scholarly journals Estimating Long-Term Mating Systems Using DNA Sequences

Genetics ◽  
1996 ◽  
Vol 142 (2) ◽  
pp. 619-627 ◽  
Author(s):  
Brook G Milligan
Keyword(s):  
Mating System ◽  
Population Size ◽  
Inbreeding Depression ◽  
Dna Sequences ◽  
Mating Systems ◽  
Natural Populations ◽  
Self Fertilization ◽  
Plant Mating Systems ◽  
The Relationship

Abstract Plant mating systems often involve a mixture of self fertilizations and outcross fertilizations. The degree of selfing has a large impact on the genetic composition of natural populations and on the evolution of the mating system itself in response to such factors as inbreeding depression. This paper describes a means of estimating the long-term rate of self-fertilization from samples of alleles taken from individuals in a population. Use is made of the genealogy of pairs of alleles at a locus within individuals and pairs between individuals. The degree of selfing is closely related to the extent to which the number of nucleotide sites differing within an individual is reduced relative to the number differing between individuals. Importantly, the estimate of long-term selfing is largely independent of population size and is not affected by historical fluctuations in population size; instead it responds directly to the mating system itself. The approach outlined here is most appropriate to evolutionary problems in which the long-term nature of the mating system is of interest, such as to determine the relationship between prior inbreeding and inbreeding depression.

Update on the Boundaries of the Curly Birch Range

2020 ◽  
pp. 9-21
Author(s):  
L.V. Vetchinnikova ◽  
◽  
A.F. Titov ◽  
◽  
Keyword(s):  
Population Size ◽  
Natural Populations ◽  
Forest Tree ◽  
Published Data ◽  
Population Approach ◽  
Key Factors ◽  
History Of ◽  
Individual Trees ◽  
Karelian Birch

The article reports on the application of the best known principles for mapping natural populations of curly (Karelian) birch Betula pendula Roth var. carelica (Mercklin) Hämet-Ahti – one of the most appealing representatives of the forest tree flora. Relying on the synthesis and analysis of the published data amassed over nearly 100 years and the data from own full-scale studies done in the past few decades almost throughout the area where curly birch has grown naturally, it is concluded that its range outlined in the middle of the 20th century and since then hardly revised is outdated. The key factors and reasons necessitating its revision are specified. Herewith it is suggested that the range is delineated using the population approach, and the key element will be the critical population size below which the population is no longer viable in the long term. This approach implies that the boundaries of the taxon range depend on the boundaries of local populations (rather than the locations of individual trees or small clumps of trees), the size of which should not be lower than the critical value, which is supposed to be around 100–500 trees for curly birch. A schematic map of the curly birch range delineated using this approach is provided. We specially address the problem of determining the minimum population size to secure genetic diversity maintenance. The advantages of the population approach to delineating the distribution range of curly birch with regard to its biological features are highlighted. The authors argue that it enables a more accurate delineation of the range; shows the natural evolutionary history of the taxon (although it is not yet officially recognized as a species) and its range; can be relatively easily updated (e.g. depending on the scope of reintroduction); should be taken into account when working on the strategy of conservation and other actions designed to maintain and regenerate this unique representative of the forest tree flora.

Plant mating systems and assessing population persistence in fragmented landscapes

2007 ◽  
Vol 55 (3) ◽  
pp. 239 ◽  
Author(s):  
David J. Coates ◽  
Jane F. Sampson ◽  
Colin J. Yates
Keyword(s):  
Mating System ◽  
Population Size ◽  
Mating Systems ◽  
Habitat Disturbance ◽  
Population Persistence ◽  
Population Variation ◽  
Conservation Strategies ◽  
Valuable Insight ◽  
Mixed Mating ◽  
Fragmented Landscapes

