scholarly journals Genetic Differentiation and Mixed Reproductive Strategies in the Northern Corn Leaf Blight Pathogen Setosphaeria turcica From Sweet Corn in Fujian Province, China

2021 ◽  
Vol 12 ◽  
Author(s):  
Yuli Dai ◽  
Lin Gan ◽  
Chengzhong Lan ◽  
Xuesong Lu ◽  
Xiujuan Yang ◽  
...  
Keyword(s):  
Population Genetics ◽  
Population Structure ◽  
Genetic Differentiation ◽  
Mating Type ◽  
Reproductive Strategies ◽  
Sweet Corn ◽  
Mating Types ◽  
Fujian Province ◽  
Northern Corn Leaf Blight ◽  
Corn Leaf Blight

The northern corn leaf blight (NCLB) pathogen Setosphaeria turcica (Luttrell) Leonard and Suggs is one of the main biotic constraints on sweet corn (Zea mays L.) yield and quality in Fujian Province, China. Currently, however, there is comparatively little information available regarding the distribution of mating types, population genetics, and reproductive strategies of this pathogen in Fujian. In this study, we investigated the distribution of mating types and population genetics of 117 isolates of S. turcica collected from seven of the main sweet corn-growing regions in Fujian Province, based on multiple polymerase chain reaction analyses using two mating type-specific primer pairs and 11 inter-simple sequence repeat markers. Furthermore, we examined the mode of reproduction of Fujian S. turcica populations. Both MAT1-1 and MAT1-2 mating types were detected throughout all seven sampling locations. The majority of MAT1-2 isolates were detected from Dongyou, Jian’ou, Pingnan, Songxi, and Longyan, whereas a large proportion of the detected MAT1-1 isolates were among those collected from Dongfeng and Nanjing. Furthermore, we detected five shared multi-locus haplotypes among S. turcica isolates from Dongyou, Jian’ou, Pingnan, Nanjing, and Songxi, whereas no shared haplotypes were observed between the Dongfeng (or Longyan) population and these five populations. Pairwise comparisons of the indices ΦPT and Nm, and population structure and principal coordinate analyses indicated genetic differentiation between both the regional and the mating type populations of S. turcica in Fujian. The skewed mating type ratio associated with low a haplotypic diversity and evident linkage disequilibrium reveals a mixed reproductive strategy for S. turcica populations in Fujian Province. The findings of this study advance our current understanding of the genetic diversity, population structure, and reproductive strategies of S. turcica populations infecting sweet corn in Fujian Province, and will potentially contribute to further resistance breeding efforts.

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 Population Structure, Pathogenicity, and Mating Type Distribution of Magnaporthe oryzae Isolates from East Africa

2015 ◽  
Vol 105 (8) ◽  
pp. 1137-1145 ◽  
Author(s):  
Geoffrey Onaga ◽  
Kerstin Wydra ◽  
Birger Koopmann ◽  
Yakouba Séré ◽  
Andreas von Tiedemann
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Genetic Differentiation ◽  
East Africa ◽  
Mating Type ◽  
Magnaporthe Oryzae ◽  
Geographic Origin ◽  
The Philippines ◽  
Genetic Population ◽  
Principal Coordinates

Rice blast, caused by Magnaporthe oryzae, is one of the emergent threats to rice production in East Africa (EA), where little is known about the population genetics and pathogenicity of this pathogen. We investigated the genetic diversity and mating type (MAT) distribution of 88 isolates of M. oryzae from EA and representative isolates from West Africa (WA) and the Philippines (Asia) using amplified fragment length polymorphism markers and mating-type-specific primer sets. In addition, the aggressiveness of each isolate was evaluated by inoculating on the susceptible Oryza sativa indica ‘Co39’, scoring the disease severity and calculating the disease progress. Hierarchical analysis of molecular variance revealed a low level of genetic differentiation at two levels (FST 0.12 and FCT 0.11). No evidence of population structure was found among the 65 isolates from EA, and gene flow among EA populations was high. Moreover, pairwise population differentiation (GST) in EA populations ranged from 0.03 to 0.04, suggesting that >96% of genetic variation is derived from within populations. However, the populations from Asia and WA were moderately differentiated from EA ones. The spatial analysis of principal coordinates and STRUCTURE revealed overlapping between individual M. oryzae isolates from EA, with limited distinctness according to the geographic origin. All the populations were clonal, given the positive and significant index of association (IA) and standardized index of association (rd), which indicates a significant (P < 0.001) departure from panmixia (IA and rd = 0). Both MAT1-1 and MAT1-2 were detected. However, MAT1-1 was more prevalent than MAT1-2. Pathogenicity analysis revealed variability in aggressiveness, suggesting a potential existence of different races. Our data suggest that either M. oryzae populations from EA could be distributed as a single genetic population or gene flow is exerting a significant influence, effectively swamping the action of selection. This is the first study of genetic differentiation of rice-infecting M. oryzae strains from EA, and may guide further studies on the pathogen as well as resistance breeding efforts.

