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Premise: Variation in seed traits is common within and among populations of plant species and often has ecological and evolutionary implications. However, due to the time‐consuming nature of manual seed measurements and the level of variability in imaging techniques, quantifying and interpreting the extent of seed variation can be challenging. Methods: We developed a standardized high‐throughput technique to measure seed number, as well as individual seed area and color, using a derived empirical scale to constrain area in Arabidopsis thaliana, Brassica rapa, and Mimulus guttatus. We develop a specific rational model using seed area measured at various spatial scales relative to the pixel count, observing the asymptotic value of the seed area as the modeled number of pixels approaches infinity. Results: We found that our model has high reliability in estimating seed traits and efficiently processes large numbers of images, facilitating the quantification of seed traits in studies with large sample sizes. Discussion: This technique facilitates consistency between imaging sessions and standardizes the measurement of seed traits. These novel advances allow researchers to directly and reliably measure seed traits, which will enable tests of the ecological and evolutionary causes of their variation. [ABSTRACT FROM AUTHOR]

Reproductive timing is a key life‐history trait that impacts the pool of available mates, the environment experienced during flowering, and the expression of other traits through genetic covariation. Selection on phenology, and its consequences on other life‐history traits, has considerable implications in the context of ongoing climate change and shifting growing seasons. To test this, we grew field‐collected seed from the wildflower Mimulus guttatus in a greenhouse to assess the standing genetic variation for flowering time and covariation with other traits. We then created full‐sib families through phenological assortative mating and grew offspring in three photoperiod treatments representing seasonal variation in daylength. We find substantial quantitative genetic variation for the onset of flowering time, which covaried with vegetative traits. The assortatively‐mated offspring varied in their critical photoperiod by over two hours, so that families differed in their probability of flowering across treatments Allocation to flowering and vegetative growth changed across the daylength treatments, with consistent direction and magnitude of covariation among flowering time and other traits. Our results suggest that future studies of flowering time evolution should consider the joint evolution of correlated traits and shifting seasonal selection to understand how environmental variation influences life histories. Reproductive timing is a key life‐history trait that affects the pool of available mates, the environment experienced during flowering, and the expression of other traits through genetic covariation. We found a broad distribution of heritable variation in flowering time and correlated traits, providing the potential for assortative mating. Next we grew assortatively mated offspring in daylengths representing seasonal variation and found the probability and timing of flowering changed across daylengths, with consistent direction and magnitude of traits correlations. [ABSTRACT FROM AUTHOR]

Information about a gene sometimes can be deduced by examining the impact of its mutation on phenotype. However, the genome-scale utility of the method is limited because, for nearly all model organisms, the majority of mutations result in little or no observable phenotypic impact. The cause of this is often attributed to robustness or redundancy within the genome, but that is only one plausible hypothesis. We examined a standard set of phenotypic traits, and applied statistical methods commonly used in the study of natural variants to an engineered mutant strain collection representing disruptions in 180 of the 192 ABC transporters within the bacterium Myxococcus xanthus. These strains display continuous variation in their phenotypic distributions, with a small number of "outlier" strains at both phenotypic extremes, and the majority within a confidence interval about the mean that always includes wild type. Correlation analysis reveals substantial pleiotropy, indicating that the traits do not represent independent variables. The traits measured in this study co-cluster with expression profiles, thereby demonstrating that these changes in phenotype correspond to changes at the molecular level, and therefore can be indirectly connected to changes in the genome. However, the continuous distributions, the pleiotropy, and the placement of wild type always within the confidence interval all indicate that this standard set of M. xanthus phenotypic assays is measuring a narrow range of partially overlapping traits that do not directly reflect fitness. This is likely a significant cause of the observed small phenotypic impact from mutation, and is unrelated to robustness and redundancy. [ABSTRACT FROM AUTHOR]

Species with extensive ranges experience highly variable environments with respect to temperature, light and soil moisture. Synchronizing the transition from vegetative to floral growth is important to employ favorable conditions for reproduction. Optimal timing of this transition might be different for semelparous annual plants and iteroparous perennial plants., We studied variation in the critical photoperiod necessary for floral induction and the requirement for a period of cold-chilling (vernalization) in 46 populations of annuals and perennials in the Mimulus guttatus species complex. We then examined critical photoperiod and vernalization QTLs in growth chambers using F2 progeny from annual and perennial parents that differed in their requirements for flowering., We identify extensive variation in critical photoperiod, with most annual populations requiring substantially shorter day lengths to initiate flowering than perennial populations. We discover a novel type of vernalization requirement in perennial populations that is contingent on plants experiencing short days first. QTL analyses identify two large-effect QTLs which influence critical photoperiod. In two separate vernalization experiments we discover each set of crosses contain different large-effect QTLs for vernalization., Mimulus guttatus harbors extensive variation in critical photoperiod and vernalization that may be a consequence of local adaptation. [ABSTRACT FROM AUTHOR]

Background and Aims: Seed dispersal impacts plant fitness by shaping the habitat and distribution of offspring, influencing population dynamics and spatial genetic diversity. Whether the evolution of dispersal strategies varies across herbaceous life forms (annual, perennial, clonal) is inconclusive. This study examines how seed dispersal strategies vary between annual and perennial populations of Mimulus guttatus (syn. Erythranthe guttata), investigating differences in seedpod orientation and shape, and the probability and distance of seed dispersal., Methods: We conducted a greenhouse experiment using 190 plants from 6 populations of annual and perennial M. guttatus, to compare floral orientation, seedpod architecture, and its effect on seed dispersal. We used controlled wind trials to measure the probability of seed dispersal and the dispersal distance of individual seeds from plants., Key Results: We identify three key differences in seedpod architecture and seed dispersal in annuals and perennials: seedpods are angled more upward-facing in perennials compared to annuals; a lower proportion of seed is dispersed in perennials; and seed disperse farther in perennials than annuals. These results are consistent with our predictions that a clonal, perennial life form should be associated with traits that increase the retention of seeds, requiring greater wind speeds to dislodge seed and increasing dispersal distance., Conclusions: Despite the close genetic relationship between annual and perennial populations of M. guttatus, we find differences in seedpod architecture and seed dispersal. We suggest that perennial plants, characterized by clonal reproduction and multi-year survival, benefit from strategies that facilitate long-distance seed dispersal to mitigate competition and promote colonization of new habitats., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)