scholarly journals Evolution of flowering time in a selfing annual plant: Roles of adaptation and genetic drift

2020 ◽  
Author(s):  
Laurène Gay ◽  
Julien Dhinaut ◽  
Margaux Jullien ◽  
Renaud Vitalis ◽  
Miguel Navascués ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Flowering Time ◽  
Genetic Drift ◽  
Environmental Changes ◽  
Effective Size ◽  
Phenotypic Traits ◽  
Annual Plant ◽  
Response To Selection ◽  
Genetic Composition ◽  
Selection Gradient

Resurrection studies are a useful tool to measure how phenotypic traits have changed in populations and they allow testing whether these traits modifications are a response to selection caused by an environmental change. Selfing, through its reduction of effective size, could challenge the ability of a population to adapt to environmental changes. Here, we used a resurrection study to test for adaptation in a selfing population of Medicago truncatula, by comparing the genetic composition and flowering across 22 generations. We found evidence for evolution towards earlier flowering times by about two days and a peculiar genetic structure, typical for highly selfing population, where some multilocus genotypes (MLGs) are persistent through time. We used the change in frequency of the MLGs through time as a multilocus fitness measure and built a selection gradient that suggests evolution towards earlier flowering times. Yet, a simulation model revealed that the observed change in flowering time could be explained by drift alone, provided the effective size of the population is small enough (<150). These analyses suffer from the difficulty to estimate the effective size in a highly selfing population, where effective recombination is severely reduced.

Weedy Rice Diversity in Southern Brazil

Weed Science ◽  
2021 ◽  
pp. 1-37
Author(s):  
Leonard Bonilla Piveta ◽  
José Alberto Noldin ◽  
Nilda Roma-Burgos ◽  
Vívian Ebeling Viana ◽  
Lariza Benedetti ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Flowering Time ◽  
Weed Management ◽  
Phenotypic Diversity ◽  
Weedy Rice ◽  
Phenotypic Traits ◽  
Southern Brazil ◽  
Variable Response ◽  
Cultivated Rice ◽  
Flowering Synchrony

Abstract Weedy rice (Oryza sativa L.) is one of the most troublesome weeds affecting rice (Oryza sativa L.) production in many countries. Weedy rice control is difficult in rice fields because the weed and crop are phenotypically and morphologically similar. Weedy rice can be a source of genetic diversity to cultivated rice. Thus, this study aimed to characterize the morphological diversity of weedy rice in Southern Brazil. Qualitative and quantitative traits of 249 accessions from eight rice growing mesoregions in Rio Grande do Sul (RS) and Santa Catarina (SC) states were analyzed. For each accession, 24 morphological descriptors (14 qualitative and 10 quantitative) were evaluated. All the 249 accessions from RS and SC are of indica lineage. Considering all the phenotypic traits evaluated, the accessions separated into 14 distinct groups. One of the largest groups consisted of plants that were predominantly tall and with green leaves, intermediate shattering, and variable in flowering time. Distinct subgroups exist within larger clusters, showing discernable phenotypic diversity within the main clusters. The variability in flowering time was high (77 to 110 d after emergence), indicating high potential for flowering synchrony with rice cultivars and, consequently, gene flow. This indicates the need to remove escapes when planting herbicide-resistant rice. Thus, weedy rice populations in Southern Brazil are highly diverse and this diversity could result in variable response to weed management.

scholarly journals Conservation genetics of the threatened plant species Physaria filiformis (Missouri bladderpod) reveals strong genetic structure and a possible cryptic species

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247586
Author(s):  
Christine E. Edwards ◽  
Brooke C. Tessier ◽  
Joel F. Swift ◽  
Burgund Bassüner ◽  
Alexander G. Linan ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Genetic Structure ◽  
Plant Species ◽  
Genetic Drift ◽  
Rare Species ◽  
Ex Situ ◽  
Ouachita Mountains ◽  
Genetic Diversity And Structure ◽  
Genetic Clusters

