Gametophytes in ferns differ from those in bryophytes primarily in their reproductive strategies, with ferns favoring outcrossing while bryophytes often self-fertilize.
Here's a more detailed comparison:
Reproductive Strategy:
- Ferns: The gametophytes of ferns tend to favor outcrossing (fertilization with a different individual). This is likely because ferns exhibit clonal growth and vegetative competition during their haploid stage, where only the gametophyte exists.
- Bryophytes: Bryophytes are more prone to haploid selfing (self-fertilization). This may be due to clonal growth and vegetative competition predominantly occurring in the diploid sporophyte stage, not the haploid gametophyte phase.
Key Differences Summarized:
| Feature | Fern Gametophytes | Bryophyte Gametophytes |
|---|---|---|
| Dominant Ploidy | Sporophyte (2n) | Gametophyte (n) |
| Preferred Reproduction | Outcrossing (sexual reproduction with another gametophyte) | Selfing (self-fertilization) |
| Clonal Growth/Competition | Haploid stage | Diploid stage |
In essence, the difference lies in where clonal growth and competition are most pronounced. In ferns, these processes occur during the haploid gametophyte stage, encouraging outcrossing for genetic diversity. In bryophytes, they are more prominent during the diploid sporophyte stage, leading to a higher incidence of selfing.
