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Studies Of Verticillium Wilt And Characterization Of Candidate Verticillium Wilt Resistance Genes In The Mint Species Mentha Longifolia (L) Huds, Kelly Jean Vining

Doctoral Dissertations

To investigate the genetic basis of verticillium wilt resistance in mint (Mentha L., Lamiaceae), wild-collected germplasm obtained from the United States Department of Agriculture was employed to develop breeding populations for wilt resistance screening and molecular genetic study, including cloning of candidate verticillium wilt resistance genes.

A collection of fourteen Mentha longifolia accessions from Europe, Asia and South Africa was analyzed for morphological traits, oil composition, and verticillium wilt resistance. In addition, a preliminary molecular diversity assessment was conducted utilizing randomly amplified polymorphic DNA (RAPD) markers. The accessions were found to be diverse regarding all observed traits and the South …

A Survey For Sex Determination Systems In East African Lake Malawi Cichlids, Jennifer R. Ser

Master's Theses and Capstones

African cichlids are at an early stage in the evolution of sex chromosomes. Their sex chromosomes have not become distinct from the rest of their autosomal chromosomes, and no morphologically distinct sex chromosomes have been identified (Kornfield, 1984). These fishes therefore provide a unique model for understanding the early stages of sex chromosome evolution. It is further speculated that evolution of sex chromosomes may have an effect on cichlid speciation as well.

Lake Malawi formed in East African ∼700,000 years ago and contains a diverse flock of endemic cichlid fish (Danley at al., 2001). Within this flock the genus Metriaclima …

Gaca Regulation Of Luminescence In The Symbiotic Bacterium Vibrio Fischeri, Alicia Eve Ballok

Master's Theses and Capstones

The symbiosis of Euprymna scolopes and Vibrio fischeri depends on the ability of the bacterium to colonize the squid and produce light. GacA is an activator of symbiosis phenotypes including luminescence though it is not understood how GacA functions. My hypothesis, based on other bacterial models, is that GacA activates expression of CsrBs, functional RNAs, which sequester and repress a translational repressor, CsrA. I approached this question with mutagenesis and complementation techniques. We found mutation of CsrA or addition of a CsrB in trans could complement the GacA mutant for symbiosis and luminescence phenotypes. The inability of other luminescence regulators …

Sexual Compatibility And Seed Germination In Nolana Species, Amy C. Douglas

Master's Theses and Capstones

Nolana L.f. is a large, diverse genus in the Solanaceae endemic to coastal deserts of Peru and Chile. Large showy flowers and drought tolerance give Nolana great potential for breeding and cultivar development for the ornamental plant industry. As a precursor to breeding efforts, studies of floral development, sexual compatibility, and seed germination were conducted involving eight Nolana species (N. adansonii, K aticoana, N. elegans, N. humijusa, N. ivaniana, N. laxa, N. plicata, N. rupicola) cultivated at UNH.

Stigma receptivity and pollen viability were evaluated at a range of stages of flower development. Floral development keys were developed to provide …