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Thesis (M.S.)--Miami University, 2007. / Title from first page of PDF document. Includes bibliographical references (p. 38-43). Also available online via OhioLINK's ETD Center: http://rave.ohiolink.edu/etdc/view?acc%5Fnum=miami1193256414.

Thesis (M.S.)--Miami University, Dept. of Botany, 2007. / Title from first page of PDF document. Includes bibliographical references (p. 38-43).

This dissertation explores Fanny Fern's literary position and her role as a social critic of American lives and attitudes in the nineteenth-century. A reexamination of Fern's literary and non-literary works sheds light on her firm stand for the betterment of all mankind. The diversity and multiplicity of Fern's social criticism and her social reform attitudes, evident in Ruth Hall. Rose Clark, and in voluminous newspaper articles, not only prove her concern for society's well-being, but also reflect her development of and commitment to her writing career.

The life cycle of land plants alternates between the haploid gametophyte and the diploid sporophyte generations. Asexual reproductive strategies, that bypass meiosis and fertilization, have evolved in diverse land plant taxa. Apogamy is one such strategy that produces a sporophyte directly from a gametophyte cell. The genes that drive the process of apogamy are unknown. Knowledge of these genes and their functions will provide insight into the evolution of asexual reproduction, the sporophyte body plan and the alternation of generations in land plants. My Ph. D. research has focused on identifying the genes function in apogamy commitment, and understanding the functions of their counterparts in angiosperms. First, I successfully induced apogamy from the fern Ceratopteris richardii and discovered that the gametophytes begin to become committed to apogamy after 10 days of culture on inductive medium. I then created a cDNA library that represents genes with enhanced expression during commitment. Comparison of the Gene Ontology terms mapped to this cDNA library with that of the gametophyte transcriptome of the fern Pteridium aquilinum showed that this library is enriched in genes that function in stress response and metabolism. This library contains many sequences whose homologues in Arabidopsis are specifically expressed or upregulated in flower organs or seed structures, both of which are absent in ferns. One of these genes, UNC93-like, is expressed in the eggs of C. richardii gametophytes, as evidenced by in situ hybridization. Functional egg cells are implicated as necessary for C. richardii gametophytes to undergo apogamy. In Arabidopsis, an AtUNC93-like mutant, which produces a partial AtUNC93-like transcript, has vegetative and reproductive defects. Embryo abortion and gametophyte lethality contribute to a small seed set in these plants. Reciprocal crosses indicate that the mutant allele does not affect gametophyte function but cause a maternal failure to maintain viability of all gametophytes. Thus, the AtUNC93-like gene is necessary for normal sporophyte vegetative growth and reproductive success, but is dispensable for the direct function of gametophytes. My research has provided insight into the mechanisms that induce apogamy in a fern. The apogamy library is a valuable resource for future investigations into apogamy.

Spores from a weakly salt tolerant strain of Ceratopteris richardii containing the mutation stl1 were irradiated and sown on nutrient medium supplemented with 200 m M NaCl. A single highly salt tolerant gametophyte was recovered and selfed to generate a homozygous sporophyte. Spores from this strain, 10α23, were used to document the sexual transmission of the trait and to monitor the inheritance of tolerance in crosses to both the wild type and to the parental salt tolerant strain. Genetic analysis showed the 10α23 strain to possess both the original stl1 mutation and an additional semi-dominant nuclear mutation, stl2, that individually conferred a high level of tolerance to gametophytes. In combination, both mutations had additive effects. Tolerance was also evident in sporophytes, but at a lower level than in gametophytes.

Mutant strains of the fern Ceratopteris richardii Brongn. were selected in vitro for tolerance to culture medium containing Al2(SO4)3-Na2EDTA at pH 4.4. Three strains, HαAT3, HαAT7, and HαAT29 showed enhanced growth relative to the wild type on selection medium. Because of the complex nature of the selection conditions, the mutants were tested for tolerance to low pH and other individual components of the selection medium. All three mutant strains were notably more tolerant to acidic conditions and slightly more tolerant to Na2EDTA, relative to the wild type. No consistent differences in response to Na2SO4 were evident. Genetic characterization indicated a single nuclear gene basis of inheritance for strain HαAT3. Strains HαAT7 and HαAT29 showed a nuclear basis of tolerance, but responses of gametophytes from F1 hybrids suggested segregation at two or more loci.

A dissertation submitted to the faculty of science university of the Witwatersrand, Johannesburg for the Degree of Master of Science Johannesburg 1992 / The gametophyte generation of the fern life cycle is initiated with the formation of spores. The spores of C. viridis (Fonsic) Swarts var. glaeca (Sim) schelp Anthony are trilete and have a cristate spore wall ornamentation. Under favourable conditions the spores of C. viridis var. glauca show polar germination [Abbreviated Abstract. Open document to view full version] / GR2017

Plants contain organelles called chloroplasts, which is where photosynthesis takes place. Chloroplasts also contain their own DNA, which is separate from the DNA in the nucleus. This DNA does not change much over evolutionary time, so it can be used to investigate relationships between organisms. Here we created a tool that makes it easier to analyze this chloroplast DNA as well making it easier to share complete chloroplast genomes on public databases. In addition, we also found a mobile element in the chloroplast DNA of a group of ferns, which appears to be driving structural changes in their genomes.