Genetic diversity and mating‐type frequency of Exserohilum turcicum in Turkey

2021 ◽  
Author(s):  
Emine Burcu Turgay ◽  
Arzu Çelik Oğuz ◽  
Fatih Ölmez ◽  
Berna Tunali ◽  
Şener Kurt ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Mating Type ◽  
Exserohilum Turcicum ◽  
Type Frequency

scholarly journals A PCR-based Assay for Distinguishing between A1 and A2 Mating Types of Phytophthora capsici

2017 ◽  
Vol 142 (4) ◽  
pp. 260-264
Author(s):  
Ping Li ◽  
Dong Liu ◽  
Min Guo ◽  
Yuemin Pan ◽  
Fangxin Chen ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Mating Type ◽  
Phytophthora Capsici ◽  
Mating Types ◽  
Sequence Repeat ◽  
Chain Reaction ◽  
Plant Parasite ◽  
Dna Fragment ◽  
Polymerase Chain ◽  
Microsatellite Diversity

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.

scholarly journals Characterization of Natural Isolates of Bipolaris maydis Associated with Mating Types, Genetic Diversity, and Pathogenicity in Fujian Province, China

Plant Disease ◽  
2020 ◽  
Vol 104 (2) ◽  
pp. 323-329
Author(s):  
Yuli Dai ◽  
Lin Gan ◽  
Hongchun Ruan ◽  
Niuniu Shi ◽  
Yixin Du ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Mating Type ◽  
Dna Polymorphism ◽  
Sweet Corn ◽  
Issr Markers ◽  
Bipolaris Maydis ◽  
Fujian Province ◽  
Field Isolates ◽  
Rational Distribution

Due to the natural destructiveness and persistence of the southern corn leaf blight (SCLB) fungus Bipolaris maydis (Nisikado et Miyake) Shoem, the characterization of B. maydis field isolates is essential to guide the rational distribution of resistant materials in corn-growing regions. In the present study, 102 field isolates collected from seven locations covering the entire region of Fujian Province, China, were assessed for mating type distribution, genetic diversity, and pathogenicity toward local sweet corn cultivars. Mating type detection via polymerase chain reaction indicated that 36.3 and 63.7% of isolates were MAT1-1 and MAT1-2, respectively; more than 80% of these isolates were confirmed using cross assays with known mating type isolates. Thirteen intersimple sequence repeat (ISSR) markers within and among two mating type populations revealed a high level of DNA polymorphism for all combined isolates and between MAT1-1 and MAT1-2 populations. The MAT1-2 population was more diverse based on DNA polymorphism than the MAT1-1 population. The value of GST was 0.0070, ranging from 0.0399 to 0.3044 based on analysis of combined isolates and individual regional populations, respectively, suggesting the presence of genetic differentiation in the two mating type populations from different locations. Pathogenicity assays revealed that both MAT1-1 and MAT1-2 populations were pathogenic to all 11 local sweet corn cultivars tested in this study. The potential of sexual reproduction, existence of genetic diversity in the two mating type populations, and pathogenicity suggest that B. maydis populations have independently clonally adapted under natural field conditions during corn cultivation.

scholarly journals Virulence, Molecular Diversity, and Mating Type of Curvularia lunata in China

Plant Disease ◽  
2019 ◽  
Vol 103 (7) ◽  
pp. 1728-1737 ◽  
Author(s):  
Dan Zhang ◽  
Fen Wang ◽  
Jiamei Zhao ◽  
Jiaying Sun ◽  
Dandan Fu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Mating Type ◽  
Molecular Diversity ◽  
Fragment Length Polymorphism ◽  
Selective Pressure ◽  
Phenotypic Expression ◽  
Curvularia Lunata ◽  
Type I ◽  
Resistant Varieties ◽  
Differential Hosts

