Smooth cordgrass (Spartina alterniflora Loisel) and sugarcane (Saccharum spp. hybrids) are both grasses that belong to the family Poaceae and have significant impact on Louisiana environment and economy. Coastal Louisiana accounts to ~80% of the national wetland loss through natural and human interventions; (re)vegetation is considered an important component of coastal restoration efforts. Smooth cordgrass, a warm season marsh grass, is used as an ecosystem engineer to stabilize and restore Louisiana coastal marshes. In this study, genetic diversity was determined among 13 elite smooth cordgrass accessions of Louisiana through 276 polymorphic markers generated by 23 SSR and 32 RAPD primers. AMOVA results showed that sufficient variation existed among smooth cordgrass accessions for further exploitation in breeding program. A few genetic markers unique to specific smooth cordgrass accession(s) were also developed. Sugarcane, the number one row crop in Louisiana, is sensitive to cold; so cold tolerance is desirable to expand its cultivation in more northern environments. Cold tolerance alleles of Saccharum spontaneum can be exploited to develop sugarcane clones tolerant to low temperatures. To this end, forty differentially expressed genes (DEGs; 29 up-regulated and 11 down-regulated) were identified in a cold-tolerant clone Ho02-144 and a cold-sensitive clone L79-1002 under cold stress, using annealing control primer system. Reverse-transcription PCR (RT-PCR) analysis of the cold-responsive DEGs revealed distinctive expression profiles in the tolerant and sensitive clone. Mining of the cold-responsive DEGs yielded 12 sequences with simple sequence repeats (SSRs), which were used to design eSSR primers. Genotyping of 48 Louisiana sugarcane clones and 16 ancestral parents with these eSSRs generated 170 polymorphic markers that could classify cultivated sugarcane clones from their ancestral S. spontaneum clones at 0.23 similarity coefficient. The cold responsive genes will be useful for breeding cold tolerant sugarcane either through genetic engineering or selection through the use of gene-based markers.
| Identifer | oai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-04262012-234223 |
| Date | 27 April 2012 |
| Creators | Bernaola Alvarado, Lina |
| Contributors | Kimbeng, Collins, Harrison, Stephen, Baisakh, Niranjan, Knott, Carrie |
| Publisher | LSU |
| Source Sets | Louisiana State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lsu.edu/docs/available/etd-04262012-234223/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached herein a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to LSU or its agents the non-exclusive license to archive and make accessible, under the conditions specified below and in appropriate University policies, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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