UNLABELLED BACKGROUND AND AIMS High-temperature environments with >30 degrees C during flowering reduce boll retention and yield in cotton. Therefore, identification of cotton cultivars with high-temperature tolerance would be beneficial in both current and future climates. * METHODS Response to temperature (10-45 degrees C at 5 degrees C intervals) of pollen germination and pollen tube gr...

In honeybee colonies there normally is a queen that lays eggs and workers that supply food and maintain the nest. However, worker bees are able to reproduce in the absence of the queen. A variety of factors, including temperature, food, pheromones and social interactions, have an influence on ovarian development. Protein-rich diets are known to promote ovarian and egg development and, since the...

Lifetime seed production can be constrained by shortfalls of pollen receipt ('pollen limitation'). The ovule oversupply hypothesis states that, in response to unpredictable pollen availability, plants evolve to produce more ovules than they expect to be fertilized, and that this results in pollen limitation of seed production. Here, we present a cartoon model and a model of optimal plant reprod...

The establishment of pollen-pistil compatibility is strictly regulated by factors derived from both male and female reproductive structures. Highly diverse small cysteine-rich proteins (CRPs) have been found to play multiple roles in plant reproduction, including the earliest stages of the pollen-stigma interaction. Secreted CRPs found in the pollen coat of members of the Brassicaceae, the poll...

Although prehistoric native peoples probably used wild rice for food and ceremony, evidence is sparse. Macrofossil remains of wild rice are uncommon on archaeological sites even where the plant is still common nearby. The association between documented human habitation and wild rice is explored with pollen records from associated wild rice wetlands. For this, reliable identification of wild ric...

During 2 months of the pollen season, the acute and putative adjuvant effect of traffic-related air pollution on respiratory health was investigated in children sensitised to grass pollen or house dust mite (HDM). Respiratory complaints were objectified via measurement of exhaled NO and inflammatory mediators in nasal lavage (NAL). During the study children, skin prick negative (n = 31) or posi...

Pollen hydration is usually tightly regulated and occurs in vivo only when desiccated pollen grains acquire water from the female, thus enabling pollen tube growth. Pollen tubes are easily visualized by staining with decolorized aniline blue, a stain specific for callose. We identified a mutant, raring-to-go, in which pollen grains stained for callose before anther dehiscence. When raring-to-go...

The relationship between pollen germination and the dynamic organization of the actin cytoskeleton during pollen germination is a central theme in plant reproductive biology research. Maize (Zea mays) pollen grains were implanted with 30 keV argon ion (Ar(+)) beams at doses ranging from 0.78 x 10(15) to 13 x 10(15) ions/cm(2). The effects of low-energy ion implantation on pollen germination via...

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...

Competition among pollen grains for the chance to fertilize ovules typically involves two stages: arrival times on stigmas and/or the growth of pollen tubes through styles. In a previous study of Hibiscus moscheutos, we found that individual pollen donors often differed in pollen tube competitive ability. Here we determined whether short delays in pollen arrival time altered the average success...