scholarly journals Quantitative Trait Loci in Sweet Corn Associated with Partial Resistance to Stewart's Wilt, Northern Corn Leaf Blight, and Common Rust

2001 ◽  
Vol 91 (3) ◽  
pp. 293-300 ◽  
Author(s):  
A. F. Brown ◽  
J. A. Juvik ◽  
J. K. Pataky
Keyword(s):  
Quantitative Trait Loci ◽  
Quantitative Trait ◽  
Partial Resistance ◽  
Sweet Corn ◽  
Phenotypic Variability ◽  
Leaf Blight ◽  
Northern Corn Leaf Blight ◽  
Trait Loci ◽  
Stewart's Wilt ◽  
Corn Leaf Blight

Partial resistance to Stewart's wilt (Erwina stewartii, syn. Pantoea stewartii), northern corn leaf blight (NCLB) (Exserohilum turcicum), and common rust (Puccinia sorghi) was observed in an F2:3 population developed from a cross between the inbred sweet corn lines IL731a and W6786. The objective of this study was to identify quantitative trait loci (QTL) associated with partial resistance using restriction fragment length polymorphic markers. Phenotypic data were collected for 2 years for Stewart's wilt, NCLB, and common rust but, due to significant family-environment interaction, analysis was conducted individually on data from each year. In 2 years of evaluation for the three diseases, a total of 33 regions in the maize genome were associated with partial resistance describing from 5.9 to 18% of the total phenotypic variability. Of six regions common in both years, three were associated with partial resistance to Stewart's wilt (chromosomes 4:07, 5:03, and 6:04), one was associated with NCLB (chromosome 9:05), and two were associated with common rust (chromosomes 2:04 and 3:04). The rust QTL on 3S mapped to within 20 cM of the rp3 locus and explained 17.7% of the phenotypic variability. Some of the QTL associated with partial resistance to the three diseases have been reported previously, and some are described here for the first time. Results suggest it may be possible to consolidate QTL from various elite backgrounds in a manner analogous to the pyramiding of major resistance genes. We also report here on two QTL associated with anthocyanin production on chromosomes 10:6 and 5:03 in the general location of the a2 gene.

scholarly journals Inherent population structure determines the importance of filtering parameters for reduced representation sequencing analyses

2020 ◽  
Author(s):  
D. Selechnik ◽  
M.F. Richardson ◽  
M.K. Hess ◽  
A.S. Hess ◽  
K.G. Dodds ◽  
...  
Keyword(s):  
Population Genetics ◽  
Population Structure ◽  
Genetic Differentiation ◽  
Call Rate ◽  
Wild Populations ◽  
Intrinsic Properties ◽  
Reduced Representation ◽  
Study Population ◽  
Low Levels ◽  
Reduced Representation Sequencing

AbstractAs technological advancements enhance our ability to study population genetics, we must understand how the intrinsic properties of our datasets influence the decisions we make when designing experiments. Filtering parameter thresholds, such as call rate and minimum minor allele frequency (MAF), are known to affect inferences of population structure in reduced representation sequencing (RRS) studies. However, it is unclear to what extent the impacts of these parameter choices vary across datasets. Here, we reviewed literature on filtering choices and levels of genetic differentiation across RRS studies on wild populations to highlight the diverse approaches that have been used. Next, we hypothesized that choices in filtering thresholds would have the greatest impact when analyzing datasets with low levels of genetic differentiation between populations. To test this hypothesis, we produced seven simulated RRS datasets with varying levels of population structure, and analyzed them using four different combinations of call rate and MAF. We performed the same analysis on two empirical RRS datasets (low or high population structure). Our simulated and empirical results suggest that the effects of filtering choices indeed vary based on inherent levels of differentiation: specifically, choosing stringent filtering choices was important to detect distinct populations that were slightly differentiated, but not those that were highly differentiated. As a result, experimental design and analysis choices need to consider attributes of each specific dataset. Based on our literature review and analyses, we recommend testing a range of filtering parameter choices, and presenting all results with clear justification for ultimate filtering decisions used in downstream analyses.

Population genetics of the people of Iran II. Genetic differentiation and population structure

1992 ◽  
Vol 7 (3) ◽  
pp. 11-18 ◽  
Author(s):  
S. S. Papiha ◽  
P. Amirshahi ◽  
E. Sunderland ◽  
D. D. Farhud ◽  
S. H. Tavakoli ◽  
...  
Keyword(s):  
Population Genetics ◽  
Population Structure ◽  
Genetic Differentiation ◽  
The People

scholarly journals Development of microsatellite loci and population genetics in the bumblebee catfish species Pseudopimelodus atricaudus and Pseudopimelodus magnus (Siluriformes: Pseudopimelodidae)

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
José David Rangel-Medrano ◽  
Edna Judith Márquez
Keyword(s):  
Genetic Diversity ◽  
Population Genetics ◽  
Population Structure ◽  
Genetic Differentiation ◽  
River Basin ◽  
Microsatellite Loci ◽  
Population Genetic ◽  
High Genetic Diversity ◽  
The Family ◽  
The Mean

