scholarly journals GENETIC DIVERSITY AND DIFFERENTIATION OF Pseudotsuga menziesii (Mirb.) Franco POPULATIONS IN MÉXICO

2011 ◽  
Vol 34 (4) ◽  
pp. 233 ◽  
Author(s):  
Jorge Cruz-Nicolás ◽  
J. Jesús Vargas-Hernández ◽  
Porfirio Ramírez-Vallejo ◽  
Javier López-Upton
Keyword(s):  
Genetic Diversity ◽  
Pseudotsuga Menziesii ◽  
In Situ Conservation ◽  
Mantel Test ◽  
Douglas Fir ◽  
Population Divergence ◽  
Central Mexico ◽  
Gene Pools ◽  
Polymorphic Loci ◽  
Northwestern Mexico

Mexican populations of Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] constitute valuable gene pools for conservation and breeding programs of this species. Genetic diversity and population divergence were estimated using 18 isozyme loci and samples from 11 natural Douglas-fir populations in México. Genetic diversity was high at the species level (83.3 % polymorphic loci and 2.9 alleles per locus), but low at the population level (28.3 % polymorphic loci and 1.52 alleles per locus), particularly for populations from central México. A high level of population differentiation was found (Fst = 0.298), indicating that each population shares only a small fraction of the genetic diversity within the species and that genetic drift might have an important role in shaping the structure of genetic diversity in these populations. Genetic distances among populations in the Sierra Madre Oriental were positively correlated with geographic distances (r = 0.849), but the association was not significant according to the Mantel test. Populations from northeastern México separated from all others, whereas population Mohinora from northwestern México, joined those from central México. These results emphasize the priority for in situ conservation of Douglas-fir populations in central México.

scholarly journals Genetic diversity and population structure of Vernonia [Vernonia galamensis (Cass.) Less] populations from Ethiopia revealed by SSR markers

2019 ◽  
Author(s):  
Alemneh Mideksa Egu ◽  
Kifle Dagne ◽  
Kassahun Tesfaye ◽  
Xuebo Hu
Keyword(s):  
Genetic Diversity ◽  
Ssr Markers ◽  
Polymorphic Information Content ◽  
Major Gene ◽  
In Situ Conservation ◽  
Germplasm Conservation ◽  
Pharmaceutical Products ◽  
Gene Pools ◽  
Vernonia Galamensis ◽  
Diversity Assessment

Abstract BackgroundVernonia (Vernonia galamensis) is a potential novel industrial crop due to high demand for its natural epoxidised oil, which can be used for the manufacturing of oleochemicals such as paints, plastic formulations (polyvinyl chloride), and pharmaceutical products. This study is initiated for the systematic and intensive genetic diversity assessment of V. galamensis accessions by SSR molecular markers to minimize the existing research gaps, provide a clue for germplasm conservation and further research. ResultsTwenty SSR markers were used for genetic diversity analyses of 150 individual V. galamensis accessions representing 10 populations, from which a total of 79 bands were identified across the entire loci. All the loci used showed high polymorphism that ranged from 0.50 to 0.96, while the mean observed heterozygosity (Ho) was 0.15 across all the 20 markers evaluated. The molecular variance analysis (AMOVA) showed significant variations despite low differentiation among populations which accounted for only 11% of the total variations. Populations clustering showed that the dendrogram and principal coordinate’s analysis roughly classified the 150 accessions into four groups. However, the Bayesian model-based clustering (STRUCTURE) grouped into 6 (K = 6) major gene pools. These analyses showed accessions collected from the same region of origin did not often grouped entirely together within a given major groups. ConclusionsThe result suggested that the markers applied to ten populations, in which East Showa and East Harerghe revealed higher genetic diversity, signaled that these areas are the hotspots for in-situ conservation of V. galamensis. In addition, the values of SSR markers such as heterozygosity, Shannon‘s index, polymorphic information content, and population clusters are important baseline information for future V. galamensis cultivation, breeding and genetic resource conservation endeavors in Ethiopia.

