Date of Award:

8-2012

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Plants, Soils, and Climate

Advisor/Chair:

Dr. Paul G. Johnson

Abstract

Fine-leaved Festuca valesiaca possesses abiotic stress tolerances. However, their agronomic performances in the western United States and its genetic relationship to species of the Festuca ovina complex have not been investigated. Also, natural hybridization due to open pollination presents difficulties in distinguishing them for closely related taxa using morphological analysis. Given the species’ agronomic potentials, a project was designed to identify Festuca valesiaca accessions possessing high biomass production and seed yield for possible low-maintenance applications and to examine their relatedness to taxa of the Festuca ovina complex by multi-locus AFLP genotyping and chloroplast DNA sequence analysis using primer combinations designed from three intergenic spacers.

Plant vigor, height and width, total biomass, and seed weight and seed number of Festuca valesiaca accessions were evaluated from 2009 to 2011 at Blue Creek, Utah in a random complete block design with six replications. The Festuca valesiaca accessions examined produced abundance of small seeds. Seed production was significantly (P = 0.001) correlated (r2 = 0.84) with the total biomass, plant height, and plant vigor rating. The Festuca valesiaca accessions examined possessed lower height than the control ‘Cascade’ but higher biomass, spring green-up, and seed production. Given their morphological attributes, Festuca valesiaca accessions PI 659923, W6 30575, and W6 30588 should be considered for low-maintenance applications and use in plant improvement.

The AFLP-based neighbor-joining analysis indicated that Festuca valesiaca is a closely related subcluster of Festuca ovina and should be considered as one species. Festuca trachyphylla is a subcluster under Festuca ovina and Festuca valesiaca. Festuca idahoensis has a close relationship with Festuca roemeri but not with Festuca ovina. Low admixture was detected between the Festuca rubra and Festuca trachyphylla accessions examined, while a comparative high admixture was detected among the commercial cultivars examined.

Chloroplast sequences data reconfirmed that the Festuca ovina complex genetically differed from Festuca rubra and the other reference taxa examined. Festuca valesiaca and Festuca ovina possessed the same maternal lineage based on chloroplast DNA sequence analysis. One Festuca valesiaca accession, W6 30537, was genetically similar to the Festuca rubra examined and should be putatively reclassified as Festuca rubra pending further taxonomic analysis.

Comments

This work made publicly available electronically on October 19, 2012.

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