study revealed the presence of lower diversity and simpler population structure in Korean tea germplasms. Consequently, more attention should be focused on collecting and conserving the new tea individuals to broaden genetic variation of new cultivars in future breeding of the tea plant.

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