Increased Genotypic Diversity via Migration and Possible Occurrence of Sexual Reproduction ofPhytophthora infestansin Poland

1994 ◽  
Vol 84 (2) ◽  
pp. 201 ◽  
Author(s):  
Ludwik S. Sujkowski
Keyword(s):  
Sexual Reproduction ◽  
Genotypic Diversity

scholarly journals Occurrence and Survival of Apothecia of the Eyespot Pathogens Oculimacula acuformis and O. yallundae on Wheat Stubble in the U.S. Pacific Northwest

Plant Disease ◽  
2016 ◽  
Vol 100 (5) ◽  
pp. 991-995 ◽  
Author(s):  
D. I. Vera ◽  
T. D. Murray
Keyword(s):  
Winter Wheat ◽  
Sexual Reproduction ◽  
Pacific Northwest ◽  
Soil Surface ◽  
Genotypic Diversity ◽  
The United States ◽  
The Pacific ◽  
Wheat Stubble ◽  
Oculimacula Yallundae

Eyespot is a chronic disease of wheat caused by Oculimacula yallundae and O. acuformis that results in premature ripening of grain, lodging, and reduced grain yield. Discovery of the sexual stage of these Oculimacula spp. in the Pacific Northwest (PNW) of the United States is relatively recent and the role of apothecia in the epidemiology of eyespot is unclear. Our goals were to determine whether and when apothecia of these Oculimacula spp. are found in the PNW, and monitor their ability to survive over summer and over winter. Seventy-three harvested commercial wheat fields in Idaho, Oregon, and Washington were surveyed for apothecia during spring and fall 2012 and spring 2013. Apothecia of both species were found in both spring and fall in 19% of fields. Apothecia survived on straw placed on the soil surface over the summer but not the winter. This is the first report of O. yallundae apothecia in commercial wheat fields in the PNW. Occurrence of apothecia in spring and fall demonstrates that sexual reproduction of both species occurs regularly in the PNW and at a time when ascospores could serve as primary inoculum for infection of winter wheat. Results of this study are consistent with previous population genetic studies that found high genotypic diversity of both eyespot pathogens in winter wheat fields and provides a baseline for understanding the influence of sexual reproduction on population dynamics and genetics of both pathogens.

scholarly journals Mating-Type Distribution and Genetic Diversity of Cercospora sojina Populations on Soybean from Arkansas: Evidence for Potential Sexual Reproduction

2013 ◽  
Vol 103 (10) ◽  
pp. 1045-1051 ◽  
Author(s):  
Hun Kim ◽  
Annakay D. Newell ◽  
Robyn G. Cota-Sieckmeyer ◽  
John C. Rupe ◽  
Ahmad M. Fakhoury ◽  
...  
Keyword(s):  
Sexual Reproduction ◽  
Mating Type ◽  
Spatial Scales ◽  
Genotypic Diversity ◽  
The United States ◽  
Economic Losses ◽  
Mating Types ◽  
Cercospora Sojina ◽  
Single Leaf ◽  
Corrected Data

Cercospora sojina causes frogeye leaf spot of soybean, which can cause serious economic losses in the United States. In this study, 132 C. sojina isolates were collected from six fields (from two counties, Cross and Crawford) in Arkansas. To determine mating type, a multiplex polymerase chain reaction assay was developed with primers specific for C. sojina. Of the 132 isolates, 68 isolates had the MAT1-1-1 idiomorph and 64 isolates had the MAT1-2 idiomorph; no isolates possessed both idiomorphs. Both mating types were present in a variety of spatial scales, including separate lesions on individual leaves. Clone-corrected data from eight microsatellites indicated that mating-type loci were present in approximately equal proportions in all populations analyzed, which suggests that Arkansas populations of C. sojina are undergoing cryptic sexual reproduction. All six populations evaluated had high genotypic diversity of 26 to 79%. In addition, among strains isolated from a single leaf, multiple and distinct haplotypes were associated with both mating types, supporting the hypothesis that sexual reproduction occurs within the populations. Most populations showed significant gametic disequilibrium but levels of disequilibrium were relatively low, particularly in populations from Crawford County. A low differentiation index (GST) was observed for all simple-sequence repeat markers across all populations. Furthermore, the value of G statistics between populations suggests that significant genetic exchange exists among the populations. Taken together, these results demonstrate that C. sojina populations from Arkansas are genetically diverse and most likely undergoing sexual reproduction.

