scholarly journals Phenotypic variation, functional traits repeatability and core collection inference in Synsepalum dulcificum (Schumach & Thonn.) Daniell reveals the Dahomey Gap as a centre of diversity

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Dèdéou A. Tchokponhoué ◽  
Enoch G. Achigan-Dako ◽  
Sognigbé N’Danikou ◽  
Daniel Nyadanu ◽  
Rémi Kahane ◽  
...  
Keyword(s):  
Functional Traits ◽  
Phenotypic Variation ◽  
Genetic Improvement ◽  
Core Collection ◽  
Ex Situ ◽  
Basic Knowledge ◽  
Fruit Traits ◽  
Centre Of Diversity ◽  
Fruit Mass ◽  
Tree Traits

Abstract The miracle plant Synsepalum dulcificum is a multipurpose natural sweetener and a promising West African orphan fruit shrub candidate for genetic improvement. Unfortunately, basic knowledge such as phenotypic variation and inheritance estimates required for implementing a breeding program are still lacking. A set of 203 accessions were sampled in two habitats from seven populations spread across the Dahomey Gap (DG) and the Upper Guinea forest (UG) in West Africa. The phenotypic diversity and allometric relationships among functional traits were analysed; the broad-sense heritability was estimated for fruit-traits, and a mini-core collection was developed in the species. Quantitative variation in tree- and fruit-traits was recorded, and multivariate analyses were performed to assess relationships among accessions, whereas heritability was estimated using the coefficient of repeatability. Tree-traits observed in S. dulcificum were more variable than fruit-traits. While habitat-type only affected tree-traits, the provenance population significantly affected both fruit- and tree-traits, with the UG populations outperforming the DG ones. Significant correlations were observed among fruit-traits on one hand, and among tree-traits on the other hand, whereas poor correlations were observed between tree- and fruit-traits. The multivariate analysis grouped accessions in three clusters. Promising individuals for high fruit mass and pulp-dense genotypes’ selection were identified within clusters. Repeatability estimates for fruit-traits ranged from 0.015 (edible ratio) to 0.88 (fruit mass). The Core Hunter algorithm enabled the extraction of 41 individuals as robust representatives of the initial set of 203 accessions, and the mapping of this core collection suggested Dahomey Gap as a centre of diversity of the species. These original findings offer opportunities, not only for the genetic improvement of S. dulcificum, but also for targeted ex-situ conservation in the species.

scholarly journals Double Haploid Development and Assessment of Androgenic Competence of Balkan Pepper Core Collection in Bulgaria

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2414
Author(s):  
Stanislava Grozeva ◽  
Gancho Pasev ◽  
Vesela Radeva-Ivanova ◽  
Velichka Todorova ◽  
Valentina Ivanova ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Double Haploid ◽  
Genetic Improvement ◽  
Core Collection ◽  
Culture Medium ◽  
Doubled Haploids ◽  
Caps Marker ◽  
Regenerated Plants ◽  
Direct Embryogenesis ◽  
Pepper Breeding

This study was designed to assess the androgenic potential of 180 pepper accessions and 11 progenies (four F1 and seven BC) possessing PMMoV resistance in order to complement an ongoing pepper breeding program. The experiment was carried out in 10 replications with 20 anthers for each accession in two different induction mediums from 2017 to 2019. The highest androgenic response was observed in culture medium 17-2 but differences between two mediums were nonsignificant. From a total of 191 genotypes, 102 genotypes expressed a potential for direct embryogenesis. Embryo induction was seen to be genotype-dependent and decreased in the following order: Pumpkin > Conical > Bell or blocky > Round > Elongate as the most responsive genotypes with over 10% reacted anthers being observed in CAPS-23, CAPS-29, CAPS-127, CAPS-157, CAPS-169, F1 and BC 887 derived from CAPS-23. The number of regenerated plants was higher in the conical group and least in the round varietal group. Regenerated plants were examined visually and by flow cytometry for identification of spontaneous doubled haploids (DH) and haploids. Those originating from F1 and BC progenies were additionally evaluated by a CAPS marker targeting L4 allele for resistance against PMMoV. Obtained results revealed two groups consisting of homozygous susceptible and resistant plants. Therefore, use of anther culture in ongoing breeding will greatly facilitate the pepper genetic improvement.

