DOI: 10.5061/dryad.qz612jmb8
title: Patterns of pollen dispersal and mating in a population of the clonal plant Sagittaria latifolia

description: 1) Increased plant size is generally expected to have negative
 consequences for mating by increasing pollen transfer between flowers of
 the same plant. Such geitonogamous self-pollination would then reduce
 sexual fitness through both female and male function. However, recent
 theoretical work has indicated that when plants grow clonally, the outward
 expansion of plants caused by clonal growth might have positive effects on
 siring without substantially increasing rates of self-pollination. 2) We
 investigated patterns of pollen dispersal, selfing, and siring in a
 monoecious population of the clonal plant Sagittaria latifolia, in which
 clones varied in size and the extent of intermingling with other clones. A
 spatially-explicit statistical model based on the inferred
 pollen-dispersal kernel was constructed to examine the mechanisms
 underlying observed mating patterns. 3) Pollen dispersal typically
 occurred over distances that exceeded the spatial extent of clones. There
 was a positive association between clone size (measured as the number of
 ramets per genet) and the likelihood that clones were intermingled with
 the shoots of other clones. Together, these patterns of pollen dispersal
 and clonal intermingling resulted in a weak positive association between
 clone size and selfing rates and a strong positive association between
 clone size and outcross siring success. These patterns were replicated in
 the spatially-explicit model, indicating that the intermingling of clones
 is an important determinant of mating patterns in this population. 4)
 Synthesis. Our study provides the first examination of the pollen
 dispersal kernel for a clonal plant. It is the first study providing
 empirical support for model predictions that potentially negative effects
 of increased selfing in large clones might be offset by increased siring
 success. This implies that the negative consequences of becoming large do
 not necessarily apply to clonal plants.
description: Details of the methods are provided in the associated
 publication, its supporting information, and the Rmd files accompanying
 the data. Briefly, phenological data, leaf tissue, and seeds were
 collected from 506 shoots in an isolated, natural population of the clonal
 emergent aquatic plant <em>Sagittaria latifolia</em>. Shoots
 were mapped using traingulation. Leaves and seeds were genotyped using
 seven SSR loci to enable mapping of the location of clones (genets) and
 the identification of sires. Interplant mating distances were used to
 infer the pollen-dispersal kernel (details of the methodology are given in
 Supporting Information Methods S1). Patterns of clonal intermingling were
 assessed using analysis of spatial data combined with inferred identities
 of genets (i.e., multi-locus lineages; details of the approach are given
 in Supporting Information Methods S2 and S3). Selfing rates were
 calculated for each shoot and then averaged across all shoots per genet
 using MLTR software (v. 3.4; Ritland, 2002). Paternity was inferred using
 Colony2 software (v. 2.0.6.5; Jones & Wang, 2010; Wang 2004,
 2018). Patterns of selfing and siring were analysed using linear models in
 R (v. 3.4.4; R Core Team; details provided in Supporting Information
 Methods S3).
description: The data were analysed using R and the three software programs
 listed in the Methods sections. Analyses of the data using R are
 replicated in the Supporting Information Methods S1, S2, and S3 and the
 code provided in the accompanying Rmd files.