Curvularia leaf spot (CuLS), caused by Curvularia lunata, is a devasting foliar disease in the maize-growing regions of China. Resistant varieties were widely planted in these regions in response to CuLS. However, over time, C. lunata has gradually adapted to the selective pressure and, in recent years, the incidence of CuLS has increased. To assess the correlation between virulence and genetic diversity, a total of 111 isolates was collected from 15 maize-growing regions located in nine provinces in China. These isolates were evaluated for virulence on maize using nine differential hosts: Shen135, CN165, Mo17, Luyuan92, 78599, Ye478, B73, E28, and Huangzaosi. To evaluate the genetic diversity, 657 polymorphic amplified fragment length polymorphism markers were generated. Results showed that the isolates could be grouped into three pathotypes according to the phenotypic expression of the differential inbred lines. Isolates were clustered into two genetic diversity groups and further divided into subgroups. However, the correlation between virulence and genetic diversity grouping was low. Also, there was a low correlation observed between pathotype and geographic distribution. The ratio of mating type I to mating type II for all isolates was close to 3:4.

Genetic Diversity and Population Structure of Phyllosticta citriasiana in China

2020 ◽  
Author(s):  
Yibing Zeng ◽  
Tao Xiong ◽  
Bei Liu ◽  
Elma Carstens ◽  
Xiangling Chen ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Mating Type ◽  
Tan Spot ◽  
Long Distance ◽  
High Genetic Diversity ◽  
Geographic Population ◽  
Sexual And Asexual Reproduction ◽  
Geographic Populations ◽  
Genetic Clusters

Phyllosticta citriasiana is the causal agent of citrus tan spot, an important pomelo disease in Asia. At present, there is little or no information on the epidemiology or population structure of P. citriasiana. Using simple sequence repeat (SSR) markers, 94 isolates obtained from three pomelo production regions in southern/southeastern China were analyzed. The analyses showed high genetic diversity in each of the three geographic populations. A STRUCTURE analysis revealed two genetic clusters among the 94 isolates, one geographic population was dominated by genotypes in one cluster while the other two geographic populations were dominated by genotypes of the second cluster. P. citriasiana has a heterothallic mating system with two idiomorphs, MAT1-1 and MAT1-2. Analyses using mating type-specific primers revealed that both mating types were present in all three geographic populations, and in all three populations the mating type ratios were in equilibrium. Although the sexual stage of the fungus has not been discovered yet, analyses of allelic associations indicated evidence for sexual and asexual reproduction within and among populations. Despite the observed genetic differentiation among the three geographic populations, evidence for long-distance gene flow was found.

scholarly journals Genetic Diversity and Differentiation inPhoma betaePopulations on Table Beet in New York and Washington States

Plant Disease ◽  
2019 ◽  
Vol 103 (7) ◽  
pp. 1487-1497 ◽  
Author(s):  
Lori B. Koenick ◽  
Niloofar Vaghefi ◽  
Noel L. Knight ◽  
Lindsey J. du Toit ◽  
Sarah J. Pethybridge
Keyword(s):  
Genetic Diversity ◽  
New York ◽  
Mating Type ◽  
Gene Diversity ◽  
Management Strategies ◽  
Allelic Diversity ◽  
Genotypic Diversity ◽  
Reproduction Mode ◽  
Inoculum Source ◽  
Seed Crops

Phoma betae is an important seedborne pathogen of table beet worldwide that is capable of causing foliar, root, and damping-off diseases. Ten microsatellite and mating type markers were developed to investigate the genetics of P. betae populations in table beet root crops in New York and in table beet seed crops in Washington, from where table beet seed is predominantly sourced. The markers were used to characterize 175 isolates comprising five P. betae populations (two from New York and three from Washington), and they were highly polymorphic with an allelic range of 4 to 33 and an average of 11.7 alleles per locus. All populations had high genotypic diversity (Simpson’s complement index = 0.857 to 0.924) and moderate allelic diversity (Nei’s unbiased gene diversity = 0.582 to 0.653). Greater differentiation observed between populations from the two states compared with populations within the same state suggested that an external inoculum source, such as windblown ascospores, may be homogenizing the populations. However, most genetic diversity (87%) was among individual isolates within populations (pairwise index of population differentiation = 0.127; P = 0.001), suggesting that local within-field inoculum source(s), such as infested field debris or infected weeds, may also be important in initiating disease outbreaks. Standardized index of association, proportion of compatible pairs of loci, and mating type ratio calculations showed evidence for a mixed reproduction mode in all populations. These findings could be useful in designing more effective management strategies for diseases caused by P. betae in table beet production.

