Pollen limitation is a key assumption of theories that explain mast seeding, which is common among wind-pollinated and woody plants. In particular, the pollen coupling hypothesis and pollination Moran effect hypothesis assume pollen limitation as a factor that synchronizes seed crops across individuals. The existence of pollen limitation has not, however, been unambiguously demonstrated in wind-pollinated, masting trees. We conducted a two-year pollen supplementation experiment on a masting oak species, Quercus lobata. Supplemental pollen increased acorn set in one year but not in the other, supporting the importance of pollen coupling and pollination Moran effect models of mast seeding. We also tracked the fate of female flowers over five years and found that the vast majority of flowers were aborted for reasons unrelated to pollination, even in the presence of excess pollen. Pollen limitation can reduce annual seed set in a wind-pollinated tree, but factors other than pollen limitation cause the majority of flower abortion.
Mate limitation in small populations can reduce reproductive fitness, hinder population growth, and increase extinction risk. Mate limitation is exacerbated in self-incompatible (SI) taxa, where shared S-alleles further restrict mating. Theory suggests genetic drift as a predictor of mate limitation and the breakdown of SI systems.
- Plant lipid transfer proteins (LTPs) are crucial for moving lipids between membranes, impacting pollen wall development, including the pollen aperture structure.
- The study focuses on a rice mutant called pollen aperture defect 1 (Ospad1), which shows male sterility due to abnormal pollen grain development linked to a non-specific LTP that fails to properly bind lipids.
- Researchers found that OsPAD1 interacts with a gene involved in pollen development, providing new insights into how LTPs function in forming pollen apertures, which could have broader implications for other cereal crops.
Background: Pollen is a crucial source of nutrients and energy for pollinators. It also provides a unique habitat and resource for microbiota. Previous research on the microbiome of pollen has largely focused on angiosperm systems, with limited research into coniferous gymnosperms.
Mutations in the CsEMS1 gene result in male sterility and reduced wart number and density. Male sterility and fruit wart formation are two significant agronomic characteristics in cucumber (Cucumis sativus), yet knowledge of our underlying genetics is limited. In this study, we identified an EMS-induced male sterility and few small warts mutant (msfsw).
State Key Laboratory of Extreme Photonics and Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027, China.
Measurement of masses of microscale objects or weak force with ultrahigh sensitivity (down to nanogram/piconewton level) and compact configuration is highly desired for fundamental research and applications in various disciplines. Here, by using freestanding gold flakes with high reflectivity (≈98% at 980 nm) as the sample tray and silica microfibers with extremely low spring constant (≈0.05 mN m) as the cantilever beams, miniature capacitive balances are reported with piconewton-level detection limit (picobalances) and reliable radiation force-based calibration.