scholarly journals Genetic diversity of seeds from four German Douglas fir (Pseudotsuga menziesii) seed orchards

2021 ◽  
Author(s):  
Birte Pakull ◽  
Pascal Eusemann ◽  
Janine Wojacki ◽  
Diana Ahnert ◽  
Heike Liesebach
Keyword(s):  
Genetic Diversity ◽  
Pseudotsuga Menziesii ◽  
Seed Orchard ◽  
Small Population ◽  
Douglas Fir ◽  
Next Generation ◽  
Seed Orchards ◽  
Population Sizes ◽  
Spatial Isolation ◽  
Offspring Generation

AbstractIn Germany, Douglas fir (Pseudotsuga menziesii Franco) is seen as a valuable species for future cultivation in times of climate change. Local seed production in seed stands and seed orchards may secure that local adaptation is transferred to the next generation, but small population sizes could lower genetic diversity and thus future adaptability. Here we analyse the transfer of genetic diversity from parent to offspring generation in four older German seed orchards. We detected low pollen contamination rates due to high levels of spatial isolation. Even with a relatively low number of 40 clones, seed orchard design with randomized and repeated planting of clones led to low selfing rates, and despite uneven parental contributions, the number of successful parents and the level of genetic intermixture were high enough to allow the transfer of an adequate part of the genetic diversity to the next generation. Larger numbers, however, might be needed to reliably conserve the entire genetic diversity over succeeding generations. Conclusions on the establishment of future seed orchards and regarding areas requiring further research are drawn at the end of the paper.

Genetic diversity in seeds produced in artificial Douglas-fir (Pseudotsuga menziesii) stands of different size

2019 ◽  
Vol 438 ◽  
pp. 18-24 ◽  
Author(s):  
Janine Wojacki ◽  
Pascal Eusemann ◽  
Diana Ahnert ◽  
Birte Pakull ◽  
Heike Liesebach
Keyword(s):  
Genetic Diversity ◽  
Pseudotsuga Menziesii ◽  
Douglas Fir

scholarly journals Low Divergence Among Natural Populations of Cornus kousa subsp. chinensis Revealed by ISSR Markers

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1082 ◽  
Author(s):  
Jia-Qiu Yuan ◽  
Qin Fang ◽  
Guo-Hua Liu ◽  
Xiang-Xiang Fu
Keyword(s):  
Genetic Diversity ◽  
Diversity Index ◽  
In Situ Conservation ◽  
Geographic Distance ◽  
Natural Populations ◽  
Issr Markers ◽  
Mantel Test ◽  
Distribution Area ◽  
Genetic Characteristics ◽  
Cornus Kousa

Research Highlights: Taking Chinese dogwood (Cornus kousa subsp. chinensis) as an example, the genetic characteristics of natural populations collected from main a distribution area were evaluated using intersimple sequence repeat (ISSR) markers to reveal the genetic basis for further selection and breeding. Background and Objectives: Chinese dogwood is a small understory tree that is widely distributed in China. Chinese dogwood has attracted interest for its potential horticultural and ornamental values, and its natural resource potential urgently needs to be estimated. Materials and Methods: In this study, the genetic diversity of 12 natural populations collected from six provinces containing 223 individuals was evaluated based on ISSR markers. Results: Relatively high levels of genetic diversity were found at both the population and individual levels. The Shannon’s diversity index (I) among individuals (0.504) was higher than that among populations (0.338). Analysis of molecular variance (AMOVA) revealed that genetic variation mainly existed within populations (61.55%) rather than among populations (38.45%). According to the STRUCTURE analysis, 12 populations were assigned to two groups, i.e., the northern and southern ecological regions, which are separated by the Yangtze River. A Mantel test analysis showed that there was no significant correlation between genetic distance and geographic distance. Conclusions: Considering the breeding system of dogwoods, we speculated that the genetic characteristics of the natural populations of this species would be affected by the dispersal mode of its pollens and seeds; additionally, genetic drift could play an important role in its genetic differentiation. In conclusion, in situ conservation is recommended for Chinese dogwood based on our results.