Understanding genetic diversity and structure in a rare species is critical for prioritizing both in situ and ex situ conservation efforts. One such rare species is Physaria filiformis (Brassicaceae), a threatened, winter annual plant species. The species has a naturally fragmented distribution, occupying three different soil types spread across four disjunct geographical locations in Missouri and Arkansas. The goals of this study were to understand: (1) whether factors associated with fragmentation and small population size (i.e., inbreeding, genetic drift or genetic bottlenecks) have reduced levels of genetic diversity, (2) how genetic variation is structured and which factors have influenced genetic structure, and (3) how much extant genetic variation of P. filiformis is currently publicly protected and the implications for the development of conservation strategies to protect its genetic diversity. Using 16 microsatellite markers, we genotyped individuals from 20 populations of P. filiformis from across its geographical range and one population of Physaria gracilis for comparison and analyzed genetic diversity and structure. Populations of P. filiformis showed comparable levels of genetic diversity to its congener, except a single population in northwest Arkansas showed evidence of a genetic bottleneck and two populations in the Ouachita Mountains of Arkansas showed lower genetic variation, consistent with genetic drift. Populations showed isolation by distance, indicating that migration is geographically limited, and analyses of genetic structure grouped individuals into seven geographically structured genetic clusters, with geographic location/spatial separation showing a strong influence on genetic structure. At least one population is protected for all genetic clusters except one in north-central Arkansas, which should therefore be prioritized for protection. Populations in the Ouachita Mountains were genetically divergent from the rest of P. filiformis; future morphological analyses are needed to identify whether it merits recognition as a new, extremely rare species.

The Social and Genetic Structure of a Natural Colony of House Mice, Mus musculus, at Healesville WildlifeSanctuary

1983 ◽  
Vol 31 (2) ◽  
pp. 155 ◽  
Author(s):  
GR Singleton
Keyword(s):  
Genetic Structure ◽  
Life Span ◽  
Social Organization ◽  
Turnover Rate ◽  
Spatial Organization ◽  
House Mice ◽  
Genetic Composition ◽  
Short Life ◽  
Short Life Span ◽  
The Social

A 2-year program monitored the spatial organization, genetic structure and turnover rate of an unconfined commensal colony of mice. Four demes (social breeding units) were identified; each usually consisted of one or two males and two or three females. Demes were detected simultaneously in adjoining cages of an aviary (one deme per cage). Movement between demes was rare and the life span of a deme ranged from 2 to 7 months. The adult members of each deme had genotypes compatible to the majority of the young captured in the respective cage of the aviary at the time of residence of the deme. Taken in isolation, these results suggest that social behaviour would have a major impact on the genetic structure of the aviary population. When viewed over the main breeding season, the short life span of a deme and the genetic differences between demes indicate that social organization probably had only a temporary effect on the genetic composition of the aviary population.

scholarly journals Harvest-induced evolution: insights from aquatic and terrestrial systems

2017 ◽  
Vol 372 (1712) ◽  
pp. 20160036 ◽  
Author(s):  
Anna Kuparinen ◽  
Marco Festa-Bianchet
Keyword(s):  
Environmental Changes ◽  
Current Knowledge ◽  
Aquatic Systems ◽  
Phenotypic Traits ◽  
Size At Maturity ◽  
Phenotypic Changes ◽  
Harvest Intensity ◽  
Evolutionary Changes ◽  
Key Points ◽  
Ecological Implications

