Fine-scale structure within a Trillium maculatum (Liliaceae) population

Botany ◽  
2009 ◽  
Vol 87 (3) ◽  
pp. 223-230 ◽  
Author(s):  
Alana N. Walker ◽  
Stephanie A. Foré ◽  
Beverly Collins
Keyword(s):  
Genetic Diversity ◽  
Life History ◽  
Genetic Structure ◽  
Spatial Genetic Structure ◽  
Vegetative Reproduction ◽  
Flowering Plants ◽  
Life History Stages ◽  
Genetic Diversity And Structure ◽  
Random Expectation ◽  
Perennial Herbs

In long-lived ant-dispersed perennial herbs of mesic forests, interactions among fruiting plants, seed dispersal, and plant mortality over life-history stages can create demographic and genetic structure. We investigated whether there was nonrandom variation in the distributions of individuals and in genetic diversity within and among life-history stages of the forest herb Trillium maculatum Raf. (Liliaceae). In 2002 and 2004, all T. maculatum plants in a 5 m × 5 m plot (1572 and 1379 individuals, respectively) were mapped and classified as seedling, one-leaf, three-leaf nonflowering, or flowering. Spatial distributions of plants within and across life-history stages were tested against random expectation. Allozyme analysis of 262 individuals from three life-history stages was used to assess genetic diversity and structure in 2004. The number of seedlings and the proportion of one-leaf plants differed between years, but the proportions of three-leaf nonflowering and flowering plants remained the same. There was little evidence of vegetative reproduction, but heterozygosity was low and there was evidence of inbreeding. Seedlings were clumped around flowering plants at distances up to 50 cm and one-leaf plants were clumped at distances up to 100 cm. There were no apparent genetic differences among life-history stages, nor any apparent spatial genetic structure among all sampled individuals. These results, like those of other demographic and allozyme studies of Trillium species, can be explained by restricted dispersal and random mortality.

scholarly journals Genetic diversity and structure of Astrocaryum jauari (Mart.) palm in two Amazon river basins

2014 ◽  
Vol 14 (3) ◽  
pp. 166-173 ◽  
Author(s):  
Liliane D. Santos Oliveira ◽  
Santiago L. Ferreyra Ramos ◽  
Maria T. Gomes Lopes ◽  
Gabriel Dequigiovanni ◽  
Elizabeth Ann Veasey ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Genetic Structure ◽  
Microsatellite Loci ◽  
Plant Material ◽  
Spatial Genetic Structure ◽  
River Basins ◽  
Genetic Analyses ◽  
Main River ◽  
Genetic Diversity And Structure

Astrocaryum jauari is a non-domesticated palm that is exploited by poachers. Our objective was to investigate the organization of the geneticdiversity and structure of three A. jauari populations. The study was carried out in the state of Amazonas, between the municipalities of Coari and Manaus. Nine microsatellite loci were used for the genetic analyses. High genetic variation was found, with a mean number of alleles per locus varying from 3.9 to 4.4. The average observed heterozygosity, varying from 0.71 to 0.78, was higher than expected. No spatial genetic structure was detected, since only one cluster was observed. Our results indicate a possible dispersion strategy and suggest that conservation measures of this species should focus mainly on the populations found at the end of the main river (Solimões) where most of the plant material originating from the headwaters of the tributaries of this river is concentrated.

scholarly journals Population genetic structure and connectivity of a riparian selfing herb Caulokaempferia coenobialis at a fine-scale geographic level in subtropical monsoon forest

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Qiong Fu ◽  
Jie Deng ◽  
Min Chen ◽  
Yan Zhong ◽  
Guo-Hui Lu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Population Genetic ◽  
Spatial Genetic Structure ◽  
Complex Mixture ◽  
Conservation Strategies ◽  
Riparian Plants ◽  
Local Populations ◽  
Genetic Diversity And Structure ◽  
Monsoon Forest