scholarly journals Phenotypic, Genetic, and Epigenetic Variation among Diverse Sweet Cherry Gene Pools

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 680
Author(s):  
Evangelia V. Avramidou ◽  
Theodoros Moysiadis ◽  
Ioannis Ganopoulos ◽  
Michail Michailidis ◽  
Christos Kissoudis ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Sweet Cherry ◽  
Allelic Variation ◽  
Sugar Content ◽  
Fruit Size ◽  
Mantel Test ◽  
Phenotypic Traits ◽  
Gene Pools ◽  
Epigenetic Diversity ◽  
Fruit Size And Shape

Sweet cherry germplasm contains a high variety of phenotypes which are associated with fruit size and shape as well as sugar content, etc. High phenotypic variation can be a result of genetic or epigenetic diversity that may interact through time. Recent studies have provided evidence that besides allelic variation, epiallelic variation can establish new heritable phenotypes. Herein we conducted a genetic and an epigenetic study (using amplified fragment length polymorphism (AFLP) and methylation-sensitive amplified polymorphism (MSAP) markers, respectively), accompanied by phenotypic traits correlation analysis in sweet cherry gene pools. The mean genetic diversity was greater than the epigenetic diversity (hgen = 0.193; hepi = 0.185), while no significant relationship was found between genetic and epigenetic distance according to a Mantel test. Furthermore, according to correlation analyses our results provided evidence that epigenetic diversity in predefined populations of sweet cherry had a stronger impact on phenotypic traits than their rich genetic diversity.

scholarly journals Genetic Diversity and Population Structure of Chinese Corylus heterophylla and Corylus kweichowensis Using Simple Sequence Repeat Markers

2020 ◽  
Vol 145 (5) ◽  
pp. 289-298
Author(s):  
Tiantian Zhao ◽  
Wenxu Ma ◽  
Qinghua Ma ◽  
Zhen Yang ◽  
Lisong Liang ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Relationships ◽  
In Situ Conservation ◽  
Geographic Distance ◽  
Natural Populations ◽  
Distinct Species ◽  
Mantel Test ◽  
Conservation Of Genetic Resources ◽  
Genetic Clusters

Corylus heterophylla and Corylus kweichowensis are economically and ecologically important nut-producing woody shrubs that are distributed across northern and southern regions of China. However, few studies have examined the genetic diversity and genetic relationships between C. heterophylla and C. kweichowensis, and their taxonomic relationships have been questioned. In this study, 796 individuals collected from 34 natural populations (21 C. heterophylla and 13 C. kweichowensis populations) were investigated to assess the genetic diversity and population structure using 11 microsatellite loci. Analysis of molecular variance revealed that genetic differentiation of C. heterophylla and C. kweichowensis within populations accounted for 93.57% and 88.91% of total variation, respectively. The C. heterophylla and C. kweichowensis populations as a whole group were analyzed by multiple programs, which showed that the 34 populations were divided into two genetic clusters. One cluster included 21 C. heterophylla populations, and the second cluster contained 13 C. kweichowensis populations. We conclude from these results that C. heterophylla and C. kweichowensis are distinct species. The Mantel test showed that the genetic distance was significantly correlated with the geographic distance (r = 0.580, P < 0.001). The populations of C. heterophylla [e.g., populations WC (Weichang), MS (Mishan), and WA (Wu’an)] and C. kweichowensis [e.g., populations YX (Yuexi), ZP (Zhenping), LA (Lin’an), and TB (Taibai)] with high allelic richness are considered suitable for in situ conservation. Our study provides valuable information for breeding and conservation of genetic resources of C. heterophylla, C. kweichowensis, and related species.

scholarly journals Variation in Microsatellite Loci Reveals a Natural Boundary of Genetic Differentiation among Pyrus betulaefolia Populations in Northern China

