DOI: 10.5061/dryad.8779
title: Data from: Isolation barriers between Petunia axillaris and Petunia integrifolia (Solanaceae)

description: The isolation barriers restricting gene flow between populations or
 species are of crucial interest for understanding how biological species
 arise and how they are maintained. Few studies have examined the entire
 range of possible isolation barriers from geographic isolation to next
 generation hybrid viability. Here we present a detailed analysis of
 isolation barriers between two flowering plant species of the genus
 Petunia (Solanaceae). Petunia integrifolia and P. axillaris feature
 divergent pollination syndromes but can produce fertile hybrids when
 crossed in the laboratory. Both Petunia species are primarily isolated in
 space but appear not to hybridize in sympatry. Our experiments demonstrate
 that pollinator isolation is very high but not strong enough to explain
 the absence of hybrids in nature. However, pollinator isolation in
 conjunction with male gametic isolation (i.e. pollen-pistil interaction)
 can explain the lack of natural hybridization, while postzygotic isolation
 barriers are low or non-existent. Our study supports the notion that
 reproductive isolation in flowering plants is mainly caused by pre- rather
 than postzygotic isolation mechanisms.
description: Fig1ABFig1AB.xls provides the
 raw data used in the figure 1, A and B. A: These data were obtained in
 Puerto Viejo (location 1), Uruguay and describe the weight (in g) of the
 P. integrifolia capsules obtained after having covered the flowers either
 during the day or night. B: These data were obtained in Rivera (location
 2), Uruguay and describe the weight (in g) of the P. integrifolia capsules
 obtained after having covered the flowers either during the day or
 night.Fig2ABFig2AB.xls provides the
 raw data used in figure 2 A and B.Data are presented into three sheets
 which show redundancy: Pax vs Pin: data obtained when germinated and
 ungerminated pollen grains either from P. axillaris or P. integrifolia
 were counted. Pax vs Phy: data obtained when germinated and ungerminated
 pollen grains either from P. axillaris or F1 hybrids were counted. Pin vs
 Phy: data obtained when germinated and ungerminated pollen grains either
 from P. integrifolia or F1 hybrids were counted.Fig2CDEFig2CDE.xls provides the raw data used in figure 2 C, D and E. Data are presented into two excel sheets: "data" with the raw source data, and "Length" with the length of pollen tubes calculated. In the "data" sheet, each cross is named after the following rules: Pax is a P. axillaris plant of a given number Pin is a P. integrifolia plant of a given number Ph is a F1 hybrid plant of a given number The plant that stand before the "x" is always the female (seed parent) and the one after the "x" is the male (pollen donour). The name is then followed by the date of the pollination (dd mm yy).Fig3BFig3B.xls provides the raw data used in Figure 3 B. Data are presented into two excel sheets: "P.axillaris" and "Hybrids". All data were obtained either in Minas, Uruguay, or in Rivera, Uruguay.These data sheets show the number of visitations of "small bees", "big bees", "diurnal butterflies" and hawkmoths on P. axillaris and F1 hybrids during day (8h-12h) and night (21h-23h) periods. Behaviours are devided into "Approaches", "Landings" and "Feedings".Fig 1CDFig1CD.xls provides the raw data used in the figure 1, C and D. C: These data were obtained in José Ignacio (location 1), Uruguay and describe the weight (in g) of the P. axillaris capsules obtained after having covered the flowers either during the night or that were not covered (control). The replications that were covered during the day were lost due to mowing by farmers. D: These data were obtained in Carmelo (location 2), Uruguay and describe the weight (in g) of the P. axillaris capsules obtained after having covered the flowers either during the day or night, or not covered at all (control).Fig 3AFig 3A.xls provides the raw data used in Figure 3 A. Data are presented into three excel sheets: "PintegrifoliaPuertoViejo", "hybridsPuerto Viejo" and "NightPuerto Viejo". All data were obtained in Puerto Viejo, Uruguay. These data sheets show the number of visitations of "small bees", "big bees", "butterflies" and other insects on P. integrifolia and F1 hybrids in Puerto Viejo.Fig 4ABFig 4AB.xls provides the raw data used in Figure 4 A and B.Data are presented into three excel sheets: "Capsules formation rate PV" and "Size & Weight PV" for Puerto Viejo experiment only, and "Minas" for the part of the experiment that took place in Minas, Uruguay. The number of capsules formed and number of marks found is shown. Then, the percentage of capsule formed is calculated.