Do island plant populations really have lower genetic variation than mainland populations? Effects of selection and distribution range on genetic diversity estimates

2015 ◽  
Vol 24 (4) ◽  
pp. 726-741 ◽  
Author(s):  
C. García-Verdugo ◽  
M. Sajeva ◽  
T. La Mantia ◽  
C. Harrouni ◽  
F. Msanda ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Distribution Range ◽  
Plant Populations ◽  
Diversity Estimates

scholarly journals Genetic variation and genetic structure within metapopulations of two closely related selfing and outcrossing Zingiber species (Zingiberaceae)

AoB Plants ◽  
2020 ◽  
Author(s):  
Rong Huang ◽  
Zong-Dian Zhang ◽  
Yu Wang ◽  
Ying-Qiang Wang
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Genetic Structure ◽  
Habitat Fragmentation ◽  
Spatial Genetic Structure ◽  
Full Range ◽  
Breeding Systems ◽  
Dispersal Ability ◽  
Phylogenetic Distance ◽  
Plant Populations

Abstract Habitat fragmentation strongly affects the genetic diversity of plant populations, and this has always attracted much research interest. Although numerous studies have investigated the effects of habitat fragmentation on the genetic diversity of plant populations, fewer studies have compared species with contrasting breeding systems while accounting for phylogenetic distance. Here, we compare the levels of genetic diversity and differentiation within and among subpopulations in metapopulations (at fine-scale level) of two closely related Zingiber species, selfing Zingiber corallinum and outcrossing Zingiber nudicarpum. Comparisons of the genetic structure of species from unrelated taxa may be confounded by the effects of correlated ecological traits or/and phylogeny. Thus, we possibly reveal the differences in genetic diversity and spatial distribution of genetic variation within metapopulations that relate to mating systems. Compared to outcrossing Z. nudicarpum, the subpopulation genetic diversity in selfing Z. corallinum was significantly lower, but the metapopulation genetic diversity was not different. Most genetic variation resided among subpopulations in selfing Z. corallinum metapopulations, while a significant portion of variation resided either within or among subpopulations in outcrossing Z. nudicarpum, depending on whether the degree of subpopulation isolation surpass the dispersal ability of pollen and seed. A stronger spatial genetic structure appeared within subpopulations of selfing Z. corallinum potentially due to restricted pollen flow and seed dispersal. In contrast, a weaker genetic structure was apparent in subpopulations of outcrossing Z. nudicarpum most likely caused by extensive pollen movement. Our study shows that high genetic variation can be maintained within metapopulations of selfing Zingiber species, due to increased genetic differentiation intensified primarily by the stochastic force of genetic drift among subpopulations. Therefore, maintenance of natural variability among subpopulations in fragmented areas is key to conserve the full range of genetic diversity of selfing Zingiber species. For outcrossing Zingiber species, maintenance of large populations is an important factor to enhance genetic diversity.

scholarly journals Isoenzymatic and cytological studies of some Asiatic species of the genus Salsola

2014 ◽  
Vol 71 (2) ◽  
pp. 115-120 ◽  
Author(s):  
Aleksandra Wojnicka-Półtorak ◽  
Ewa Chudzińska ◽  
Elena Shuiskay ◽  
Hanna Barczak ◽  
Kristina Toderich ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Chromosome Number ◽  
Directional Selection ◽  
Plant Populations ◽  
Isozyme Electrophoresis ◽  
Low Level ◽  
Enzyme Systems ◽  
Asiatic Species ◽  
Haematoxylin Staining

The genetic and cytological variability of population of three <em>Salsola</em> species from Asia was investigated, using isozyme electrophoresis and haematoxylin staining. Eight enzyme systems, representing 14-17 loci, were examined: 6PGD, DIA, G6PD, GDH, GOT, MDH, PGM and PGI. Analysis of the chromosome number revealed that the three species have the same number of chromosomes: <em>2n=18</em>. Parameters describing genetic diversity indicate a very low level of genetic variation of the studied populations. The isozyme data support hypothesis that strong directional selection can result in lower level of genetic variation of arid plant populations.

scholarly journals Potential effects of life history on demographic genetic structure in stage-structured plant populations