2017 ◽  
Vol 142 (5) ◽  
pp. 319-329 ◽  
Author(s):  
Yu Zong ◽  
Ping Sun ◽  
Xiaoyan Yue ◽  
Qingfeng Niu ◽  
Yuanwen Teng
Keyword(s):  
Genetic Diversity ◽  
In Situ Conservation ◽  
Northern China ◽  
Distinct Pattern ◽  
Habitat Destruction ◽  
Conservation Strategy ◽  
Ex Situ ◽  
Gene Pools ◽  
Natural Boundary ◽  
Microsatellite Variation

Pyrus betulaefolia is one of the most popular pear (Pyrus) rootstocks in China and other east Asian countries because of its good adaptability to versatile environments. However, the number of wild P. betulaefolia populations is decreasing because of habitat destruction and fragmentation. An urgent evaluation of P. betulaefolia genetic diversity and population structure is necessary to develop a conservation strategy for this important wild species. Thirteen simple sequence repeat loci were detected to infer the genetic composition of 18 P. betulaefolia populations in northern China. The average number of different alleles for each locus was 7.1. The number of effective alleles among loci ranged from 1.77 to 5.94. The overall mean values of expected and observed heterozygosity were 0.702 and 0.687, respectively. The Taihang Mountains, which run from northeast to southwest, acted as natural boundary in shaping the genetic diversity of P. betulaefolia in northern China. The distinct pattern, which was also observed in the distribution of chloroplast DNA (cpDNA) variation, appeared to be obscured by pollen-mediated gene flow in the distribution of nuclear microsatellite variation. Large populations with high allelic richness (e.g., populations BT, ZN, and QS) are considered suitable for in situ conservation because of the potential for adaptation to future environmental change. The smaller populations had mixed gene pools (e.g., populations GQ and XF) and should therefore also be considered for ex situ conservation. Preserving genetic diversity in seeds was proposed when field collections are fully characterized.

Natürliche und künstliche Verjüngung der Douglasie in Bayern aus genetischer Sicht

2012 ◽  
Vol 163 (3) ◽  
pp. 79-87 ◽  
Author(s):  
Monika Konnert ◽  
Barbara Fussi
Keyword(s):  
Genetic Diversity ◽  
Pseudotsuga Menziesii ◽  
Natural Regeneration ◽  
Coastal Region ◽  
Douglas Fir ◽  
Absolute Minimum ◽  
Seed Collection ◽  
Low Genetic Diversity ◽  
Provenance Trials ◽  
Adult Trees

Genetic aspects related to natural and artificial regeneration of Douglas-fir in Bavaria One of the most important factors when planting Douglas-fir is choosing the most suitable provenance for the site. Under climate change, genetic diversity as the basis for adaptation is of increasing importance. Both aspects, provenance and genetic diversity, have to be considered if natural regeneration of adult stands or planting of new stands are discussed. Numerous provenance trials have proven that the most suitable provenances for Bavaria originate from the coastal region west of the Cascade Mountains in Washington (Pseudotsuga menziesii var. menziesii). The interior variety (Pseudotsuga menziesii var. glauca and P. menziesii var. caesia) is unsuitable both because of growth rate and susceptibility to needle cast. However, not only coastal Douglas-fir was planted in Bavaria. Isozyme analysis showed that around 20% of the Bavarian stands represented interior Douglas-fir or a mixture of coastal and interior variety. Through natural regeneration the genetic structure of the adult trees is passed on to the following generation. If gene flow through pollen or seed from neighbouring stands occurs, significant changes in the genetic composition of natural regeneration in comparison with the adult generation will be observed. The same is true for the seed collected from adult stands. This must be taken into consideration when stands are selected as registered seed collection stands. Stands with low genetic diversity and mixture of green and gray variety of Douglas-fir have to be excluded from seed collection. To maintain an appropriate level of genetic diversity in the seed, cones should be collected from at least 20 trees per stand. This should be considered the absolute minimum. Concerning the level of genetic diversity in seed collections from Germany, West Washington (USA) and France (seed orchards), no clear differences were observed.

