Identifier

etd-11152013-134645

Degree

Master of Science (MS)

Department

Plant, Environmental Management and Soil Sciences

Document Type

Thesis

Abstract

Sea oats (Uniola paniculata L.) is a perennial grass commonly used to help build and stabilize dunes in coastal restoration projects along the northern Gulf of Mexico. In Louisiana most sea oats plants transplanted to the beach as part of these projects are genetically identical. This lack of diversity can be extremely detrimental to the success of these large-scale sea oats communities because the susceptibility of one plant to a stressor is shared by all sea oats plants of the same genotype. Two main methods to reverse this lack of diversity are via plant breeding and the production of vegetative material from seed. Therefore the first two goals pertained to furthering research related to these methods. Production of sea oats from seed is encumbered by a few problems, one of which is low germination attributed to seed dormancy and/or pathogens which reside within seed, on seed surface or in immediate soil zone. The first study of this thesis assessed the impact of four commercial fungicides each at two rates on the production of sea oats seedlings from seed. The fungicide treatments azoxystrobin at 1x rate and thiophanate-methyl at 1x and 2x rates were found to increase sea oats germination and survival, as well as seedling quality. A high quality seedling was based on seedlings’ shoot height, root length and fresh weight after 8 weeks of growth. The second study aimed to improve efficiency of sea oats breeding for coastal use. Due to the considerable number of years required for breeding relative to the rapid rate of coastal erosion, a reduction of time and expenses required for researchers to travel to coastal breeding and selection nurseries could increase efficiency. This reduction could be met by relocating selection nurseries to urban locations closer to researchers potentially leading to swifter releases of varieties. The second study conducted preliminary research into the possibility of relocation by assessing whether the average performances of selected populations, unselected populations and varieties of sea oats differed when produced outside of the coastal zone. Results found that unselected populations had higher means than selected populations for plant height, stem count, number of tillers, vigor and stem density. It was also found that means of varieties were lower than means of unselected populations for most variables and almost always similar to selected populations. Using previous data of height, stem count and vigor of varieties at a beach location, it was found that varieties had lower means at the urban location than coastal. This would suggest that the performance of varieties differed at the two locations and because the performances differed of these populations and varieties; that selection studies of sea oats for coastal use should likely not occur in urban inland conditions such as those in Baton Rouge, LA, U.S. However, this study does suggest that selection for urban use of sea oats in this location could be successfully conducted. Due to the growing sector of native ornamental grasses in the southeastern U.S. in addition to previous displays and studies of ornamental traits of some sea oats lines, breeding and selection research should be conducted in order to produce exciting, original and lucrative ornamental sea oats varieties. The third and final study of this thesis assessed 312 sea oats experimental lines for ideal ornamental qualities such as reddish purple foliage, leaf width and plant form as well as strong growth performance in urban conditions. Fifty experimental lines were selected for advancement into further breeding and selection stages as part of the process of developing potential landscape varieties.

Date

2013

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Labonte, Don

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