2021 ◽  
Author(s):  
Yoichi Tsuzuki ◽  
Takenori Takada ◽  
Masashi Ohara
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Life History ◽  
Genetic Structure ◽  
Temporal Dynamics ◽  
Structured Populations ◽  
Plant Populations ◽  
Expected Heterozygosity ◽  
Neutral Locus ◽  
Two Indices

Standing genetic variation, or genetic diversity, is a source of adaptive evolution, and is crucial for long-term population persistence under environmental changes. One empirical method to predict the temporal dynamics of standing genetic variation in age- or stage-structured populations is to compare genetic diversity and composition among age/stage classes. The resultant within-population genetic structure, sometimes referred to as demographic genetic structure, has been regarded as a proxy of potential genetic changes that accompany sequential generation turnover. However, especially in stage-structured plant populations, individuals in more juvenile stages do not necessarily represent future populations, as they might die, stop growing, or retrogress over the course of life history. How demographic genetic structure is subjected to life history and whether it is a good proxy of temporal genetic dynamics had remained unclear. Here, we developed a matrix model which well describes temporal dynamics of expected heterozygosity, a common proxy of genetic diversity, for a neutral locus in stage-structured populations under equilibrium assumption. Based on the model, two indices of demographic genetic structure were formulated: relative ratio of expected heterozygosity and genetic differentiation among stage classes. We found that the two indices were largely determined by stable stage distribution and population size, and that they did not show clear correlations with the change rate of genetic diversity, indicating that inferring future genetic diversity from demographic genetic structure conventionally is misleading. Our study facilitates reliable interpretation on empirical demographic genetic data.

Genetic Analysis of Chinese Cucumber Collections in the U.S. National Germplasm Collection

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 534e-534 ◽  
Author(s):  
J. Staub ◽  
Felix Sequen ◽  
Tom Horejsi ◽  
Jin Feng Chen
Keyword(s):  
Genetic Diversity ◽  
Principal Component Analysis ◽  
Genetic Variation ◽  
Genetic Analysis ◽  
Allelic Variation ◽  
Germplasm Collection ◽  
Principal Component ◽  
Isozyme Loci ◽  
National Plant Germplasm System ◽  
The U.S

Genetic variation in cucumber accessions from China was assessed by examining variation at 21 polymorphic isozyme loci. Principal component analysis of allelic variation allowed for the depiction of two distinct groupings of Chinese accessions collected in 1994 and 1996 (67 accessions). Six isozyme loci (Gpi, Gr, Mdh-2, Mpi-2, Pep-gl, and Pep-la) were important in elucidating these major groups. These groupings were different from a single grouping of Chinese 146 accessions acquired before 1994. Allelic variation in Chinese accessions allowed for comparisons with other accessions in the U.S. National Plant Germplasm System (U.S. NPGS) collection grouped by continent and sub-continent. When Chinese accessions taken collectively were compared with an array of 853 C. sativus U.S. NPGS accessions examined previously, relationships differed between accessions grouped by country or subcontinent. Data indicate that acquisition of additional Chinese and Indian cucumber accessions would be strategically important for increasing genetic diversity in the U.S. NPGS cucumber collection.

Genetic variation for micronutrients and study of genetic diversity in diverse germplasm of rice

2020 ◽  
Vol 16 (1) ◽  
pp. 101-109
Author(s):  
S.K. TRIPATHY
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation

scholarly journals Genetic Diversity of Landraces and Improved Varieties of Rice (Oryza sativa L.) in Taiwan

Rice ◽  
2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Ai-ling Hour ◽  
Wei-hsun Hsieh ◽  
Su-huang Chang ◽  
Yong-pei Wu ◽  
Han-shiuan Chin ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Indigenous Peoples ◽  
Oryza Sativa L ◽  
Crop Improvement ◽  
Genetic Erosion ◽  
Germplasm Conservation ◽  
Gene Pools ◽  
Improved Varieties ◽  
Breeding Goals

