Browsing by Subject "asexual"
Results Per Page
Sort Options
Item Open Access Development of microsatellite markers for the apomictic triploid fern Myriopteris lindheimeri (Pteridaceae).(Applications in plant sciences, 2015-11-10) Grusz, AL; Pryer, KMPREMISE OF THE STUDY:Microsatellite markers were developed for investigating the population dynamics of Myriopteris lindheimeri (Pteridaceae), an apomictic triploid fern endemic to deserts of the southwestern United States and Mexico. METHODS AND RESULTS:Using 454 sequencing, 21 microsatellite markers were developed. Of these, 14 were polymorphic with up to five alleles per locus and eight markers amplified in one or more congeneric close relatives (M. covillei, M. fendleri, M. aurea, and M. rufa). To demonstrate marker utility, M. lindheimeri samples from three Arizona populations were genotyped at nine loci. For each population, diversity measures including percent polymorphic loci, frequency of heterozygotes across all loci, and genotypic diversity were calculated. Across the three populations, on average, 63% of loci were polymorphic, the average frequency of heterozygotes (across all loci) was 0.32, and average genotypic diversity was 0.34. CONCLUSIONS:These markers provide a foundation for future studies exploring polyploidy and apomixis in myriopterid ferns.Item Open Access Evolutionary Patterns and Processes in the Desert-Adapted Fern Genus Myriopteris (Pteridaceae)(2014) Grusz, Amanda LeeThis dissertation investigates the processes of hybridation, polyploidy, and apomixis and their roles in the evolution of myriopterid ferns. First, I examine patterns of hybridization in members of the Cheilanthes yavapensis complex using a suite of techiniques, ranging from molecules to morphology--including isozymes, spore measurements, and molecular phylogenetics based on chloroplast and nuclear DNA markers--to elucidate relationships in this notorious group of ferns. Second, I utilize the rules of traditional taxonomy set by the International Code of Botanical Nomenclature to recircucmscribe and resurrect the genus Myriopteris from within cheilanthoid ferns. This revised classification is bolstered by results from my molecular phylogenetic analysis of DNA sequence data in the subsequent chapter. Then, using morphological and cytological analyses, I examine the evolution of indument, leaf and rachis shape, vernation, chromosome number, and reproductive mode across the myriopterid tree. In my concluding chapter I develop microsatellite markers for the apomictic triploid, M. lindheiemeri, and explore whether premeiotic chromosome duplication facilitates the production of genetically distinct offspring in this otherwise asexual lineage.