LINKAGE RELATIONSHIPS AMONG 19 POLYMORPHIC ALLOZYME LOCI IN COASTAL DOUGLAS-FIR (PSEUDOTSUGA MENZIESII var. MENZIESII)

1982 ◽  
Vol 24 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Y. A. El-Kassaby ◽  
O. Sziklai ◽  
F. C. Yeh
Keyword(s):  
Pseudotsuga Menziesii ◽  
Genetic Linkage ◽  
Douglas Fir ◽  
Conifer Species ◽  
Polymorphic Loci ◽  
Allozyme Loci ◽  
Linkage Relationships

Linkage relationships among 19 different polymorphic loci in coastal Douglas-fir (Pseudotsuga menziesii var. menziesii [Mirb.] Franco) were studied. A total of 115 of 171 possible two-locus combinations were tested. Out of the 115 combinations, a total of 106 conform to the hypothesis of independence between loci indicating that no linkage exists between these pairs. Of the remaining nine pairs, two were tightly linked with recombination frequencies of 0.02 (Aat2:Pgi2) and 0.22 (Aat3:Sod). The remaining were loosely linked, with recombination frequencies varying between 0.33 and 0.42. Two of these nine linked pairs have been detected in other conifer species. It was not possible to study three-point linkages due to the lack of appropriate combinations. To our knowledge, these results provide the first demonstration of genetic linkage in Douglas-fir.

scholarly journals Genetic diversity and population structure of Vernonia [Vernonia galamensis (Cass.) Less] populations from Ethiopia revealed by SSR markers

2020 ◽  
Author(s):  
Alemneh Mideksa Egu ◽  
Kassahun Tesfaye ◽  
Kifle Dagne New ◽  
Xuebo Hu New
Keyword(s):  
Genetic Diversity ◽  
Molecular Markers ◽  
Ssr Markers ◽  
Polymorphic Information Content ◽  
In Situ Conservation ◽  
Germplasm Conservation ◽  
Pharmaceutical Products ◽  
Gene Pools ◽  
Vernonia Galamensis ◽  
Diversity Assessment

Abstract Background: Vernonia (Vernonia galamensis) is a potential novel industrial crop due to high demand for its natural epoxidized oil, which can be used for the manufacturing of oleochemicals such as paints, plastic formulations (polyvinyl chloride), and pharmaceutical products. This study was initiated for the systematic and intensive genetic diversity assessment of V. galamensis accessions by SSR molecular markers to minimize the existing research gaps, provide a clue for germplasm conservation and further research. Results: Twenty SSR markers were used for genetic diversity analyses of 150 individual V. galamensis accessions representing 10 populations, from which a total of 79 bands were identified for the 20 loci. All the loci used showed high polymorphism that ranged from 0.50 to 0.96, while the mean observed heterozygosity (Ho) was 0.15 across all the 20 markers evaluated. The molecular variance analysis (AMOVA) showed significant variations among populations which accounted for 11% of the variations. Populations clustering showed that the dendrogram and principal coordinate’s analysis roughly classified the accessions into four groups. However, the Bayesian model-based clustering (STRUCTURE) grouped into 6 (K = 6) major gene pools. Since, the cluster and the STRUCTURE analyses did not group the populations into sharply distinct clusters, due to presence of gene flow and mode of reproduction of the plant. Conclusions: The SSR molecular markers used in this study are highly polymorphic. Among the ten populations, East Showa and East Hararghe revealed higher genetic diversity, signaled that these areas are the hotspots for in-situ conservation of V. galamensis. In addition, the values of SSR markers such as heterozygosity, Shannon‘s index, polymorphic information content, and population clusters are important baseline information for future V. galamensis cultivation, breeding and genetic resource conservation endeavors in Ethiopia.

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