DOI: 10.5061/dryad.qs4nh
title: Data from: Divergence in pollen performance between Clarkia sister species with contrasting mating systems supports predictions of sexual selection

description: Animal taxa that differ in the intensity of sperm competition often differ
 in sperm production or swimming speed, arguably due to sexual selection on
 postcopulatory male traits affecting siring success. In plants, closely
 related self- and cross-pollinated taxa similarly differ in the
 opportunity for sexual selection among male gametophytes after
 pollination, so traits such as the proportion of pollen on the stigma that
 rapidly enters the style and mean pollen tube growth rate (PTGR) are
 predicted to diverge between them. To date, no studies have tested this
 prediction in multiple plant populations under uniform conditions. We
 tested for differences in pollen performance in greenhouse-raised
 populations of two Clarkia sister species: the predominantly outcrossing
 C. unguiculata and the facultatively self-pollinating C. exilis. Within
 populations of each taxon, groups of individuals were reciprocally
 pollinated (n = 1153 pollinations) and their styles examined four hours
 later. We tested for the effects of species, population, pollen type (self
 vs. outcross), the number of competing pollen grains, and temperature on
 pollen performance. Clarkia unguiculata exhibited higher mean PTGR than C.
 exilis; pollen type had no effect on performance in either taxon. The
 difference between these species in PTGR is consistent with predictions of
 sexual selection theory.
description: Observations on
 individual styles (n=1153 records)Each record in this
 spreadsheet includes the observations recorded for an individual style,
 including whether it was self- vs. cross-pollinated, the number of pollen
 grains adhering to the stigma, and the number of pollen tubes visible in
 each 1-mm interval of the style four hours following pollination. The
 temperature recorded at the time of pollination and the mean temperature
 recorded for the four hours following pollination are also included. The
 stigma penetrance rate and the mean pollen tube growth rate among all
 pollen tubes visible in the style are also estimated based on Equation 1
 in the published manuscript.IndividualStyles_N_of_1153.xlsPollen Donor Means by Pollination Type (Selfed vs Outcrossed Pollinations) (N=254)Each of the 254 records in this spreadsheet includes the mean values for the observations recorded for the selfed or the outcrossed flowers of a given pollen donor. In a very few cases, a pollen donor is represented by only one type of pollination. This data set was used in all of the analyses reported in the published article and in the Supplemental Materials for which the sample size was ~254 (in some analyses, the sample size was reduced due to missing values).PollenDonorMeansByPollinationType_SelfedVsOutcrossed_N_of_254.xlsPollen Donor Means (Means of Selfed and Outcrossed Pollinations) (N=136)Each of the 136 records in this spreadsheet includes the mean values for the observations recorded for the selfed AND the outcrossed flowers of a given pollen donor. In other words, these values are the means of the two means (i.e., the mean of the selfed flowers and the mean of the outcrossed flowers). This data set was used in all of the analyses in the Supplemental Materials for which the sample size was ~136 (in some analyses, the sample size was reduced due to missing values).PollenDonorMeans_MeanOfSelfedAndOutcrossed_N_of_136.xls