Abstract Background Rivers and streams facilitate movement of individuals and their genes across the landscape and are generally recognized as dispersal corridors for riparian plants. Nevertheless, some authors have reported directly contrasting results, which may be attributed to a complex mixture of factors, such as the mating system and dispersal mechanisms of propagules (seed and pollen), that make it difficult to predict the genetic diversity and population structure of riparian species. Here, we investigated a riparian self-fertilizing herb Caulokaempferia coenobialis, which does not use anemochory or zoochory for seed dispersal; such studies could contribute to an improved understanding of the effect of rivers or streams on population genetic diversity and structure in riparian plants. Using polymorphic ISSR and cpDNA loci, we studied the effect at a microgeographic scale of different stream systems (a linear stream, a dendritic stream, and complex transverse hydrological system) in subtropical monsoon forest on the genetic structure and connectivity of C. coenobialis populations across Dinghu Mountain (DH) and Nankun Mountain (NK). Results The results indicate that the most recent haplotypes (DH: H7, H8; NK: h6, h7, h11, h12) are not shared among local populations of C. coenobialis within each stream system. Furthermore, downstream local populations do not accumulate genetic diversity, whether in the linear streamside local populations across DH (H: 0.091 vs 0.136) or the dendritic streamside local populations across NK (H: 0.079 vs 0.112, 0.110). Our results show that the connectivity of local C. coenobialis populations across DH and NK can be attributed to historical gene flows, resulting in a lack of spatial genetic structure, despite self-fertilization. Selfing C. coenobialis can maintain high genetic diversity (H = 0.251; I = 0.382) through genetic differentiation (GST = 0.5915; FST = 0.663), which is intensified by local adaptation and neutral mutation and/or genetic drift in local populations at a microgeographic scale. Conclusion We suggest that streams are not acting as corridors for dispersal of C. coenobialis, and conservation strategies for maintaining genetic diversity of selfing species should be focused on the protection of all habitat types, especially isolated fragments in ecosystem processes.

scholarly journals Conservation genetics of the threatened plant species Physaria filiformis (Missouri bladderpod) reveals strong genetic structure and a possible cryptic species

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247586
Author(s):  
Christine E. Edwards ◽  
Brooke C. Tessier ◽  
Joel F. Swift ◽  
Burgund Bassüner ◽  
Alexander G. Linan ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Genetic Structure ◽  
Plant Species ◽  
Genetic Drift ◽  
Rare Species ◽  
Ex Situ ◽  
Ouachita Mountains ◽  
Genetic Diversity And Structure ◽  
Genetic Clusters

Understanding genetic diversity and structure in a rare species is critical for prioritizing both in situ and ex situ conservation efforts. One such rare species is Physaria filiformis (Brassicaceae), a threatened, winter annual plant species. The species has a naturally fragmented distribution, occupying three different soil types spread across four disjunct geographical locations in Missouri and Arkansas. The goals of this study were to understand: (1) whether factors associated with fragmentation and small population size (i.e., inbreeding, genetic drift or genetic bottlenecks) have reduced levels of genetic diversity, (2) how genetic variation is structured and which factors have influenced genetic structure, and (3) how much extant genetic variation of P. filiformis is currently publicly protected and the implications for the development of conservation strategies to protect its genetic diversity. Using 16 microsatellite markers, we genotyped individuals from 20 populations of P. filiformis from across its geographical range and one population of Physaria gracilis for comparison and analyzed genetic diversity and structure. Populations of P. filiformis showed comparable levels of genetic diversity to its congener, except a single population in northwest Arkansas showed evidence of a genetic bottleneck and two populations in the Ouachita Mountains of Arkansas showed lower genetic variation, consistent with genetic drift. Populations showed isolation by distance, indicating that migration is geographically limited, and analyses of genetic structure grouped individuals into seven geographically structured genetic clusters, with geographic location/spatial separation showing a strong influence on genetic structure. At least one population is protected for all genetic clusters except one in north-central Arkansas, which should therefore be prioritized for protection. Populations in the Ouachita Mountains were genetically divergent from the rest of P. filiformis; future morphological analyses are needed to identify whether it merits recognition as a new, extremely rare species.

scholarly journals Genetic Diversity and Structure of Latvian Tilia cordata Populations