scholarly journals Seed Functional Traits Provide Support for Ecological Restoration and ex situ Conservation in the Threatened Amazon Ironstone Outcrop Flora

2020 ◽  
Vol 11 ◽  
Author(s):  
Marcilio Zanetti ◽  
Roberta L. C. Dayrell ◽  
Mariana V. Wardil ◽  
Alexandre Damasceno ◽  
Tais Fernandes ◽  
...  
Keyword(s):  
High Temperatures ◽  
Functional Traits ◽  
Niche Breadth ◽  
Seed Storage ◽  
Interspecific Variation ◽  
Ex Situ ◽  
Seed Traits ◽  
Physical Dormancy ◽  
Apparent Lack ◽  
Germination Traits

Cangas (ironstone outcrops) host a specialized flora, characterized by high degree of edaphic endemism and an apparent lack of natural history knowledge of its flora. Due to intense pressure from iron ore mining this ecosystem is under threat and in need of restoration. We studied seed functional traits that are relevant for restoration, translocation and ex situ conservation in 48 species from cangas in eastern Amazon. Were determined the thermal niche breadth, classified seed dormancy and determined methods to overcome it, determined the effect of seed storage on germination, tested the association between germination traits and functional groups, and tested whether seed traits are phylogenetically conserved. We found a broad interspecific variation in most seed traits, except for seed water content. Large interspecific variation in the temperature niche breadth was found among the studied species, but only four species, showed optimum germination at high temperatures of 35–40°C, despite high temperatures under natural conditions. Only 35% of the studied species produced dormant seeds. Mechanical scarification was effective in overcoming physical dormancy and application of gibberellic acid was effective in overcoming physiological dormancy in five species. For the 29 species that seeds were stored for 24 months, 76% showed decreases in the germination percentage. The weak association between germination traits and life-history traits indicate that no particular plant functional type requires specific methods for seed-based translocations. Exceptions were the lianas which showed relatively larger seeds compared to the other growth-forms. Dormancy was the only trait strongly related to phylogeny, suggesting that phylogenetic relatedness may not be a good predictor of regeneration from seeds in cangas. Our study provides support to better manage seed sourcing, use, storage and enhancement techniques with expected reduced costs and increased seedling establishment success.

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 Phenotypic diversity and plasticity index of Eurycoma apiculata populations in Eastern Sumatra, Indonesia based on leaves morphology

2020 ◽  
Vol 21 (7) ◽  
Author(s):  
Zulfahmi Zulfahmi ◽  
Edi Purwanto ◽  
Parjanto ◽  
Ahmad Yunus
Keyword(s):  
Phenotypic Plasticity ◽  
Phenotypic Variation ◽  
Phenotypic Diversity ◽  
In Situ Conservation ◽  
Plasticity Index ◽  
Ex Situ ◽  
Phenotypic Traits ◽  
Phenotypic Differentiation ◽  
Riau Archipelago ◽  
Conservation Method

Abstract. Zulfahmi, Purwanto E, Parjanto, Yunus A. 2020. Phenotypic diversity and plasticity index of Eurycoma apiculata populations in Eastern Sumatra, Indonesia based on leaves morphology. Biodiversitas 21: 2923-2934. Eurycoma apiculata A.W. Benn. is a protected species in Indonesia, but diversity information of this species is limited. The objective of this study was to assess the phenotypic diversity, phenotypic plasticity index, and phenotypic differentiation among populations of E. apiculata in Eastern Sumatra, Indonesia based on leaves morphology. A total of 45 traits were measured on leaves from six populations studied. The result of this found that the phenotypic variation coefficient (CV) of the characters was ranged from 7.41% to 36.97%, revealed the abundant phenotypic variation in the species. The phenotypic CV values of the population varied from 13.95% to 24.10%. The CV values of all populations from the mainland Sumatra (17.75%) were lower than that from the Riau archipelago (23.61%), which revealed that phenotypic traits in mainland Sumatra were more stable compared to populations in the Riau archipelago. The population phenotypic plasticity index value of populations ranged from 0.41 to 0.51, and it was classified as a moderate level. The phenotypic differentiation coefficient among populations in this study was relatively low (VST = 21.06%), indicating a lower phenotypic variation among populations than within populations. The scatter plot of principal component analysis and UPGMA dendrogram divided the six populations studies into two groups. The findings of this study recommend that the in-situ conservation method is an effective protection strategy for E. apiculata while ex-situ conservation method can be implemented as a supplementary method.