ABSTRACT The Neotropical freshwater catfish Pseudopimelodus atricaudus and Pseudopimelodus magnus are two recently discovered species endemic to the Colombian Magdalena-Cauca River basin. In this study, a set of 13 microsatellite loci were developed by using next generation sequence technology to assess the genetic diversity and population structure in P. atricaudus and test for cross-species amplification in P. magnus. Both species exhibited high genetic diversity (P. atricaudus: Na: 9.000 - 9.769 alleles/locus, Ho: 0.760 - 0.804, HE: 0.804 - 0.840; P. magnus: Na: 12.8 - 5.4 alleles/locus, Ho: 0.638 - 0.683, HE: 0.747 - 0.755) compared to the mean levels of genetic diversity reported for Neotropical Siluriformes, and lack of genetic differentiation among sampling sites within the Cauca River (P. atricaudus: F’ST=0.013 - 0.017, P > 0.05, D’est= -0.004 - 0.023, P > 0.05; P. magnus: F’ST= 0.031, P= 0.055; D’est= 0.045, P= 0.058). This work is the first insight on the diversity and the population genetics of species of the family Pseudopimelodidae and provides a framework to further population genetic and conservation analyses needed in this poorly studied family at the microevolutionary level.

scholarly journals Managing Foliar Diseases of Processing Sweet Corn in New York with Strobilurin Fungicides

Plant Disease ◽  
2010 ◽  
Vol 94 (2) ◽  
pp. 213-220 ◽  
Author(s):  
D. A. Shah ◽  
H. R. Dillard
Keyword(s):  
New York ◽  
Disease Severity ◽  
Sweet Corn ◽  
Cost Effective ◽  
Field Trials ◽  
Leaf Blight ◽  
Foliar Disease ◽  
Northern Corn Leaf Blight ◽  
Strobilurin Fungicides ◽  
Corn Leaf Blight

Processing sweet corn (Zea mays) growers in New York are more concerned about the cost effectiveness of fungicide use against foliar fungal diseases (common rust and Northern corn leaf blight) and less about whether such sprays will reduce disease intensity. To address this concern, field trials were done in 2006 and 2007 with three processing sweet corn hybrids (Jubilee, Bold, and GH 9597) that differed in susceptibility to common rust and Northern corn leaf blight, and two strobilurin fungicides (azoxystrobin and pyraclostrobin). Single strobilurin applications were applied in response to foliar disease severity thresholds of 1, 10, and 20%. Single fungicide applications did reduce foliar disease severities. Applications were most cost effective when made in response to the 1 and 10% foliar severity thresholds, and generally only in the susceptible hybrid Bold. Spraying at the 20% severity threshold did reduce final foliar disease severity but was not cost effective. Azoxystrobin and pyraclostrobin were equally effective in disease management. The results suggest that a single application of a strobilurin fungicide against common rust and Northern corn leaf blight can be cost effective for New York processing sweet corn growers when such an application is made before foliar disease severity exceeds 20%.

scholarly journals First Report of Northern Corn Leaf Blight Caused by Setosphaeria turcica on Corn (Zea mays) in Fujian Province, China

Plant Disease ◽  
2017 ◽  
Vol 101 (5) ◽  
pp. 831
Author(s):  
N. N. Shi ◽  
Y. X. Du ◽  
H. C. Ruan ◽  
X. J. Yang ◽  
Y. L. Dai ◽  
...  
Keyword(s):  
Zea Mays ◽  
Leaf Blight ◽  
Fujian Province ◽  
Setosphaeria Turcica ◽  
First Report ◽  
Northern Corn Leaf Blight ◽  
Corn Leaf Blight

scholarly journals Quantification of Outcrossing Events in Haploid Fungi Using Microsatellite Markers

2020 ◽  
Vol 6 (2) ◽  
pp. 48
Author(s):  
Dong-Hyeon Lee ◽  
Brenda D. Wingfield ◽  
Jolanda Roux ◽  
Michael J. Wingfield
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
High Frequency ◽  
Reproductive Strategies ◽  
Mating Strategies ◽  
Mating Types ◽  
Ceratocystis Fimbriata ◽  
Mating Type Switching ◽  
High Level

Species in genera of the fungal family Ceratocystidaceae are known to have different mating strategies, including heterothallism and homothallism. Of these, species of Ceratocystis, typified by the pathogen Ceratocystis fimbriata all undergo unidirectional mating-type switching. This implies that the pathogens possess the ability to self, but also to undergo sexual outcrossing between isolates of different mating types. In this study, we extended the recently developed microsatellite-based technique to determine the extent to which outcrossing occurs in ascospore masses of haploid fungi to two field collections of Ceratocystis albifundus. In this way, the role of reproductive strategies in shaping population structure and diversity could be better understood. Results showed that a high frequency of outcrossing occurs in isolates of the pathogen from both non-native and native areas. This explains the high level of genetic diversity previously observed in this population despite the fact that this pathogen has the ability to self.

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