Abstract Detail



Pteridology

Vu, Amanda [1], Grusz, Amanda [2].

Testing the gender response of apogamous ferns to exogenous antheridiogens: A case study in Myriopteris lindheimeri (Pteridaceae).

Antheridiogens are gibberellin-like pheromones that are produced by some ferns during their gametophytic life stage. These pheromones are known to trigger the development of male reproductive structures in nearby, late-germinating prothalli. Antheridiogen systems increase outcrossing in populations of otherwise bisexual, self-compatible homosporous gametophytes. Their effects have been widely documented across sexually reproducing homosporous ferns, which, in the absence of antheridiogens, generally produce hermaphroditic (i.e. bisexual) gametophytes. Despite being well-studied in sexually reproducing groups, the effect of antheridiogens on apomictic (asexual) fern gametophytes is unknown. This is surprising, given the frequent implication of sperm in the spread of heritable apomixis in ferns. Indeed, little is known regarding the extent of antheridium production in apomictic lineages, let alone the response (if any) of apomictic gametophytes to exogenous antheridiogen. In this study, we test the gametophytic response of an apomictic triploid (3x) fern, Myriopteris lindheimeri, to antheridiogens produced by Pteridium aquilinum (Apt). Onoclea sensibilis, a species with a strong Apt response, is used as a positive control. Spores were sterilized and sown at a standardized density on agar plates, in multiple replicates enriched with serial dilutions of Apt. After sowing, spores were germinated under a 12 hrs light – 12 hrs dark cycle in otherwise constant conditions, and were measured weekly. Staining was used to detect the presence of antheridia on gametophyte tissues. Gametophyte measurements and date of antheridium formation are compared among statistical replicates. Our findings represent a first step toward understanding the role, if any, of antheridiogens on gametophyte development and gender determination in apomictic ferns, and shed some light on the role of sperm production in the spread of heritable apomixis.


1 -
2 - University Of Minnesota Duluth, Biology, 1035 Kirby Drive, SSB 207, Duluth, MN, 55812, United States

Keywords:
apogamy
apomixis
autopolyploid
Gametophyte
Pteridophyte
reproductive mode.

Presentation Type: Poster
Number: PPT004
Abstract ID:611
Candidate for Awards:None


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