scholarly journals High genotypic diversity of the reef-building coral Porites lobata (Scleractinia: Poritidae) in Isla del Coco National Park, Costa Rica

2017 ◽  
pp. 279-292
Author(s):  
Jennifer N. Boulay ◽  
Jorge Cortés ◽  
Jaime Nivia-Ruiz ◽  
Iliana B. Baums
Keyword(s):  
Costa Rica ◽  
Sexual Reproduction ◽  
Colony Size ◽  
National Park ◽  
Southern Oscillation ◽  
Genotypic Diversity ◽  
Physical Structure ◽  
Ecosystem Recovery ◽  
Relative Contribution ◽  
Porites Lobata

The isolated Isla del Coco experiences periodic, extreme disturbances which devastate coral reefs surrounding the island. Scleractinian corals build the physical structure of the reef therefore ecosystem recovery relies on coral species recovery. Coral recruits can be of sexual or asexual origin, and the relative success of the two recruit types influences the speed and spread of recovery processes. Here we focus on the massive coral, Porites lobata, because it is the main reef-builder around Isla del Coco to describe the relative contribution of asexual and sexual recruits to population maintenance. P. lobata samples were collected using a spatially explicit random sampling design in three plots at Isla del Coco: Punta Ulloa (n=17), Bahía Weston (n=20) and Punta María (n=20) and samples were genotyped with 11 microsatellite markers. Additional sampling was conducted at three “coastal” sites near the Costa Rican mainland (Isla del Caño Biological Reserve): Caño1 (n=8), Caño2 (n=10), Caño5 (n=11) to compare the contributions of asexual and sexual recruits at Isla del Coco sites to coastal sites. Isla del Coco sites were characterized by small colony size (>60% of colonies <0.5m2) and high sexual reproduction. Sites were either mostly or entirely sexual,consisting of only unique genotypes (NG/N= 0.90-1.00; G O/GE=0.83-1.00; D=0.99-1.00). Although there were no significant differences in genetic diversity (number of alleles per locus, number of private alleles) or colony size between Isla del Coco and the coastal sites, the coastal sites exhibited a greater range of genotypic diversity from moderately asexual (NG/N=0.5; GO/GE=0.36; D=0.8) to purely sexual (NG/N=1.0; GO/GE=1.0; D=1.0). The mode of asexual reproduction in P. lobata is likely fragmentation of adult colonies rather than asexual larval production because ramets of P. lobata occurred close together and asexually produced larvae have not been reported in gonochoric broadcast spawners like P. lobata. Frequent sexual reproduction at Isla del Coco National Park might represent a resource for rapid recovery following extreme El Niño-Southern Oscillation (ENSO) disturbance events. In contrast, larger, asexuallyproduced fragments rather than smaller, sexually-produced larvae appear to have the advantage at some coastal sites. The high frequency of sexual reproduction at Isla del Coco indicates that not only are sexual partners available but also current conditions are favorable for the delivery of larvae and the rate of predation on small larval recruits must be moderate. Citation: Boulay, J.N., J. Cortés, J. Nivia-Ruiz & I.B. Baums. 2012. High genotypic diversity of the reef-building coral Porites lobata (Scleractinia: Poritidae) in Isla del Coco National Park, Costa Rica. Rev. Biol. Trop. 60 (Suppl. 3): 279-292. Epub 2012 Dec 01.