Abstract Background Rice, the most important crop in Asia, has been cultivated in Taiwan for more than 5000 years. The landraces preserved by indigenous peoples and brought by immigrants from China hundreds of years ago exhibit large variation in morphology, implying that they comprise rich genetic resources. Breeding goals according to the preferences of farmers, consumers and government policies also alter gene pools and genetic diversity of improved varieties. To unveil how genetic diversity is affected by natural, farmers’, and breeders’ selections is crucial for germplasm conservation and crop improvement. Results A diversity panel of 148 rice accessions, including 47 cultivars and 59 landraces from Taiwan and 42 accessions from other countries, were genotyped by using 75 molecular markers that revealed an average of 12.7 alleles per locus with mean polymorphism information content of 0.72. These accessions could be grouped into five subpopulations corresponding to wild rice, japonica landraces, indica landraces, indica cultivars, and japonica cultivars. The genetic diversity within subpopulations was: wild rices > landraces > cultivars; and indica rice > japonica rice. Despite having less variation among cultivars, japonica landraces had greater genetic variation than indica landraces because the majority of Taiwanese japonica landraces preserved by indigenous peoples were classified as tropical japonica. Two major clusters of indica landraces were formed by phylogenetic analysis, in accordance with immigration from two origins. Genetic erosion had occurred in later japonica varieties due to a narrow selection of germplasm being incorporated into breeding programs for premium grain quality. Genetic differentiation between early and late cultivars was significant in japonica (FST = 0.3751) but not in indica (FST = 0.0045), indicating effects of different breeding goals on modern germplasm. Indigenous landraces with unique intermediate and admixed genetic backgrounds were untapped, representing valuable resources for rice breeding. Conclusions The genetic diversity of improved rice varieties has been substantially shaped by breeding goals, leading to differentiation between indica and japonica cultivars. Taiwanese landraces with different origins possess various and unique genetic backgrounds. Taiwanese rice germplasm provides diverse genetic variation for association mapping to unveil useful genes and is a precious genetic reservoir for rice improvement.

scholarly journals Genetic melting pot and importance of long-distance dispersal indicated in the Gladiolus imbricatus L. populations in the Polish Carpathians

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Agnieszka Sutkowska ◽  
Józef Mitka ◽  
Tomasz Warzecha ◽  
Jakub Bunk ◽  
Julia Rutkowska ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Diversity Indices ◽  
Western Carpathians ◽  
Genetic Structuring ◽  
Long Distance ◽  
Plant Populations ◽  
Genetic Stock ◽  
Melting Pot ◽  
Mountain Ranges ◽  
Eastern Carpathians

AbstractThe genetic diversity in 11 populations of Gladiolus imbricatus in five mountain ranges, including the Tatra, Pieniny, Gorce, Beskid Niski (Western Carpathians) and Bieszczady Mts (Eastern Carpathians), was studied with inter-simple sequence repeat (ISSR) markers. The species is a perennial plant occurring in open and semi-open sites of anthropogenic origin (meadows and forest margins). We checked a hypothesis on the microrefugial character of the plant populations in the Pieniny Mts, a small calcareous Carpathian range of complicated relief that has never been glaciated. Plant populations in the Tatra and Pieniny Mts had the highest genetic diversity indices, pointing to their long-term persistence. The refugial vs. the non-refugial mountain ranges accounted for a relatively high value of total genetic variation [analysis of molecular variance (AMOVA), 14.12%, p = 0.003]. One of the Pieniny populations was of hybridogenous origin and shared genetic stock with the Tatra population, indicating there is a local genetic melting pot. A weak genetic structuring of populations among particular regions was found (AMOVA, 4.5%, p > 0.05). This could be an effect of the frequent short-distance and sporadic long-distance gene flow. The dispersal of diaspores between the remote populations in the Western Carpathians and Eastern Carpathians could be affected by the historical transportation of flocks of sheep from the Tatra to Bieszczady Mts.

scholarly journals Phylogeography of Prunus armeniaca L. revealed by chloroplast DNA and nuclear ribosomal sequences

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wen-Wen Li ◽  
Li-Qiang Liu ◽  
Qiu-Ping Zhang ◽  
Wei-Quan Zhou ◽  
Guo-Quan Fan ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Chloroplast Dna ◽  
Population Expansion ◽  
Prunus Armeniaca ◽  
River Valley ◽  
Nuclear Ribosomal Dna ◽  
Glacial Refugium ◽  
Ili River Valley ◽  
Wild Apricot

