Dispersal by Animals
Seeds carried to
Seeds buried in caches
Seeds in feces
Many angiosperm species reproduce both asexually and sexually.
Sexual reproduction results in offspring that are genetically different from their parents.
Asexual reproduction results in a clone of genetically identical organisms.
Fragmentation, separation of a parent plant into parts that develop into whole plants, is a very common type of asexual reproduction.
In some species, a parent plantís root system gives rise to adventitious shoots that become separate shoot systems.
Apomixis is the asexual production of seeds from a diploid cell.
Advantages and Disadvantages of Asexual Versus Sexual Reproduction
Asexual reproduction is also called vegetative reproduction.
Asexual reproduction can be beneficial to a successful plant in a stable environment.
However, a clone of plants is vulnerable to local extinction if there is an environmental change.
Sexual reproduction generates genetic variation that makes evolutionary adaptation possible.
However, only a fraction of seedlings survive.
Many angiosperms have mechanisms that make it difficult or impossible for a flower to self-fertilize.
Dioecious species have staminate and carpellate flowers on separate plants.
Some floral adaptations that prevent self-fertilization
Sagittaria latifolia staminate flower (left) and carpellate flower (right)
(b) Oxalis alpina flowers
Floral Adaptations that prevent self-fertilization: stamens and styles mature at different times or are arranged to prevent self pollination / self fertilization.
Oxalis alpina flowers
The most common is self-incompatibility, a plantís ability to reject its own pollen.
Researchers are unraveling the molecular mechanisms involved in self-incompatibility.