Genetic diversity and mating system of an endangered tree Eucalyptus morrisbyi

2005 ◽  
Vol 53 (4) ◽  
pp. 367 ◽  
Author(s):  
R. C. Jones ◽  
G. E. McKinnon ◽  
B. M. Potts ◽  
R. E. Vaillancourt
Keyword(s):  
Genetic Diversity ◽  
Small Population ◽  
Ex Situ ◽  
Endangered Tree ◽  
High Genetic Diversity ◽  
Vegetative Regeneration ◽  
Adult Trees ◽  
Outcrossing Rates ◽  
Chloroplast Haplotypes ◽  
The 19Th Century

Eucalyptus morrisbyi is an endangered eucalypt, restricted to four populations on the island of Tasmania. The two main populations are separated by 20 km, occurring in the Risdon Hills and on Calverts Hill, and differ markedly in size and health. Although they are both in reserves, the small population at Risdon Hills has experienced a marked decline in the last two decades. The other two populations (Lumeah Point and Honeywood Drive) are very small and under threat because of urbanisation. They are close to the large Calverts Hill population and may be remnants of a once larger population in this area prior to clearing for agriculture in the 19th century. A hypervariable chloroplast marker and six nuclear microsatellites, used to quantify genetic diversity among and within populations, indicated marked genetic differences between the two main populations (Risdon and Calverts Hills), with virtually no sharing of chloroplast haplotypes and little sharing of microsatellite alleles among populations. Both of the main populations are clearly required to adequately conserve the genetic diversity in this species, whereas the Lumeah Point and Honeywood Drive populations are similar to the proximal Calverts Hill population. The two main populations showed equally high levels of genetic diversity (average HE = 0.69) in the adult trees, using microsatellites, and little difference in inbreeding levels despite the large difference in population size. Analyses of 366 offspring from 9–11 trees from each main population revealed high outcrossing rates, little bi-parental inbreeding and high genetic diversity (average HE = 0.65) in both seedling populations. This indicates that open-pollinated seed collections from these populations capture sufficient genetic diversity for ex situ conservation plantings. It is argued that the high genetic diversity maintained in the small Risdon Hills population is due to a combination of the longevity of its genotypes (possibly up to 1155–1523 years) through a well developed mechanism of vegetative regeneration from lignotubers, coupled with high outcrossing rates maintained by a strong self-incompatibility mechanism.

scholarly journals Schinus Terebinthifolia Raddi: A Comparative Framework On Population Genetic Structure In A Restored Area After 12 Years*

2021 ◽  
Author(s):  
Erica Moraes Santos de Souza ◽  
Sheila Valéria Álvares-Carvalho ◽  
Robério Anastácio Ferreira ◽  
Renata Silva Mann
Keyword(s):  
Genetic Diversity ◽  
Continuous Monitoring ◽  
Diversity Index ◽  
Limiting Factor ◽  
Effective Population ◽  
Natural Area ◽  
High Genetic Diversity ◽  
Seed Sources ◽  
Adult Trees ◽  
Ssr Primers

Abstract The success of restoration projects depends upon the genetic diversity of the implanted species. It is a limiting factor, often because the seed sources are immersed in highly fragmented landscapes. This work was carried out to compare the genetic diversities of the juveniles and the adult trees of Schinus terebinthifolia Raddi in a mixed reforestation area, both in the restoration process and in the remaining natural area in the Atlantic Forest. Through five SSR primers, it was observed that the implanted population showed a greater genetic diversity index (He) (0.553 adults and 0.505 juveniles) when compared to the wild population (0.487 adults and 0.483 juveniles). It indicated that the forested area was established with individuals of high genetic diversity. There was a reduction of genetic diversity, with the loss of exclusive alleles and maintenance of inbreeding and coancestry in the juveniles of the reforested population. It can be inferred that there was a low gene flow among the fragments. The effective population size in both populations (adults and juveniles) was lower than that recommended for conserving populations in the short and long terms. These results have shown that continuous monitoring of this particular area is of absolute necessity and for applying techniques that can promote the connectivity of the fragments. It would allow for a more significant reduction of genetic drift and the persistence of the planted populations.