Commercial and recreational harvests create selection pressures for fitness-related phenotypic traits that are partly under genetic control. Consequently, harvesting can drive evolution in targeted traits. However, the quantification of harvest-induced evolutionary life history and phenotypic changes is challenging, because both density-dependent feedback and environmental changes may also affect these changes through phenotypic plasticity. Here, we synthesize current knowledge and uncertainties on six key points: (i) whether or not harvest-induced evolution is happening, (ii) whether or not it is beneficial, (iii) how it shapes biological systems, (iv) how it could be avoided, (v) its importance relative to other drivers of phenotypic changes, and (vi) whether or not it should be explicitly accounted for in management. We do this by reviewing findings from aquatic systems exposed to fishing and terrestrial systems targeted by hunting. Evidence from aquatic systems emphasizes evolutionary effects on age and size at maturity, while in terrestrial systems changes are seen in weapon size and date of parturition. We suggest that while harvest-induced evolution is likely to occur and negatively affect populations, the rate of evolutionary changes and their ecological implications can be managed efficiently by simply reducing harvest intensity. This article is part of the themed issue ‘Human influences on evolution, and the ecological and societal consequences'.

Response to Selection and Genetic Drift in Three Populations Derived from the Golden Glow Maize Population

Crop Science ◽  
2004 ◽  
Vol 44 (5) ◽  
pp. 1527-1534 ◽  
Author(s):  
David V. Butruille ◽  
Heyder D. Silva ◽  
Shawn M. Kaeppler ◽  
James G. Coors
Keyword(s):  
Genetic Drift ◽  
Response To Selection ◽  
Maize Population

scholarly journals The spread of genes in random mating control populations

1962 ◽  
Vol 3 (1) ◽  
pp. 1-10 ◽  
Author(s):  
J. W. James
Keyword(s):  
Genetic Drift ◽  
Gene Frequency ◽  
Random Mating ◽  
Effective Size ◽  
Relative Importance ◽  
Genetic Sampling ◽  
Under Sampling ◽  
Poultry Flock ◽  
The University

1. The effect of genetic sampling, when this sampling is without replacement, on variation in gene frequency is studied, and equations describing the genetic drift are derived. The effective size turns out to be about one greater than under sampling with replacement.2. The relation between ‘spread of genes’ and genetic drift is worked out.3. The University of Queensland control poultry flock is analysed by these methods.4. The design of control populations is discussed with particular reference to the relative importance of genetic drift and phenotypic sampling.

scholarly journals Dearth of polymorphism associated with a sustained response to selection for flowering time in maize

2015 ◽  
Vol 15 (1) ◽  
Author(s):  
Eleonore Durand ◽  
Maud I Tenaillon ◽  
Xavier Raffoux ◽  
Stéphanie Thépot ◽  
Matthieu Falque ◽  
...  
Keyword(s):  
Flowering Time ◽  
Sustained Response ◽  
Response To Selection ◽  
Selection For

scholarly journals Pollinator experience, neophobia and the evolution of flowering time

2008 ◽  
Vol 276 (1658) ◽  
pp. 935-943 ◽  
Author(s):  
Jessica Forrest ◽  
James D Thomson
Keyword(s):  
Frequency Dependence ◽  
Flowering Time ◽  
Environmental Changes ◽  
Flowering Phenology ◽  
Plant Population ◽  
Early Flowering ◽  
Reproductive Phenology ◽  
Pollinator Visitation ◽  
Pollinator Behaviour ◽  
Bee Foraging

Environmental changes, such as current climate warming, can exert directional selection on reproductive phenology. In plants, evolution of earlier flowering requires that the individuals bearing genes for early flowering successfully reproduce; for non-selfing, zoophilous species, this means that early flowering individuals must be visited by pollinators. In a laboratory experiment with artificial flowers, we presented captive bumble-bees ( Bombus impatiens ) with flower arrays representing stages in the phenological progression of a two-species plant community: Bees that had been foraging on flowers of one colour were confronted with increasing numbers of flowers of a second colour. Early flowering individuals of the second ‘species’ were significantly under-visited, because bees avoided unfamiliar flowers, particularly when these were rare. We incorporated these aspects of bee foraging behaviour (neophobia and positive frequency dependence) in a simulation model of flowering-time evolution for a plant population experiencing selection against late flowering. Unlike simple frequency dependence, a lag in pollinator visitation prevented the plant population from responding to selection and led to declines in population size. Pollinator behaviour thus has the potential to constrain evolutionary adjustments of flowering phenology.

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