Genetic Improvement of Volume and Wood Properties of Jack Pine: Selection Strategies

1990 ◽  
Vol 66 (3) ◽  
pp. 281-286 ◽  
Author(s):  
S. Magnussen ◽  
C. T. Keith
Keyword(s):  
Wood Density ◽  
Genetic Gain ◽  
Phenotypic Variation ◽  
Genetic Improvement ◽  
Growth Traits ◽  
Wood Quality ◽  
Jack Pine ◽  
Quality Factors ◽  
Stem Taper ◽  
Selection Strategies

Six selection strategies aimed at genetically improving volume production and wood quality factors such as density, heartwood content, and stem taper are compared in a 20-year-old jack pine progeny trial. Selection indices were computed under various assumptions about economic values of the traits under selection and with contraints on the magnitude and direction of expected genetic gain. Stem taper, wood density, and heartwood content were under strong genetic control; however, the low phenotypic variation of wood density limits its potential for genetic improvement. Heartwood content emerged as a trait amenable for rapid genetic improvement. Despite low heritabilities the prospect of improving size-related traits was promising due to substantial phenotypic variation. Economic weights were important for the selection outcome and good progress was reported in all traits when volume received the highest weight. It was feasible to limit genetic gain in individual traits to predetermined relative levels but the cost in terms of reduced gain in unrestricted traits was economically debilitating. Concerns about undesirable concomitant changes in wood density, heartwood, and stem taper when breeding is based solely on growth traits were not confirmed by our data.

Some recent issues on the conservation of crop genetic resources in developing countries

Genome ◽  
1999 ◽  
Vol 42 (4) ◽  
pp. 562-569 ◽  
Author(s):  
S Jana
Keyword(s):  
Genetic Diversity ◽  
Developing Countries ◽  
Plant Breeding ◽  
Genetic Resources ◽  
Core Collection ◽  
Ex Situ ◽  
Crop Genetic Resources ◽  
Core Collections ◽  
Global Food Security ◽  
Crop Genetic Diversity

Crop genetic resources (CGRs) are renewable resources. These resources are enriched rather than depleted by their use in research and plant breeding. Both at the time of Vavilov and, later, in the early 1970s, when concerted international efforts to collect and preserve CGRs started with the initiatives of the International Board for Plant Genetic Resources (IBPGR), CGRs were considered to be the common heritage of humankind. Now, they are widely accepted as "national heritage." Possible impacts of this nationalization on the utilization and enrichment of global crop genetic diversity and, consequently, on global food security are issues of great significance. At present, efficient management and adequate use of CGRs are more important concerns than their further exploration and collection. To increase the use of preserved CGRs in plant breeding, the formation of core collections, by selecting representative subsets from large ex situ collections of CGRs, was recommended in 1984. Since then, the core-collection strategy has been further justified as a practical approach to genetic resources management, as well as to their conservation. As a cost-saving germplasm-management strategy, the core-collection concept has considerable merit. However, the rapidly increasing popularity of core collections may undermine the genetic wealth stored in national gene banks of both developed and developing countries. Distinction is made between subsets of working collections and core collections. When a small number of CGRs is required for specific plant breeding purposes, a properly formed working collection is more useful than a representative collection. Despite the relative abundance of genetic diversity in crop plants in traditional agroecosystems, maintenance of these agroecosystems is not a realistic long-term alternative for preserving crop genetic diversity and ensuring global food security. What is needed in the "gene-rich" developing countries is the adoption of "biodiversity friendly" plant breeding and agricultural practices.Key words: crop genetic resources, core collection, germplasm conservation, in situ conservation, ex situ conservation, modern landraces.

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