scholarly journals High Genetic Diversity and Low Differentiation in Michelia shiluensis, an Endangered Magnolia Species in South China

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 469 ◽  
Author(s):  
Yanwen Deng ◽  
Tingting Liu ◽  
Yuqing Xie ◽  
Yaqing Wei ◽  
Zicai Xie ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variation ◽  
Human Disturbance ◽  
Haplotype Diversity ◽  
Conservation Strategy ◽  
Ex Situ ◽  
Conservation Strategies ◽  
High Genetic Diversity ◽  
Cpdna Markers

Research Highlights: This study is the first to examine the genetic diversity of Michelia shiluensis (Magnoliaceae). High genetic diversity and low differentiation were detected in this species. Based on these results, we discuss feasible protection measures to provide a basis for the conservation and utilization of M. shiluensis. Background and Objectives: Michelia shiluensis is distributed in Hainan and Guangdong province, China. Due to human disturbance, the population has decreased sharply, and there is thus an urgent need to evaluate genetic variation within this species in order to identify an optimal conservation strategy. Materials and Methods: In this study, we used eight nuclear single sequence repeat (nSSR) markers and two chloroplast DNA (cpDNA) markers to assess the genetic diversity, population structure, and dynamics of 78 samples collected from six populations. Results: The results showed that the average observed heterozygosity (Ho), expected heterozygosity (He), and percentage of polymorphic loci (PPL) from nSSR markers in each population of M. shiluensis were 0.686, 0.718, and 97.92%, respectively. For cpDNA markers, the overall haplotype diversity (Hd) was 0.674, and the nucleotide diversity was 0.220. Analysis of markers showed that the genetic variation between populations was much lower based on nSSR than on cpDNA (10.18% and 77.56%, respectively, based on an analysis of molecular variance (AMOVA)). Analysis of the population structure based on the two markers shows that one of the populations (DL) is very different from the other five. Conclusions: High genetic diversity and low population differentiation of M. shiluensis might be the result of rich ancestral genetic variation. The current decline in population may therefore be due to human disturbance rather than to inbreeding or genetic drift. Management and conservation strategies should focus on maintaining the genetic diversity in situ, and on the cultivation of seedlings ex-situ for transplanting back to their original habitat.

scholarly journals Beyond the Coral Triangle: high genetic diversity and near panmixia in Singapore's populations of the broadcast spawning sea star Protoreaster nodosus

2016 ◽  
Vol 3 (8) ◽  
pp. 160253 ◽  
Author(s):  
Y. C. Tay ◽  
M. W. P. Chng ◽  
W. W. G. Sew ◽  
F. E. Rheindt ◽  
K. P. P. Tun ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Marine Invertebrates ◽  
Small Population ◽  
Population Connectivity ◽  
Marine Biodiversity ◽  
Coral Triangle ◽  
Sea Star ◽  
High Genetic Diversity ◽  
Broadcast Spawning ◽  
Genome Wide

The Coral Triangle is widely considered the most important centre of marine biodiversity in Asia while areas on its periphery such as the South China Sea, have received much less interest. Here, we demonstrate that a small population of the knobbly sea star Protoreaster nodosus in Singapore has similarly high levels of genetic diversity as comparable Indonesian populations from the Coral Triangle. The high genetic diversity of this population is remarkable because it is maintained despite decades of continued anthropogenic disturbance. We postulate that it is probably due to broadcast spawning which is likely to maintain high levels of population connectivity. To test this, we analysed 6140 genome-wide single nucleotide polymorphism (SNP) loci for Singapore's populations and demonstrate a pattern of near panmixia. We here document a second case of high genetic diversity and low genetic structure for a broadcast spawner in Singapore, which suggests that such species have high resilience against anthropogenic disturbances. The study demonstrates the feasibility and power of using genome-wide SNPs for connectivity studies of marine invertebrates without a sequenced genome.

