Can heterosis and inbreeding depression explain the maintenance of outcrossing in a cleistogamous perennial?

<p>What maintains mixed mating is an evolutionary enigma. Cleistogamy, wherein a single plant produces both flowers capable of outcrossing (chasmogamous) and obligately selfing (cleistogamous), offers an ideal model to examine selfing costs. The evolution towards greater self-fertilization within populations could be restrained by inbreeding depression, whereas heterosis in crosses between populations could strengthen the inclination towards outcrossing. While empirical assessments of inbreeding depression and heterosis within the same cleistogamous system remain scarce, our research contributes by examining the potential disadvantages of self-fertilization, quantifying inbreeding depression and heterosis across three populations of the cleistogamous perennial, Ruellia humilis. The dataset found here contains the raw data for individual fitness components (number of seeds, germination, reproduction and number of flowers) that were used to estimate inbreeding depression and heterosis. </p>