Estimating genetic diversity, mating system and pollen dispersal to inform ex situ conservation of tree Genipa americana L.

2021 ◽  
pp. 1-11
Author(s):  
Marília Freitas de Vasconcelos Melo ◽  
Alexandre Magno Sebbenn ◽  
Bruno Cesar Rossini ◽  
Ana Veruska Cruz da Silva Muniz ◽  
Carlos Jose Rodrigues ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Mating System ◽  
Pollen Dispersal ◽  
Ex Situ ◽  
Fixation Index ◽  
Lower Probability ◽  
Dispersal Pattern ◽  
Long Distance ◽  
Dioecious Species ◽  
Seed Collection

Abstract Using microsatellite loci, we assessed the mating system and genetic diversity of the dioecious tropical tree Genipa americana in a natural population (NP) and a progeny test (PT). For NP, we also estimated the paternity correlation within and among fruits and mean pollen dispersal distance. As expected for dioecious species, all offspring originated from outcrossing (t = 1). Mating among relatives (1 − ts) and paternity correlation (rp) were variable among progenies (1 − ts = 0.03–0.19; rp = 0.04–0.40), but greater in NP than in PT. Fixation index (F) was generally significant and lower in adults than in offspring, indicating selection against inbred individuals. Paternity correlation was higher within (0.40) than among (0.26) fruits, indicating a lower effective number of pollen donors (Nep) within (2.5) than among (3.8) fruits. Due to the higher rp in NP, the effective size within progenies (Ne) was lower (2.69) than PT (3.27). The pollen dispersal pattern was strongly leptokurtic, suggesting long-distance pollen dispersal (mean of 179 m). The results show that both populations can be used for seed collection in environmental reforestation programmes; however, considering that PT is structured in maternal progenies, NP is more suitable for seed collection due to the lower probability of mating among related trees.

scholarly journals Evaluating restoration outcomes through assessment of pollen dispersal, mating system and genetic diversity

2020 ◽  
Author(s):  
Melissa A Millar ◽  
David J Coates ◽  
Margaret Byrne ◽  
Siegfried L Krauss ◽  
Justin Jonson ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Mating System ◽  
Pollen Dispersal

scholarly journals Assessment of genetic diversity and population structure of oil palm (Elaeis guineensis Jacq.) field genebank: A step towards molecular-assisted germplasm conservation

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0255418
Author(s):  
Siou Ting Gan ◽  
Chin Jit Teo ◽  
Shobana Manirasa ◽  
Wei Chee Wong ◽  
Choo Kien Wong
Keyword(s):  
Genetic Diversity ◽  
Genetic Distance ◽  
Oil Palm ◽  
Core Collection ◽  
Elaeis Guineensis ◽  
Germplasm Conservation ◽  
Ex Situ ◽  
Fixation Index ◽  
Core Set ◽  
Genetic Diversity And Structure

Oil palm (Elaeis guineensis) germplasm is exclusively maintained as ex situ living collections in the field for genetic conservation and evaluation. However, this is not for long term and the maintenance of field genebanks is expensive and challenging. Large area of land is required and the germplasms are exposed to extreme weather conditions and casualty from pests and diseases. By using 107 SSR markers, this study aimed to examine the genetic diversity and relatedness of 186 palms from a Nigerian-based oil palm germplasm and to identify core collection for conservation. On average, 8.67 alleles per SSR locus were scored with average effective number of alleles per population ranging from 1.96 to 3.34 and private alleles were detected in all populations. Mean expected heterozygosity was 0.576 ranging from 0.437 to 0.661 and the Wright’s fixation index calculated was -0.110. Overall moderate genetic differentiation among populations was detected (mean pairwise population FST = 0.120, gene flow Nm = 1.117 and Nei’s genetic distance = 0.466) and this was further confirmed by AMOVA analysis. UPGMA dendogram and Bayesian structure analysis concomitantly clustered the 12 populations into eight genetic groups. The best core collection assembled by Core Hunter ver. 3.2.1 consisted of 58 palms accounting for 31.2% of the original population, which was a smaller core set than using PowerCore 1.0. This core set attained perfect allelic coverage with good representation, high genetic distance between entries, and maintained genetic diversity and structure of the germplasm. This study reported the first molecular characterization and validation of core collections for oil palm field genebank. The established core collection via molecular approach, which captures maximum genetic diversity with minimum redundancy, would allow effective use of genetic resources for introgression and for sustainable oil palm germplasm conservation. The way forward to efficiently conserve the field genebanks into next generation without losing their diversity was further discussed.

scholarly journals Molecular genetic diversity and mating system in sacha inchi progenies1