Genotyping of Albania olive (Olea europaea) germplasm by SSR molecular marker

2018 ◽  
pp. 573 ◽  
Author(s):  
Innocenzo Muzzalupo ◽  
Antonella Muto, Giuliana Badolati ◽  
Aulona Veizi ◽  
Adriana Chiappetta
Keyword(s):  
Genetic Diversity ◽  
Ex Situ ◽  
Clear Correlation ◽  
High Genetic Diversity ◽  
High Productivity ◽  
Plant Nursery ◽  
Olive Cultivars ◽  
Ex Situ Collections ◽  
Olive Varieties

The increasing interest in olive varieties with high productivity and quality is the basis of modern olive growing. The molecular characterization of olive varieties is essential to maximize the genetic diversity in the in situ and ex situ collections of the olive germplasm. The importance of studies aimed at identification and selection of genotypes that meet the requirements for plant nursery certification, for oils traceability and to preserve genotypes that are not widespread from risks of extinction, is evident. In this context, DNA fingerprinting represents a valid tool because the productivity and quality of olive oil are intrinsic characteristics of the original varieties. To date, the Albanian olive-growing heritage has been little studied and the number of varieties has not yet been well defined. As a consequence, it doesn’t a precise characterization of the Albanian genetic entities. The aim of this work was to contribute in clarifying the identity of the Albanian olive cultivars, using the SSR molecular markers. We have genotyped olive trees at the level of nine nuclear microsatellite loci or SSR, pre-selected among those present in the literature and we have identified 38 unique genotypes. It has not been possible to establish a clear correlation between clustering of plants, depending on molecular profiles, and the geographical distribution of origin or maturation period or the intended use of drupes. However, our results show a high genetic diversity and a high discrimination capacity of the tested SSR markers.  

High genetic diversity of in situ and ex situ populations of Madagascan coffee species: further implications for the management of coffee genetic resources

2013 ◽  
Vol 9 (5) ◽  
pp. 1295-1312 ◽  
Author(s):  
Domohina N. Andrianasolo ◽  
Aaron P. Davis ◽  
Norosoa J. Razafinarivo ◽  
Serge Hamon ◽  
Jean-Jacques Rakotomalala ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Resources ◽  
Ex Situ ◽  
High Genetic Diversity ◽  
Coffee Species

Genetic diversity of mocó cotton (Gossypium hirsutum race marie-galante) from the northeast of Brazil: implications for conservation

Botany ◽  
2010 ◽  
Vol 88 (8) ◽  
pp. 765-773 ◽  
Author(s):  
Ivandilson Pessoa Pinto de Menezes ◽  
Paulo Augusto Vianna Barroso ◽  
Lúcia Vieira Hoffmann ◽  
Valeska Silva Lucena ◽  
Marc Giband
Keyword(s):  
Genetic Diversity ◽  
Gossypium Hirsutum ◽  
Geographic Origin ◽  
Rio Grande ◽  
Ex Situ ◽  
High Genetic Diversity ◽  
Breeding Programs ◽  
Extinction Process ◽  
Total Genetic Diversity ◽  
High Level

Mocó cotton ( Gossypium hirsutum  L. race marie-galante (Watt) Hutch.) is a potential source of valuable alleles for breeding programs, mainly because of its great adaptability to semi-arid conditions. With the aim of quantifying mocó cotton genetic variability, 187 plants collected in the northeast of Brazil were evaluated using 12 microsatellite markers. A total of 62 alleles were amplified, ranging from three to eight polymorphic alleles per locus. Total genetic diversity was high (0.52), and when measured on a per state basis, was of 0.37 on average. The population showed a low level of heterozygozity (HO = 0.16), reflecting a high level of endogamy (FIS = 0.67). Phylogenetic analysis using the neighbor-joining method revealed that plants sampled in different states tended to cluster according to their geographic origin, except for those collected in the states of Paraíba and Rio Grande do Norte, which grouped together. Plants from the state of Piauí formed two groups, one with an apparent allelic contribution from G. barbadense, while the second group of plants was closer to those from the states of Paraíba and Rio Grande do Norte. Despite the high genetic diversity that was observed in the remaining populations, urgent conservation efforts should be undertaken, owing to the high level of endogamy and accelerated extinction process that characterizes these populations. Such efforts should focus on the collection and ex situ maintenance of representative genetic diversity.

scholarly journals STUDY OF GENETIC DIVERSITY AND ANALYSIS OF THE DEGREE OF SIMILARITY IN SOME APPLE AND PLUM VARIETIES USING RAPD MARKERS

