Plant breeding system, genetic structure and conservation of genetic diversity

Abstract Studies of patterns of genetic diversity, genetic structure and ecological data across geographical ranges of species allow us to test hypotheses about the evolutionary responses of organisms to fluctuations in habitat connectivity and availability. Here we present a study aiming to assess genetic diversity, population structure and breeding system across the geographical distribution of a subtropical epiphyte, Tillandsia aeranthos (Bromeliaceae), endemic to the Plata River basin (Pampa biome). Seven nuclear microsatellite markers were genotyped in 203 individuals from 13 localities across Brazil and Argentina and 14 plastid regions were sequenced for a subset of the individuals. Additionally, we performed controlled pollination experiments to discuss correlations between breeding system, genetic diversity and structure in the species. Nuclear diversity levels were high (HE = 0.806, HO = 0.745, allelic richness = 5.860) with no haplotype differentiation detected (c. 9 kpb sequenced). Bayesian assignment analysis, supported by principal coordinate analysis and analysis of molecular variance, show low genetic structure across the studied area (FST = 0.031, P < 0.001). Controlled pollination experiments indicated complete self-incompatibility in all localities analysed. Our results show effective gene flow maintaining low genetic structure between localities for T. aeranthos across an extensive area in the Pampa.

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Reproductive development and genetic structure of the mycoheterotrophic orchid Pogoniopsis schenckii Cogn.

BMC Plant Biology ◽

10.1186/s12870-021-03118-y ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Mariana Ferreira Alves ◽

Fabio Pinheiro ◽

Carlos Eduardo Pereira Nunes ◽

Francisco Prosdocimi ◽

Deise Schroder Sarzi ◽

...

Keyword(s):

Genetic Diversity ◽

Genetic Structure ◽

Breeding System ◽

Embryo Sac ◽

Field Tests ◽

Reproductive Organs ◽

Reproductive Process ◽

Low Genetic Diversity ◽

Genetic Diversity And Structure ◽

Fungal Hyphae

Abstract Background Pogoniopsis schenckii Cogn. is a mycoheterotrophic orchid that can be used as a model to understand the influence of mycoheterotrophy at different stages of the reproductive cycle. We aimed to verify the presence of endophytic and epiphytic fungi at each stage of the reproductive process and investigated how the breeding system may relate to genetic structure and diversity of populations. In this study we performed anatomical and ultrastructural analyses of the reproductive organs, field tests to confirm the breeding system, and molecular analysis to assess genetic diversity and structure of populations. Results During the development of the pollen grain, embryo sac and embryogenesis, no fungal infestation was observed. The presence of endophytic fungal hyphae was observed just within floral stems and indehiscent fruit. Beyond assuring the presence of fungus that promote seed germination, specific fungi hyphae in the fruit may affect other process, such as fruit ripening. As other mycoheterotrophic orchids, P. schenckii is autogamous, which may explain the low genetic diversity and high genetic structure in populations. Conclusions We discuss an interesting interaction: fungal hyphae in the indehiscent fruit. These fungal hyphae seem to play different roles inside fruit tissues, such as acting in the fruit maturation process and increasing the proximity between fungi and plant seeds even before dispersion occurs. As other mycoheterotrophic orchids, P. schenckii is autogamous, which may explain the low genetic diversity and high genetic structure in populations. Altogether, our findings provide important novel information about the mechanisms shaping ecology and evolution of fragmented populations of mycoheterotrophic plant.

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Genetic diversity and genetic structure of the rare and endangered species, Primula ranunculoides

Biodiversity Science ◽

10.3724/sp.j.1003.2013.09098 ◽

2014 ◽

Vol 21 (5) ◽

pp. 601-609

Author(s):

Wang Deyun ◽

Peng Jie ◽

Chen Yajing ◽

Lü Guosheng ◽

Zhang Xiaoping ◽

...

Keyword(s):

Genetic Diversity ◽

Genetic Structure ◽

Endangered Species ◽

Rare And Endangered Species ◽

Rare And Endangered

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The Patterns and Puzzles of Genetic Diversity of Endangered Freshwater Mussel Unio crassus Philipsson, 1788 Populations from Vistula and Neman Drainages (Eastern Central Europe)

Life ◽

10.3390/life10070119 ◽

2020 ◽

Vol 10 (7) ◽

pp. 119

Author(s):

Adrianna Kilikowska ◽

Monika Mioduchowska ◽

Anna Wysocka ◽

Agnieszka Kaczmarczyk-Ziemba ◽

Joanna Rychlińska ◽

...