Population size and habitat disturbance are key factors likely to shape the mating system of populations in disturbed and fragmented landscapes. They would be expected to influence the availability and behaviour of the pollinator, the ability to find mates in self-incompatible species, inbreeding in self-compatible species and the size of the pollen pool. These in turn might be expected to influence key variables critical for population persistence such as seed production, seed germination and seedling fitness. Here we investigate mating-system variation in six rare species, i.e. Banksia cuneata, B. oligantha, Lambertia orbifolia (Proteaceae), Verticordia fimbrilepis subsp. fimbrilepis, Eucalyptus rameliana (Myrtaceae), Acacia sciophanes (Mimosaceae), and two common species, i.e. Calothamnus quadrifidus (Myrtaceae) and Acacia anfractuosa. All seven species are animal-pollinated relatively long-lived woody shrubs with mixed-mating systems. Population variation in mating-system parameters was investigated in relation to population size and habitat disturbance. We show that although the mating system will vary depending on pollination biology and life-history, as populations get smaller and habitat disturbance increases there is a trend towards increased inbreeding, smaller effective sizes of paternal pollen pools and greater variation in outcrossing among plants. From the species investigated in this study we have found that changes in the mating system can be useful indicators of population processes and can give valuable insight into the development of conservation strategies for the persistence of plant species following anthropogenic disturbance and landscape fragmentation.

scholarly journals Sexual reproduction with variable mating systems can resist asexuality in a rock–paper–scissors dynamics

2015 ◽  
Vol 2 (7) ◽  
pp. 140383 ◽  
Author(s):  
Juan Carranza ◽  
Vicente Polo
Keyword(s):  
Mating System ◽  
Sexual Reproduction ◽  
Parameter Space ◽  
Mating Systems ◽  
Reproductive Mode ◽  
Long Term Effects ◽  
Diploid Population ◽  
Theoretical Question ◽  
Equal Contribution

While sex can be advantageous for a lineage in the long term, we still lack an explanation for its maintenance with the twofold cost per generation. Here we model an infinite diploid population where two autosomal loci determine, respectively, the reproductive mode, sexual versus asexual and the mating system, polygynous (costly sex) versus monogamous (assuming equal contribution of parents to offspring, i.e. non-costly sex). We show that alleles for costly sex can spread when non-costly sexual modes buffer the interaction between asexual and costly sexual strategies, even without twofold benefit of recombination with respect to asexuality. The three interacting strategies have intransitive fitness relationships leading to a rock–paper–scissors dynamics, so that alleles for costly sex cannot be eliminated by asexuals in most situations throughout the parameter space. Our results indicate that sexual lineages with variable mating systems can resist the invasion of asexuals and allow for long-term effects to accumulate, thus providing a solution to the persisting theoretical question of why sex was not displaced by asexuality along evolution.

scholarly journals Improvement of Seed Orchard Management Based on Mating System of Cajuputi Trees

2015 ◽  
Vol 18 (1) ◽  
pp. 26 ◽  
Author(s):  
Noor Khomsah Kartikawati ◽  
Mohammad Naiem ◽  
Eko Bhakti Hardiyanto ◽  
Anto Rimbawanto
Keyword(s):  
Mating System ◽  
Mating Systems ◽  
Nuclear Dna ◽  
Environmental Changes ◽  
Seed Orchard ◽  
Genetic Potential ◽  
Genetically Improved ◽  
Viable Population ◽  
Key Words Mating System

Breeding plan of cajuputi in Indonesia is aimed to increase plantation productivity of oil yield and 1.8 cineole content. Seed orchard of cajuputi at Paliyan, Gunungkidul, established using selected and genetically improved materials, has been producing seeds for operational plantation. This seed orchard would perform optimally if the mating systems of all individuals contribute to the inheritance of all genetic potential of the offsprings. Therefore, investigation of the mating systems of cajuputi was indispensible. The study has been carried out on 10 selected mother trees and the 24 offsprings of each mother trees using 8 microsatellite markers of nuclear DNA, namely Hin-2 (100-132 bp), Hin-4 (79-114 bp), Hin-5 (128-148 bp), Hin-7 (136-224 bp), Sal-1 (93-99 bp), Sal-3 (118-219 bp), Xho-1 (96-111 bp) and Xho-4 (150-216 bp), respectively. The result showed relatively high genetic variation of the offspring (HE=0.602, HO=0.594) originated from parent trees in the seed orchard. Parent trees tend to outcross(tm=0.951, ts=0.806), although seeds originated from biparental inbred (tm – ts = 0.145) and correlated paternity(rp=0.098) have also been observed. This genetically viable population could maintain its reproduction fi tness forshort term and adapt to the dynamic environmental changes for long term. Key words: mating system, cajuputi, seed orchard, microsatellite

scholarly journals Life cycle expression of inbreeding depression in Eucalyptus regnans and inter-generational stability of its mixed mating system

