The Relationship between Pollen Load and Fruit Maturation and the Effect of Pollen Load on Offspring Vigor in Cucurbita pepo

DEVELOPMENTAL SELECTION IN RESPONSE TO ENVIRONMENTAL CONDITIONS OF THE MATERNAL PARENT IN MIMULUS GUTTATUS

“…Prezygotic selection as a result of pollen competition was evaluated by comparing light and heavy pollinations. The pollination intensity had a large effect on reproductive output and, as observed in other studies, a higher proportion ofseeds aborted following light pollinations (Stephenson, 1981;Winsor et al, 1987;Lee, 1988). However, there appeared to be very little indication that microgametophytic selection could account for the increase in tolerant progeny under copper supplemented conditions.…”

The Influence of Garden Size and Floral Cover on Pollen Deposition in Urban Community Gardens

“…This has the same effect of decreasing the conspecific pollen load, in that space becomes less available to conspecific pollen that could potentially fill the stigma, germinate, and fertilize ovules. High conspecific pollen loads, on the other hand, are more likely to initiate fruit production (Bertin 1990) and increase seed production and weight (Winsor et al 1987;Bertin 1990) in flowering plants.…”

Racing Pollen Tubes.

“…Most important, a number of studies have shown that when pollen load is high-that is, when pollen competition is intense-progeny sporophytes are often more fit than when there is no pollen competition. For a numberof cultivated plants, the offspring of pollen that engaged in competition show less phenotypic variation and germinate sooner, are larger, and flower earlier than plants from pollen that didn't compete (e.g., Winsor et al, 1987). Although these results seem to indicate that fast-growing pollen produce better offspring, Walsh and Charlesworth (1992) have pointed out that female flowers often respond to the presence of large quantities of pollen by increasing the resources they devote to offspring production.…”