Keyword(s):

Genetic Diversity ◽

Genetic Structure ◽

Spatial Scales ◽

Freshwater Mussel ◽

Its Region ◽

Strong Relationship ◽

Mantel Test ◽

Freshwater Ecosystems ◽

Hierarchical Organization ◽

Anthropogenic Factors

Mussels of the family Unionidae are important components of freshwater ecosystems. Alarmingly, the International Union for Conservation of Nature and Natural Resources Red List of Threatened Species identifies almost 200 unionid species as extinct, endangered, or threatened. Their decline is the result of human impact on freshwater habitats, and the decrease of host fish populations. The Thick Shelled River Mussel Unio crassus Philipsson, 1788 is one of the examples that has been reported to show a dramatic decline of populations. Hierarchical organization of riverine systems is supposed to reflect the genetic structure of populations inhabiting them. The main goal of this study was an assessment of the U. crassus genetic diversity in river ecosystems using hierarchical analysis. Different molecular markers, the nuclear ribosomal internal transcribed spacer ITS region, and mitochondrial DNA genes (cox1 and ndh1), were used to examine the distribution of U. crassus among-population genetic variation at multiple spatial scales (within rivers, among rivers within drainages, and between drainages of the Neman and Vistula rivers). We found high genetic structure between both drainages suggesting that in the case of the analyzed U. crassus populations we were dealing with at least two different genetic units. Only about 4% of the mtDNA variation was due to differences among populations within drainages. However, comparison of population differentiation within drainages for mtDNA also showed some genetic structure among populations within the Vistula drainage. Only one haplotype was shared among all Polish populations whereas the remainder were unique for each population despite the hydrological connection. Interestingly, some haplotypes were present in both drainages. In the case of U. crassus populations under study, the Mantel test revealed a relatively strong relationship between genetic and geographical distances. However, in detail, the pattern of genetic diversity seems to be much more complicated. Therefore, we suggest that the observed pattern of U. crassus genetic diversity distribution is shaped by both historical and current factors i.e. different routes of post glacial colonization and history of drainage systems, historical gene flow, and more recent habitat fragmentation due to anthropogenic factors.

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Impact of cyclones on hard coral and metapopulation structure, connectivity and genetic diversity of coral reef fish

Coral Reefs ◽

10.1007/s00338-021-02096-9 ◽

2021 ◽

Author(s):

Gabriele Gerlach ◽

Philipp Kraemer ◽

Peggy Weist ◽

Laura Eickelmann ◽

Michael J. Kingsford

Keyword(s):

Genetic Diversity ◽

Coral Reef ◽

Genetic Structure ◽

Reef Fish ◽

Coral Reef Fish ◽

Population Genetic Study ◽

Hard Coral ◽

Great Loss ◽

Metapopulation Structure ◽

The Impact

AbstractCyclones have one of the greatest effects on the biodiversity of coral reefs and the associated species. But it is unknown how stochastic alterations in habitat structure influence metapopulation structure, connectivity and genetic diversity. From 1993 to 2018, the reefs of the Capricorn Bunker Reef group in the southern part of the Great Barrier Reef were impacted by three tropical cyclones including cyclone Hamish (2009, category 5). This resulted in substantial loss of live habitat-forming coral and coral reef fish communities. Within 6–8 years after cyclones had devastated, live hard corals recovered by 50–60%. We show the relationship between hard coral cover and the abundance of the neon damselfish (Pomacentrus coelestis), the first fish colonizing destroyed reefs. We present the first long-term (2008–2015 years corresponding to 16–24 generations of P. coelestis) population genetic study to understand the impact of cyclones on the meta-population structure, connectivity and genetic diversity of the neon damselfish. After the cyclone, we observed the largest change in the genetic structure at reef populations compared to other years. Simultaneously, allelic richness of genetic microsatellite markers dropped indicating a great loss of genetic diversity, which increased again in subsequent years. Over years, metapopulation dynamics were characterized by high connectivity among fish populations associated with the Capricorn Bunker reefs (2200 km2); however, despite high exchange, genetic patchiness was observed with annual strong genetic divergence between populations among reefs. Some broad similarities in the genetic structure in 2015 could be explained by dispersal from a source reef and the related expansion of local populations. This study has shown that alternating cyclone-driven changes and subsequent recovery phases of coral habitat can greatly influence patterns of reef fish connectivity. The frequency of disturbances determines abundance of fish and genetic diversity within species.