2019 ◽  
Vol 124 (1) ◽  
pp. 179-187 ◽  
Author(s):  
A Rod Griffin ◽  
Brad M Potts ◽  
René E Vaillancourt ◽  
J Charles Bell
Keyword(s):  
Life Cycle ◽  
Mating System ◽  
Inbreeding Depression ◽  
Field Experiments ◽  
Natural Populations ◽  
Forest Tree ◽  
Mixed Mating ◽  
Mature Trees ◽  
Mixed Mating System ◽  
Eucalyptus Regnans

Abstract Background and Aims Many plants exhibit a mixed mating system. Published models suggest that this might be an evolutionarily stable rather than a transitional state despite the presence of inbreeding depression, but there is little empirical evidence. Through field experimentation, we studied the role of inbreeding depression in eliminating inbred progeny from the reproductive cohort of the forest tree Eucalyptus regnans, and demonstrate a stable mixed primary mating system over two successive generations. Methods Two field experiments were conducted using seed from natural populations. We sowed open-pollinated seeds to simulate a natural regeneration event and determined isozyme genotypes of dominant and suppressed individuals over 10 years. We also planted a mixture of open-pollinated, outcross and selfed families with common maternal parentage; monitored survival of cross types over 29 years; and determined the percentage of outcrosses in open-pollinated seed from a sample of reproductively mature trees using microsatellite analysis. Key Results Both experiments demonstrated progressive competitive elimination of inbred plants. By 29 years, the reproductive cohort in the planted experiment consisted only of outcrosses which produced seed which averaged 66 % outcrosses, similar to the estimate for the parental natural population (74 %). Conclusions Selective elimination of inbred genotypes during the intense intra-specific competition characteristic of the pre-reproductive phase of the life cycle of E. regnans results in a fully outcrossed reproductive population, in which self-fertility is comparable with that of its parental generation. The mixed mating system may be viewed as an unavoidable consequence of the species’ reproductive ecology, which includes the demonstrated effects of inbreeding depression, rather than a strategy which is actively favoured by natural selection.

The significance of sexual dimorphism in the mating system of two species of tephritid flies (Aciurina trixa and Valentibulla dodsoni) (Diptera: Tephritidae)

1987 ◽  
Vol 65 (1) ◽  
pp. 194-198 ◽  
Author(s):  
Gary Dodson
Keyword(s):  
Sexual Dimorphism ◽  
Mating System ◽  
Mating Systems ◽  
Natural Populations ◽  
Adaptive Significance ◽  
Male Behavior ◽  
Field Cage ◽  
Copulatory Success

The mating systems of Aciurina trixa and Valentibulla dodsoni (Diptera: Tephritidae) were observed in natural populations and field cage studies. Measurements of field-collected individuals of both species revealed that females were larger than males based on five size categories, but males had larger forefemora. Male behavior suggested that selection might favor increased foreleg size, due to a resulting enhancement of male ability to seize females prior to mounting. Male forefemur size was found to be a predictor of copulatory success in both species. Hypotheses concerning the adaptive significance of this sexual dimorphism are discussed.

scholarly journals Ant guards influence the mating system of their plant hosts by altering pollinator behaviour

2020 ◽  
Author(s):  
Nora Villamil ◽  
Karina Boege ◽  
Graham N. Stone
Keyword(s):  
Mating System ◽  
Community Composition ◽  
Mating Systems ◽  
Field Experiments ◽  
Plant Fitness ◽  
Pollinator Behaviour ◽  
Visitation Frequency ◽  
Pollinator Community ◽  
Plant Mating Systems ◽  
Plant Mating

AbstractAnt guards can increase plant fitness by deterring herbivores but may also reduce it by interfering with pollination, hence ant-plant interactions are ideal systems in which to study costs and benefits of mutualisms. While ant impacts on herbivory are well-studied, much less is known about impacts on pollinators and associated consequences for plant mating systems and fitness. We used field experiments to quantify the effect of ant guards on pollinator community composition, frequency and duration of flower visits, and cascading effects on plant mating system and plant fitness in Turnera velutina (Passifloraceae). Although ant patrolling did not affect pollinator community composition or visitation frequency, it decreased pollinator foraging time and flower visit duration. Such behavioural changes resulted in reduced pollen deposition on stigmas, decreasing male fitness whilst increasing outcrossing rates. This study contributes to understanding how non-pollinators, such as these defensive mutualists, can shape plant mating systems.

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