The Ecology of Autogamy in Wild Blueberry (Vaccinium angustifolium Aiton): Does the Early Clone Get the Bee?

Abstract

Wild blueberry, Vaccinium angustifolium Aiton, for the most part requires cross-pollination. However, there is a continuum across a gradient from zero to 100% in self-compatibility. We previously found by sampling many fields that 20–25% of clones during bloom have high levels of self-compatibility (≥50%). In 2009–2011, and 2015 we studied the ecology of self-pollination in wild blueberry, specifically its phenology and bee recruitment and subsequent bee density on bloom. We found that highly self-compatible clones were predominantly early blooming genotypes in the wild blueberry population. On average, fruit set and berry weight were highest in self-compatible genotypes. The bumble bee community (queens only early in the spring) was characterized by bees that spent large amounts of time foraging in self-compatible plant patches that comprised only a small proportion of the blueberry field, the highest density in the beginning of bloom when most genotypes in bloom were self-compatible. As bloom proceeded in the spring, more plants were in bloom and thus more land area was occupied by blooming plants. The absolute density of bumble bee queens per m2 declined, as a dilution effect, and this probably resulted in lower fruit set throughout the field.

Parameterization and Calibration of Wild Blueberry Machine Learning Models to Predict Fruit-Set in the Northeast China Bog Blueberry Agroecosystem

“…In our research, the best machine learning model trained on the wild blueberry simulation dataset was regarded as the best representation of the relationships between fruit-set and the eight predictor variables by learning the basic pattern of pollination dynamics of multiple blueberry species. Although bog blueberry may have diverse genotypes (e.g., the proportion of self-compatible genotypes, [64]) that could cause different pollination dynamics, these differences can still be explained by a metamodel with re-parameterization on a small amount of bog blueberry data. The difference of decomposed feature-level variance before and after metamodel calibration (the visualizations in Figure 7) might shed light on this point.…”

Genotypic variation in blueberry flower morphology and nectar reward content affects pollinator attraction in a diverse breeding population

“…Morphological traits can also influence fruit set through the promotion of outcrossing, which is crucial for circumventing fruit abortion due to self-incompatibility or early-acting inbreeding depression (Rick and Dempsey, 1969; Levy et al, 1978; Krebs and Hancock, 1990). Blueberry flowers exhibit herkogamy, wherein the stigma’s location within the corolla and the distance between the stigma and anthers reduce the incidence of self-pollination (Drummond and Rowland, 2020; Bieniasz and Konieczny, 2022). In wild lowbush blueberry (V. angustifolium), style length and the exertion of the stigma beyond the corolla were positively correlated with berry weight and the number of seeds per berry (Sampson et al, 2013), suggesting these traits may be beneficial for pollinator attraction or pollination success.…”