The Potential for Mixed Mating in a Self‐Incompatible Plant

A previous study showed that flowers of Campanula rapunculoides (Campanulaceae) are strongly self‐incompatible when the stigma first becomes receptive but are less strongly self‐incompatible as the flowers age. We deposited equivalent loads of self and outcross pollen onto either 1‐d‐old or 4‐d‐old stigmas and examined seed paternity using the PGI (phospho‐gluco‐isomerase) genetic locus. Pollen mixtures (50:50) on young flowers yielded only outcross progeny, indicating functional self‐incompatibility. Pollinations on the older stigmas, however, resulted in progeny arrays that departed significantly (χ2 test, \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $$P< 0.001$$ \end{document} ) from the expectations from pure outcrosssing, with self‐fertilizations estimated at 15%–22%, depending on the cross. The ability to produce both selfed and outcrossed progeny, i.e., mixed mating, coupled with a 6% increase in fruiting success of C. rapunculoides flowers pollinated shortly before floral senescence may provide an opportunity for reproductive assurance in natural populations of this species.