ibclogo XVI International Botanical Congess


Abstract Number: 3789
Poster No. = 1192


BRYOPHYTE SEX RATIOS


N. McLetchie,L. Stark & B. Mishler, Univ of KY Lexington KY 40506,Univ of NV Las Vegas NV 89154 & Univ of CA Berkeley CA 94720


Many bryophyte populations have female-biased adult sex ratios. Higher sexual reproductive costs before fertilization in males relative to females may contribute to this bias. Using an epiphyllous liverwort, Diplasiolejeunea pellucida, we tested the predictions that survival, growth and asexual reproduction favor females not producing sexual offspring compared to males and successful females. For 3 yr. we followed ca. 1,500 plants to estimate survival and growth, and examined ca. 1,000 specimens, noting the occurrence of asexual reproduction. Trends in survival and growth were in the predicted direction and significant between the two types of females. Asexual reproduction was not as predicted: unsuccessful females had lower asexual reproduction than males and successful females. These results are compared with observations on a desert moss, Syntrichia caninervis.


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