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Insights from putatively neutral EST-SSR markers on the population genetic structure and genetic diversity of the Qinghai-Tibetan Plateau endemic Medicago archiducis-nicolai Sirjaev

Genetic Resources and Crop Evolution ◽

10.1007/s10722-021-01147-y ◽

2021 ◽

Author(s):

Yingfang Wang ◽

Yingfang Shen ◽

Demei Liu ◽

Ruijuan Liu ◽

Haiqing Wang

Keyword(s):

Genetic Diversity ◽

Genetic Structure ◽

Tibetan Plateau ◽

Ssr Markers ◽

Population Genetic Structure ◽

Population Genetic

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Effects of habitat structure and land-use intensity on the genetic structure of the grasshopper species Chorthippus parallelus

Royal Society Open Science ◽

10.1098/rsos.140133 ◽

2014 ◽

Vol 1 (2) ◽

pp. 140133 ◽

Cited By ~ 4

Author(s):

Kerstin R. Wiesner ◽

Jan Christian Habel ◽

Martin M. Gossner ◽

Hugh D. Loxdale ◽

Günter Köhler ◽

...

Keyword(s):

Genetic Diversity ◽

Land Use ◽

Genetic Structure ◽

Sampling Site ◽

Land Use Intensity ◽

Habitat Size ◽

Grasshopper Species ◽

Chorthippus Parallelus ◽

Landscape Characteristics ◽

Local Populations

Land-use intensity (LUI) is assumed to impact the genetic structure of organisms. While effects of landscape structure on the genetics of local populations have frequently been analysed, potential effects of variation in LUI on the genetic diversity of local populations have mostly been neglected. In this study, we used six polymorphic microsatellites to analyse the genetic effects of variation in land use in the highly abundant grasshopper Chorthippus parallelus . We sampled a total of 610 individuals at 22 heterogeneous grassland sites in the Hainich-Dün region of Central Germany. For each of these grassland sites we assessed habitat size, LUI (combined index of mowing, grazing and fertilization), and the proportion of grassland adjoining the sampling site and the landscape heterogeneity (the latter two factors within a 500 m buffer zone surrounding each focal site). We found only marginal genetic differentiation among all local populations and no correlation between geographical and genetic distance. Habitat size, LUI and landscape characteristics had only weak effects on most of the parameters of genetic diversity of C. parallelus ; only expected heterozygosity and the grasshopper abundances were affected by interacting effects of LUI, habitat size and landscape characteristics. The lack of any strong relationships between LUI, abundance and the genetic structure might be due to large local populations of the species in the landscape, counteracting local differentiation and potential genetic drift effects.

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The spatial genetic structure of bank vole (Myodes glareolus) and yellow-necked mouse (Apodemus flavicollis) populations: The effect of distance and habitat barriers

Animal Biology ◽

10.1163/157075609x437691 ◽

2009 ◽

Vol 59 (2) ◽

pp. 169-187 ◽

Cited By ~ 19

Author(s):

Michal Kozakiewicz ◽

Alicja Gryczyńska–Siemiątkowska ◽

Hanna Panagiotopoulou ◽

Anna Kozakiewicz ◽

Robert Rutkowski ◽

...

Keyword(s):

Genetic Diversity ◽

Genetic Structure ◽

Bank Vole ◽

Microsatellite Loci ◽

Myodes Glareolus ◽

Apodemus Flavicollis ◽

Island Populations ◽

Local Populations ◽

Bank Vole Myodes Glareolus ◽

Yellow Necked Mouse

AbstractHabitat barriers are considered to be an important factor causing the local reduction of genetic diversity by dividing a population into smaller sections and preventing gene flow between them. However, the “barrier effect” might be different in the case of different species. The effect of geographic distance and water barriers on the genetic structure of populations of two common rodent species – the yellow-necked mouse (Apodemus flavicollis) and the bank vole (Myodes glareolus) living in the area of a lake (on its islands and on two opposite shores) was investigated with the use of microsatellite fragment analysis. The two studied species are characterised by similar habitat requirements, but differ with regard to the socio-spatial structure of the population, individual mobility, capability to cross environmental barriers, and other factors. Trapping was performed for two years in spring and autumn in north-eastern Poland (21°E, 53°N). A total of 160 yellow-necked mouse individuals (7 microsatellite loci) and 346 bank vole individuals (9 microsatellite loci) were analysed. The results of the differentiation analyses (FST and RST) have shown that both the barrier which is formed by a ca. 300 m wide belt of water (between the island and the mainland) and the actual distance of approximately 10 km in continuous populations are sufficient to create genetic differentiation within both species. The differences between local populations living on opposite lake shores are the smallest; differences between any one of them and the island populations are more distinct. All of the genetic diversity indices (the mean number of alleles, mean allelic richness, as well as the observed and expected heterozygosity) of the local populations from the lakeshores were significantly higher than of the small island populations of these two species separated by the water barrier. The more profound “isolation effect” in the case of the island populations of the bank vole, in comparison to the yellow-necked mouse populations, seems to result not only from the lower mobility of the bank vole species, but may also be attributed to other differences in the animals' behaviour.

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