scholarly journals Fertility and Mating Type Frequency in Indian Isolates of Sclerospora graminicola, the Downy Mildew Pathogen of Pearl Millet

Plant Disease ◽  
2006 ◽  
Vol 90 (2) ◽  
pp. 211-214 ◽  
Author(s):  
B. Pushpavathi ◽  
R. P. Thakur ◽  
K. Chandrashekara Rao
Keyword(s):  
Genetic Structure ◽  
Downy Mildew ◽  
Pearl Millet ◽  
Mating Type ◽  
Production Potential ◽  
Sclerospora Graminicola ◽  
Indian Isolates ◽  
Type Test ◽  
Type Frequency ◽  
Sexual Mating

Sclerospora graminicola, the downy mildew pathogen of pearl millet, is an oomycetous obligate parasite which reproduces by both sexual and asexual means. Fertility and mating type frequencies were studied in 70 single-zoospore isolates (SZIs) obtained from seven representative oo-sporic isolates (Sg 021, Sg 048, Sg 110, Sg 139, Sg 149, Sg 152, and Sg 153) of S. graminicola collected from major pearl millet-growing states of India. Of the 70 SZIs tested for fertility according to oospore production potential, 62 were self-sterile and 8 were self-fertile, indicating the low occurrence of homothallism in the S. graminicola populations. The sexual mating type test of the 70 SZIs, conducted by pairing each isolate with the two standard mating type tester isolates PT2 (Mat A) and PT 3 (Mat B), revealed 28 (40.0%) isolates of Mat A, 33 (47.14%) of Mat B, 8 (11.43%) of both Mat A and Mat B, and 1 (1.43%) as unknown. The frequencies of Mat A and Mat B were in approximately equal proportions among the isolates tested, except in three parental isolates. Implications of these results in understanding the dynamic genetic structure of S. graminicola population and potential for evolution of new virulence in the pathogen are discussed.

scholarly journals Evidence for Sexual Recombination in Didymella tanaceti Populations, and Their Evolution Over Spring Production in Australian Pyrethrum Fields

2019 ◽  
Vol 109 (1) ◽  
pp. 155-168 ◽  
Author(s):  
Tamieka L. Pearce ◽  
Jason B. Scott ◽  
Stacey J. Pilkington ◽  
Sarah J. Pethybridge ◽  
Frank S. Hay
Keyword(s):  
Genetic Diversity ◽  
Mating Type ◽  
Sampling Period ◽  
Genotypic Diversity ◽  
Tan Spot ◽  
Late Winter ◽  
Linkage Equilibrium ◽  
Mating Types ◽  
Isolation Frequency ◽  
Sexual Recombination

Tan spot, caused by Didymella tanaceti, is one of the most important foliar diseases affecting pyrethrum in Tasmania, Australia. Population dynamics, including mating-type ratios and genetic diversity of D. tanaceti, was characterized within four geographically separated fields in both late winter and spring 2012. A set of 10 microsatellite markers was developed and used to genotype 774 D. tanaceti isolates. Isolates were genotypically diverse, with 123 multilocus genotypes (MLG) identified across the four fields. Fifty-eight MLG contained single isolates and Psex analysis estimated that, within many of the recurrent MLG, there were multiple clonal lineages derived from recombination. Isolates of both mating types were at a 1:1 ratio following clone correction in each field at each sampling period, which was suggestive of sexual recombination. No evidence of genetic divergence of isolates of each mating type was identified, indicating admixture within the population. Linkage equilibrium in two of the four field populations sampled in late winter could not be discounted following clone correction. Evaluation of temporal changes in gene and genotypic diversity identified that they were both similar for the two sampling periods despite an increased D. tanaceti isolation frequency in spring. Genetic differentiation was similar in populations sampled between the two sampling periods within fields or between fields. These results indicated that sexual reproduction may have contributed to tan spot epidemics within Australian pyrethrum fields and has contributed to a genetically diverse D. tanaceti population.

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