scholarly journals Sexual reproduction vs. clonal propagation in the recovery of a seagrass meadow after an extreme weather event

2019 ◽  
Vol 83 (4) ◽  
pp. 357 ◽  
Author(s):  
Diogo Paulo ◽  
Onno Diekmann ◽  
Ana Alexandra Ramos ◽  
Filipe Alberto ◽  
Ester Alvares Serrão
Keyword(s):  
Sexual Reproduction ◽  
Clonal Propagation ◽  
Seagrass Meadow ◽  
Genotypic Diversity ◽  
Weather Event ◽  
Winter Storms ◽  
Relative Contribution ◽  
Sexual Propagation ◽  
Seedling Germination

Marine flowering plants can reproduce sexually and clonally, and the relative contribution of these two modes can be dependent on the environmental conditions. Zostera marina, a seagrass widely distributed in the northern hemisphere, can form annual and perennial meadows with different proportions of sexual versus clonal propagation depending on the environmental disturbance regime. We study the hypothesis that the contribution of sexual propagation varies during the recovery of a seagrass meadow. In this case study, we compare the proportion of sexual versus clonal propagation of a perennial Z. marina meadow before its disappearance due to winter storms and after recovery. Before disturbance, genotypic diversity was high, indicating frequent sexual reproduction events likely to create an abundant seed bank. Seedling germination allowed the population to recover after the extreme disturbance. As months passed, seedlings became rare and finally absent, giving place to adult shoots. In an advanced stage of colonization, the shoots colonized the area by vegetative growth, which lowered the genotypic diversity. Despite this reduction over time, the genotypic diversity of the new meadow is still high, demonstrating the importance of sexual reproduction in meadow recovery and persistence.

scholarly journals The Population Genetics of Clonal and Partially Clonal Diploids

Genetics ◽  
2003 ◽  
Vol 164 (4) ◽  
pp. 1635-1644 ◽  
Author(s):  
François Balloux ◽  
Laurent Lehmann ◽  
Thierry de Meeûs
Keyword(s):  
Population Genetics ◽  
Sexual Reproduction ◽  
Extreme Values ◽  
Genotypic Diversity ◽  
Clonal Reproduction ◽  
Effective Population ◽  
Multiple Loci ◽  
Subdivided Population ◽  
Asexual Populations ◽  
Neutral Markers

Abstract The consequences of variable rates of clonal reproduction on the population genetics of neutral markers are explored in diploid organisms within a subdivided population (island model). We use both analytical and stochastic simulation approaches. High rates of clonal reproduction will positively affect heterozygosity. As a consequence, nearly twice as many alleles per locus can be maintained and population differentiation estimated as FST value is strongly decreased in purely clonal populations as compared to purely sexual ones. With increasing clonal reproduction, effective population size first slowly increases and then points toward extreme values when the reproductive system tends toward strict clonality. This reflects the fact that polymorphism is protected within individuals due to fixed heterozygosity. Contrarily, genotypic diversity smoothly decreases with increasing rates of clonal reproduction. Asexual populations thus maintain higher genetic diversity at each single locus but a lower number of different genotypes. Mixed clonal/sexual reproduction is nearly indistinguishable from strict sexual reproduction as long as the proportion of clonal reproduction is not strongly predominant for all quantities investigated, except for genotypic diversities (both at individual loci and over multiple loci).

Life cycle of Spirogyra decimina var. juergensii (Kütz.) O.V. Petlovany from Lake Baikal

2018 ◽  
pp. 1-7
Author(s):  
Ekaterina A. Volkova
Keyword(s):  
Life Cycle ◽  
Sexual Reproduction ◽  
Lake Baikal

Identification of Spirogyra species is based on the morphology of the fertile specimens. This work provides characteristics of growth and the time of reproduction of Spirogyra decimina var. juergensii in Lake Baikal and describes sexual reproduction and conditions for germination of new filaments of this species isolated from the lake.

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