2021 ◽  
Vol 37 (37) ◽  
pp. 19-26
Author(s):  
Adina Iancu ◽  
◽  
Mihai Chivu ◽  
Keyword(s):  
Genetic Diversity ◽  
Genetic Distance ◽  
Rapd Markers ◽  
The Other ◽  
Ex Situ ◽  
Allelic Polymorphism ◽  
High Genetic Diversity ◽  
Ex Situ Collection ◽  
Plum Varieties ◽  
Degree Of Similarity

Molecular evaluation of germplasm is an important step in breeding programs, and the application of molecular biological techniques has led to important results in terms of both within- and between-species variability of traits. The RAPD technique has been successfully used to reveal allelic polymorphism as well as to measure genetic similarity. In this study, the genetic diversity of 25 genotypes and cultivars for apple species and 26 genotypes and cultivars for plum species was assessed with six RAPD markers. All these cultivars belong to the ex situ collection of apple and the ex situ collection of plum at the Research Institute for Fruit Growing Pitesti. The average number of amplified bands was 19.2 for apple and 17.66 for plum. Statistical analysis of intraspecific allelic polymorphism was expressed using the PIC (Polymorphic Information Content) index, which takes into account the allelic frequency. Two statistical indices were used to quantify genetic diversity: the Shannon index and the Simpson index. The degree of similarity between varieties was analyzed using the NTSYSpc version 2.1. Following RAPD analyses, the allele sizes of the analyzed varieties were within the range quoted in the literature, the genetic profiles of the studied varieties suggesting a medium to high genetic diversity, except for markers OPBC-04 and OPBB-05 for plum species, which expressed a high genetic diversity. Genetic distances calculated based on polymorphism of migrated bands in agarose gel confirmed the known genealogies of the apple and plum varieties studied. Thus, the smallest genetic distance for apple species was found between 'Jonagold' and 'Golden Delicious', 'Pionier' and 'Rustic', 'Jonathan' and 'Idared', 'Wagener Premiat' and 'Granny Smith', 'Remar' and 'Aura', 'Romus 3' and 'Rome Beauty', and the largest between Malus floribunda and the other genotypes studied. In plum, the smallest genetic distance was found between 'Dani' and 'Tita', 'Roman' and 'Tuleu gras', 'Dara' and 'Haganta', 'Romanța' and 'Stanley', 'Anna Spath' and 'Renclod Violet', and the largest between 'Lama', 'Black Diamond' and the other genotypes studied.

scholarly journals Conservation biology of threatened Mediterranean chasmophytes: The case of Asperula naufraga endemic to Zakynthos island (Ionian islands, Greece)

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246706 ◽  
Author(s):  
Anna-Thalassini Valli ◽  
Vassiliki Lila Koumandou ◽  
Gregoris Iatrou ◽  
Marios Andreou ◽  
Vasileios Papasotiropoulos ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Size ◽  
Extinction Risk ◽  
Conservation Status ◽  
Small Population ◽  
Ex Situ ◽  
Current Conservation ◽  
Ionian Islands ◽  
Small Population Size ◽  
Area Of Occupancy

Asperula naufraga is a rare and threatened obligate chasmophyte, endemic to Zakynthos island (Ionian islands, Greece). In this study, we provide a combined approach (including monitoring of demographic and reproductive parameters and study of genetic diversity) to assess the current conservation status of the species and to estimate its future extinction risk. The five subpopulations of A. naufraga were monitored for five years (2014–2018). Population size markedly fluctuated between 68–130 mature individuals during the monitoring period. The extent of occurrence (EOO) was estimated at 28.7 km2 and the area of occupancy (AOO) was 8 km2. Stage-structure recordings were similar for all subpopulations, characterized by high proportions of adult and senescent individuals, following a common pattern, which has been observed in other cliff-dwelling plants. Preliminary genetic analysis with SSRs markers revealed low heterozygosity within subpopulations and significant departure from H-W equilibrium, which combined with small population size suggest increased threat of genetic diversity loss. Our results indicate that the species should be placed in the Critically Endangered (CR) IUCN threat category, while according to Population Viability Analysis results its extinction risk increases to 47.8% in the next 50 years. The small population size combined with large fluctuations in its size, low recruitment and low genetic diversity, indicate the need of undertaking effective in situ and ex situ conservation measures.