2021 ◽  
Vol 75 (4) ◽  
pp. 261-267
Author(s):  
Dainis Edgars Ruņģis ◽  
Baiba Krivmane
Keyword(s):  
Genetic Diversity ◽  
Microsatellite Markers ◽  
Vegetative Reproduction ◽  
Growth Conditions ◽  
Climatic Conditions ◽  
Tilia Cordata ◽  
High Genetic Diversity ◽  
Genetic Diversity And Structure ◽  
Broadleaf Tree ◽  
Broadleaf Species

Abstract Changing climatic conditions are transforming the ecological and silvicultural roles of broadleaf tree species in northern Europe. Small-leaved lime (Tilia cordata Mill.) is distributed throughout most of Europe, and is a common broadleaf species in Latvia. This species can tolerate a broad range of environmental and ecological conditions, including temperature, water availability, and soil types. The aim of this study was to assess the genetic diversity and differentiation of Latvian T. cordata populations using nuclear microsatellite markers developed for Tilia platyphyllos. After testing of 15 microsatellite markers, Latvian T. cordata samples were genotyped at 14 micro-satellite loci. Latvian T. cordata populations had high genetic diversity, and were not overly isolated from each other, with moderate gene flow between populations. No highly differentiated populations were identified. Vegetative reproduction was identified in most analysed populations, and almost one-third of analysed individuals are of clonal origin. T. cordata has high timber production potential under the current climatic and growth conditions in Latvia, and therefore this species has potential for use in forestry, as well as playing a significant role in maintaining biodiversity and other ecosystem services.

scholarly journals Oceanographic features and limited dispersal shape the population genetic structure of the vase sponge Ircinia campana in the Greater Caribbean

Heredity ◽  
2020 ◽  
Vol 126 (1) ◽  
pp. 63-76
Author(s):  
Sarah M. Griffiths ◽  
Mark J. Butler ◽  
Donald C. Behringer ◽  
Thierry Pérez ◽  
Richard F. Preziosi
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Population Genetic Structure ◽  
Larval Dispersal ◽  
Population Genetic ◽  
Spatial Genetic Structure ◽  
Florida Keys ◽  
The United States ◽  
Limited Dispersal ◽  
Mass Mortalities

AbstractUnderstanding population genetic structure can help us to infer dispersal patterns, predict population resilience and design effective management strategies. For sessile species with limited dispersal, this is especially pertinent because genetic diversity and connectivity are key aspects of their resilience to environmental stressors. Here, we describe the population structure of Ircinia campana, a common Caribbean sponge subject to mass mortalities and disease. Microsatellites were used to genotype 440 individuals from 19 sites throughout the Greater Caribbean. We found strong genetic structure across the region, and significant isolation by distance across the Lesser Antilles, highlighting the influence of limited larval dispersal. We also observed spatial genetic structure patterns congruent with oceanography. This includes evidence of connectivity between sponges in the Florida Keys and the southeast coast of the United States (>700 km away) where the oceanographic environment is dominated by the strong Florida Current. Conversely, the population in southern Belize was strongly differentiated from all other sites, consistent with the presence of dispersal-limiting oceanographic features, including the Gulf of Honduras gyre. At smaller spatial scales (<100 km), sites showed heterogeneous patterns of low-level but significant genetic differentiation (chaotic genetic patchiness), indicative of temporal variability in recruitment or local selective pressures. Genetic diversity was similar across sites, but there was evidence of a genetic bottleneck at one site in Florida where past mass mortalities have occurred. These findings underscore the relationship between regional oceanography and weak larval dispersal in explaining population genetic patterns, and could inform conservation management of the species.

The genetic diversity and spatial genetic structure of the Corso-Sardinian endemicFerula arrigoniiBocchieri (Apiaceae)

Plant Biology ◽  
2014 ◽  
Vol 16 (5) ◽  
pp. 1005-1013 ◽  
Author(s):  
C. A. Dettori ◽  
S. Sergi ◽  
E. Tamburini ◽  
G. Bacchetta
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Spatial Genetic Structure
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