2017 ◽  
Vol 47 (4) ◽  
pp. 480-487 ◽  
Author(s):  
Mágno Sávio Ferreira Valente ◽  
Maria Teresa Gomes Lopes ◽  
Francisco Célio Maia Chaves ◽  
Mozanil Correia Pantoja ◽  
Francy Mary Galúcio Sousa ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Mating System ◽  
Urban Communities ◽  
Molecular Genetic ◽  
Aflp Markers ◽  
Ex Situ ◽  
Breeding Programs ◽  
Molecular Genetic Diversity ◽  
Sacha Inchi ◽  
Allogamous Species

ABSTRACT Sacha inchi (Plukenetia volubilis L.) is a species with nutraceutical benefits traditionally consumed by Amazonic indigenous and urban communities. Studies on the genetic diversity and mating system are required to preserve and make the best use of the genetic resources for this species. This study aimed to estimate the genetic diversity and mating system parameters of sacha inchi progenies using Amplified Fragment Length Polymorphism (AFLP) markers. A total of 360 progenies from 30 accessions of sacha inchi were analyzed using three AFLP primers combinations. The percentage variation between and within families and the crossing rate, among other parameters, were estimated. The AFLP markers were efficient in genetically differentiating progenies, revealing 251 (98.82 %) polymorphic fragments. The analysis of molecular variance showed that the strongest variation occurs between progenies (57.16 %). However, the genetic differentiation within progenies was considerable (42.84 %), and could be exploited in breeding programs. The estimated population outcrossing rate was high (0.957), indicating it is a predominantly allogamous species. On the other hand, 33.7 % of the crosses occurred between related individuals. The estimate for biparental crosses revealed that the progenies consisted mainly of half-siblings (66.9 %) and full-siblings (28.8 %). For purposes of breeding and ex situ genetic conservation, sacha inchi seeds should be collected from a large number of parent plants.

scholarly journals Estimating coancestry within open-pollinated progenies of a dioecious species: the case study of Myracrodruon urundeuva

2012 ◽  
Vol 61 (1-6) ◽  
pp. 256-264 ◽  
Author(s):  
M. A. Moraes ◽  
A. P. S. Gaino ◽  
M. L. T. Moraes ◽  
M. L. M. Freitas ◽  
A. M. Sebbenn
Keyword(s):  
Tree Breeding ◽  
Accurate Method ◽  
Effective Size ◽  
Ex Situ ◽  
Data Sets ◽  
Dioecious Species ◽  
Coancestry Coefficient ◽  
Seed Collection ◽  
Area Of Interest ◽  
Mating Model

Abstract Understanding the coancestry coefficient within openpollinated progenies has long been an area of interest because of the implications of coancestry on estimates of additive genetic variation, variance effective size and the number of seed trees required for seed collection for ex situ conservation, tree breeding and environmental restoration. This study compares three methods to calculate the coancestry coefficient within open-pollinated progenies of the dioecious tree species, Myracrodruon urundeuva, using six microsatellite loci. The methods compared were: i) correlated mating model (CMM) (RITLAND, 1989); ii) TWOGENER method (SMOUSE et al., 2001) to estimate the differentiation among pollen pools (TGM); and iii) HARDY et al.’s 2004 method using the estimate of coancestry from LOISELLE et al. (1995) (HLM) and from RITLAND (1996) (HRM). The data analysis was based on four data sets: two populations were composed of 12 progenies, two of 24 progenies, and all progenies consisted of 15 plants. The coancestry estimated using CMM ranged among populations from 0.145 to 0.158, using TGM it ranged from 0.153 to 0.181, using HLM from 0.153 to 0.162, and HRM from 0.144 to 0.147. To investigate the bias of the estimates of true relatedness within progenies we simulated two half-sib and two full-sib populations. The most accurate method found in the study was CMM because the estimated values presented no bias for true half- or full-sib progenies and these values were very similar to those expected (0.125 and 0.25, respectively). These results have significant implications for breeding and conservation programs because coancestry-within-progenies is a key parameter in assessing the variance effective size.

scholarly journals Diversity and spatial genetic structure of a natural population of Theobroma speciosum (Malvaceae) in the Brazilian Amazon

2016 ◽  
Vol 64 (3) ◽  
Author(s):  
Juliana De Freitas Encinas Dardengo ◽  
Ana Aparecida Bandini Rossi ◽  
Bruna Mezzalira da Silva ◽  
Ivone Vieira da Silva ◽  
Carolina Joana da Silva ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Natural Population ◽  
Short Distance ◽  
Ex Situ Conservation ◽  
Spatial Genetic Structure ◽  
Near Neighbor ◽  
Ex Situ ◽  
Conservation Areas ◽  
Seed Collection