scholarly journals Genetic diversity and population structure of Amorphophallus albus, a plant species with extremely small populations (PSESP) endemic to dry-hot valley of Jinsha River

2020 ◽  
Author(s):  
Rong Tang ◽  
Erxi Liu ◽  
Yazhou Zhang ◽  
Johann Schinnerl ◽  
Weibang Sun ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variation ◽  
Plant Species ◽  
Ex Situ ◽  
Small Populations ◽  
Wild Populations ◽  
Jinsha River ◽  
High Genetic Diversity ◽  
Cultivated Populations

Abstract Background: Amorphophallus albus P. Y. Liu & J. F. Chen (Araceae) is a plant species with extremely small populations (PSESP) and an important economic crop endemic to dry-hot valleys along the Jinsha River. In order to gain information for sustaining the development and conservation of A. albus, we studied the genetic diversity and population structure of this species using microsatellite markers (SSR). In this study, we analysed 364 individuals belonging to 24 populations, including four wild populations and three ex-situ cultivated populations, collected in the provinces Yunnan, Sichuan and Hubei. Results: The population genetic analyses indicated that A. albus possesses moderate genetic diversity with the percentage of polymorphic loci (PPL) from 69.23% to 100%, an expected heterozygosity (He) of 0.504 and an average Shannon's Information Index (I) 0.912. Analysis of molecular variance (AMOVA) indicated that most of the variance (71%) resided within populations and the estimated gene flow (Nm) was 0.61. The results of UPGMA cluster tree, STRUCTURE analyses together with the Mantel test (R2 = 0.352, P < 0.01) indicated that geographically closely located populations are clustered together with some exceptions. Conclusions: Our results showed that A. albus still possesses moderate genetic variation in most of the studied populations, and for now, most cultivated populations were naturally distributed but still some reintroduction exists. For sustaining the present genetic variation, some protections measures are necessary for the wild populations and also for the cultivated ones with high genetic diversity.

Assessment of molecular diversity in landraces of bread wheat (Triticum aestivum L.) held in an ex situ collection with Diversity Arrays Technology (DArT™)

2007 ◽  
Vol 58 (12) ◽  
pp. 1174 ◽  
Author(s):  
B. J. Stodart ◽  
M. C. Mackay ◽  
H. Raman
Keyword(s):  
Genetic Diversity ◽  
Molecular Diversity ◽  
Polymorphic Information Content ◽  
Ex Situ ◽  
Dart Markers ◽  
Strong Positive Correlation ◽  
High Genetic Diversity ◽  
Diversity Arrays Technology ◽  
Wheat Landraces ◽  
Landrace Accessions

Diversity Arrays Technology (DArT™) was evaluated as a tool for determining molecular diversity of wheat landraces held within the Australian Winter Cereals Collection (AWCC). Initially, a set of 44 wheat landraces was evaluated with 256 DArT markers. The dataset was compared with the results obtained using 16 amplified fragment length polymorphism (AFLP) primer combinations and 63 simple sequence repeat (SSR) markers, mapped on the 21 chromosomes, from a previous study. The DArT markers exhibited a strong positive correlation with AFLP and SSR, with each marker type distinguishing similar relationships among the 44 landrace accessions. The DArT markers exhibited a higher polymorphic information content than AFLP, and were comparable with that obtained with SSR. Three hundred and fifty-five DArT markers were then used to evaluate genetic diversity among 705 wheat landrace accessions from within the AWCC, chosen to represent 5 world regions. DArT analysis was capable of distinguishing accessions from different geographic regions, and suggested that accessions originating from Nepal represent a unique gene pool within the collection. A statistical resampling of DArT loci indicated that 10–20 loci were enough to distinguish the maximum molecular diversity present within the collection. This research demonstrates the efficacy of the DArT platform as a tool for efficient examination of wheat diversity. As an ex situ germplasm repository, the AWCC contains wheat accessions of high genetic diversity, from genetically differentiated collection sites, even though diversity was under-represented in some countries represented in the repository.

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