AbstractTo clarify the phytogeography of Prunus armeniaca L., two chloroplast DNA fragments (trnL-trnF and ycf1) and the nuclear ribosomal DNA internal transcribed spacer (ITS) were employed to assess genetic variation across 12 P. armeniaca populations. The results of cpDNA and ITS sequence data analysis showed a high the level of genetic diversity (cpDNA: HT = 0.499; ITS: HT = 0.876) and a low level of genetic differentiation (cpDNA: FST = 0.1628; ITS: FST = 0.0297) in P. armeniaca. Analysis of molecular variance (AMOVA) revealed that most of the genetic variation in P. armeniaca occurred among individuals within populations. The value of interpopulation differentiation (NST) was significantly higher than the number of substitution types (GST), indicating genealogical structure in P. armeniaca. P. armeniaca shared genotypes with related species and may be associated with them through continuous and extensive gene flow. The haplotypes/genotypes of cultivated apricot populations in Xinjiang, North China, and foreign apricot populations were mixed with large numbers of haplotypes/genotypes of wild apricot populations from the Ili River Valley. The wild apricot populations in the Ili River Valley contained the ancestral haplotypes/genotypes with the highest genetic diversity and were located in an area considered a potential glacial refugium for P. armeniaca. Since population expansion occurred 16.53 kyr ago, the area has provided a suitable climate for the population and protected the genetic diversity of P. armeniaca.

scholarly journals Genetic and Epigenetic Changes during the Upward Expansion of Deyeuxia angustifolia Kom. in the Alpine Tundra of the Changbai Mountains, China

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 291
Author(s):  
Biao Ni ◽  
Jian You ◽  
Jiangnan Li ◽  
Yingda Du ◽  
Wei Zhao ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Dna Methylation ◽  
Genetic Variation ◽  
Soil Properties ◽  
Changbai Mountains ◽  
Epigenetic Variation ◽  
Geographical Distance ◽  
Mantel Tests ◽  
Epigenetic Diversity ◽  
Different Populations

Ecological adaptation plays an important role in the process of plant expansion, and genetics and epigenetics are important in the process of plant adaptation. In this study, genetic and epigenetic analyses and soil properties were performed on D. angustifolia of 17 populations, which were selected in the tundra zone on the western slope of the Changbai Mountains. Our results showed that the levels of genetic and epigenetic diversity of D. angustifolia were relatively low, and the main variation occurred among different populations (amplified fragment length polymorphism (AFLP): 95%, methylation sensitive amplification polymorphism (MSAP): 87%). In addition, DNA methylation levels varied from 23.36% to 35.70%. Principal component analysis (PCA) results showed that soil properties of different populations were heterogeneous. Correlation analyses showed that soil moisture, pH and total nitrogen were significantly correlated with genetic diversity of D. angustifolia, and soil temperature and pH were closely related to epigenetic diversity. Simple Mantel tests and partial Mantel tests showed that genetic variation significantly correlated with habitat or geographical distance. However, the correlation between epigenetic variation and habitat or geographical distance was not significant. Our results showed that, in the case of low genetic variation and genetic diversity, epigenetic variation and DNA methylation may provide a basis for the adaptation of D. angustifolia.

scholarly journals Spatial pattern and genetic diversity estimates are linked in stochastic models of population differentiation

2000 ◽  
Vol 23 (3) ◽  
pp. 541-544 ◽  
Author(s):  
José Alexandre Felizola Diniz-Filho ◽  
Mariana Pires de Campos Telles
Keyword(s):  
Genetic Diversity ◽  
Spatial Pattern ◽  
Stochastic Models ◽  
Population Differentiation ◽  
Real Data ◽  
Population Heterogeneity ◽  
Data Set ◽  
Mantel’S Test ◽  
The Relationship ◽  
Diversity Estimates

In the present study, we used both simulations and real data set analyses to show that, under stochastic processes of population differentiation, the concepts of spatial heterogeneity and spatial pattern overlap. In these processes, the proportion of variation among and within a population (measured by G ST and 1 - G ST, respectively) is correlated with the slope and intercept of a Mantel's test relating genetic and geographic distances. Beyond the conceptual interest, the inspection of the relationship between population heterogeneity and spatial pattern can be used to test departures from stochasticity in the study of population differentiation.

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