The quantification of genetic diversity and intrapopulation spatial genetic structure (SGS) of tree species are important aspects for in and ex situ conservation practices. In this study we seek to understand the importance of conservation areas by quantifying the genetic diversity and the spatial genetic structure of a natural population of Theobroma speciosum. Within this population, 49 adults and 51 subadults were genotyped for five microsatellite loci. The results showed that adults and subadults have similar levels of genetic diversity and inbreeding (adults: A= 10.4, Ae = 10.3, F= 0.68, subadults: A= 10.6, Ae= 10.6, F= 0.57). Genetic diversity was spatially structured within the population, and the results suggest that near-neighbor trees up to a distance of 70 m are likely related. SGS is likely the result of short-distance seed dispersal, the short-distance range of pollinators, and infrequent breaches of the self-incompatible mating system. Considering the high demographic density of the species and size of the study area, as well as the high average number of alleles per locus and the presence of rare alleles, we believe that the study population is an excellent resource for in situ genetic conservation of T. speciosum. The study area is also a useful resource for collecting germplasm for ex situ conservation and seed collection, either for breeding programs used in the restoration of degraded areas or forest improvement. 

scholarly journals Pollen dispersal, pollen immigration, mating and genetic diversity in restoration of the southern plains Banksia

2020 ◽  
Vol 129 (4) ◽  
pp. 773-792
Author(s):  
Melissa A Millar ◽  
David J Coates ◽  
Margaret Byrne ◽  
Siegfried L Krauss ◽  
Matthew R Williams ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Differentiation ◽  
Mating System ◽  
Mating Systems ◽  
Pollen Dispersal ◽  
Floral Display ◽  
Molecular Tools ◽  
Plant Populations ◽  
Southern Plains ◽  
Population Fitness

Abstract Evaluation of patterns of pollen dispersal, mating systems, population fitness, genetic diversity and differentiation in restoration and remnant plant populations can be useful in determining how well restoration activities have achieved their objectives. We used molecular tools to assess how well restoration objectives have been met for populations of Banksia media in the biodiversity hotspot of south-west Western Australia. We characterized patterns of pollen dispersal within, and pollen immigration into, two restoration populations. We compared mating system parameters, population fitness via seed weight, genetic diversity and genetic differentiation for restoration and associated reference remnant populations. Different patterns of pollen dispersal were revealed for two restoration sites that differed in floral display, spatial aggregation of founders and co-planted species. Proximity to remnant native vegetation was associated with enhanced immigration and more short-range pollen dispersal when other population variables were constant. Greater seed weights at remnant compared to restoration populations were not related to outcrossing rate. Equivalent mating system and genetic diversity parameters and low to moderate levels of genetic differentiation between restoration and remnant populations suggest pollinator services have been restored in genetically diverse restoration populations of local provenance B. media as early as four years from planting.

scholarly journals Patterns of Fine-Scale Spatial Genetic Structure and Pollen Dispersal in Giant Sequoia (Sequoiadendron giganteum)

Forests ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 61
Author(s):  
Rainbow DeSilva ◽  
Richard S. Dodd
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Spatial Genetic Structure ◽  
Spatial Scales ◽  
Pollen Dispersal ◽  
Detailed Examination ◽  
Background Information ◽  
Long Distance ◽  
Giant Sequoia ◽  
Sequoiadendron Giganteum

Research Highlights: Patterns of dispersal shape the distribution and temporal development of genetic diversity both within and among populations. In an era of unprecedented environmental change, the maintenance of extant genetic diversity is crucial to population persistence. Background and Objectives: We investigate patterns of pollen dispersal and spatial genetic structure within populations of giant sequoia (Sequoiadendron giganteum). Materials and Methods: The leaf genotypes of established trees from twelve populations were used to estimate the extent of spatial genetic structure within populations, as measured by the Sp statistic. We utilized progeny arrays from five populations to estimate mating parameters, the diversity of the pollen pool, and characteristics of pollen dispersal. Results: Our research indicates that giant sequoia is predominantly outcrossing, but exhibits moderate levels of bi-parental inbreeding (0.155). The diversity of the pollen pool is low, with an average of 7.5 pollen donors per mother tree. As revealed by the Sp-statistic, we find significant genetic structure in ten of twelve populations examined, which indicates the clustering of related individuals at fine spatial scales. Estimates of pollen and gene dispersal indicate predominantly local dispersal, with the majority of pollen dispersal <253 m, and with some populations showing fat-tailed dispersal curves, suggesting potential for long-distance dispersal. Conclusions: The research presented here represent the first detailed examination of the reproductive ecology of giant sequoia, which will provide necessary background information for the conservation of genetic resources in this species. We suggest that restoration planting can mitigate potential diversity loss from many giant sequoia populations.

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