Seed size variation and predation of seeds produced by wild and crop-wild sunflowers.

@article{Alexander2001SeedSV,
  title={Seed size variation and predation of seeds produced by wild and crop-wild sunflowers.},
  author={Helen M. Alexander and Charity L. Cummings and Lewis Kahn and Allison A. Snow},
  journal={American journal of botany},
  year={2001},
  volume={88 4},
  pages={
          623-7
        }
}
The movement of pollen between crop and wild sunflowers (both Helianthus annuus) has led to concerns about the possible introduction of crop transgenes into wild populations. The persistence of crop traits in wild populations will depend in part on the relative fitness of crop-wild hybrid vs. wild plants. Using seeds from two large experimental field plots, we found that seeds produced by crop-wild plants were twice the size of wild seeds and differed in coloration. Head diameter, date of… Expand
Population ecology of wild sunflowers: effects of seed density and post-dispersal vertebrate seed predators
TLDR
Although initial seed density and vertebrate post-dispersal seed predation do appear to have effects on seedling recruitment, neither appear to be limiting seed production of competing adult plants, and variation in seed densities (over the range examined) may have limited effects on local population dynamics. Expand
Increased germination of diverse crop-wild hybrid sunflower seeds.
  • K. Mercer, R. Shaw, D. Wyse
  • Biology, Medicine
  • Ecological applications : a publication of the Ecological Society of America
  • 2006
TLDR
Investigation of how seed germination and dormancy were affected by sunflower crop wild hybridization found differences in relative germination of wild and hybrid seed indicated that the effect of germination on introgression will likely vary by population due, in part, to initial levels of dormancy in the population. Expand
Ecological patterns and genetic analysis of post‐dispersal seed predation in sunflower (Helianthus annuus) crop‐wild hybrids
TLDR
It is suggested that oil content may be a more important determinant of seed predation than seed size and molecular genetic evidence for this relationship is provided. Expand
Maternal effects and embryo genetics: germination and dormancy of crop–wild sunflower hybrids
Abstract Gene flow between agricultural crops and related wild plant populations can produce hybrids which differ significantly from their wild counterparts in many life history traits, includingExpand
Fecundity selection in a sunflower crop-wild study: can ecological data predict crop allele changes?
TLDR
The results suggest that ecological data can be useful for estimating the frequencies of crop genes following episodes of crop-wild hybridization in sunflowers and can be applied to other study systems in which data on survivorship and fecundity are used to estimate a genotype's evolutionary fitness. Expand
The mechanisms and consequences of seed bank formation in wild sunflowers (Helianthus annuus)
TLDR
The results suggest increased seed production of individual sunflowers resulting from crop transgenes would be unlikely to increase population growth on the scale of small patches, and the positive effects of increased seed bank size on population growth were tempered by density-dependence. Expand
Can achene selection in sunflower crop–wild hybrids by pre-dispersal seed predators hasten the return to phenotypically wild sunflowers?
TLDR
Results indicate that selection exerted by birds could result in the rapid evolution of crop–wild sunflower populations, whereas the plants without any selection were intermediate between the parents. Expand
EFFECTS OF COMPETITION ON THE FITNESS OF WILD AND CROP-WILD HYBRID SUNFLOWER FROM A DIVERSITY OF WILD POPULATIONS AND CROP LINES
TLDR
This research is the first study of its kind to demonstrate that the consequences of crop-wild gene flow are context dependent and contingent on the genetics of the specific wild populations and the local biotic and abiotic conditions. Expand
EFFECTS OF COMPETITION ON THE FITNESS OF WILD AND CROP‐WILD HYBRID SUNFLOWER FROM A DIVERSITY OF WILD POPULATIONS AND CROP LINES
Abstract Gene flow between crop fields and wild populations often results in hybrids with reduced fitness compared to their wild counterparts due to characteristics imparted by the crop genome. ButExpand
Role of soil seed banks and newly dispersed seeds in population dynamics of the annual sunflower, Helianthus annuus
TLDR
The role of the seed bank in population dynamics of the summer annual Helianthus annuus was explored and seed survival under field conditions was determined, and reproductive output was asymptotically related to the number of seedlings initially present. Expand
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