Weeds cause significant yield loss in sweetpotato. Post-emergent herbicides cause damage to sweetpotato plant, which necessitates development of herbicide tolerant sweetpotato. An optimal tissue culture system is a prerequisite for in vitro screening of herbicide tolerant sweetpotato. Three Louisiana cultivars, Beauregard, Orleans, and LA 07-146, were tested to develop an efficient callus induction and plant regeneration system. 2, 4-D @ 0.23 µM was ideal for Beauregard and Orleans callus induction and 0.45 µM 2, 4-D for callus induction in LA 07-146. Phytohormone-free media was found suitable for regeneration. Plants were regenerated from callus tissues that survived in vitro with 2 µM, 6 µM, 8 µM and 10 µM of halosulfuron methyl (active ingredient of herbicide Sandea®). The culture conditions identified through this study have applicability to wide use in somaclonal selection in sweetpotato.
Adventitious root emergence from original cuttings of sweetpotato marks the initial phase of storage root development. A better understanding of the mechanism of adventitious rooting in sweetpotato will be of immense importance to strategize breeding efforts to maximizing its marketable yield. In the present study, role of ethylene in adventitious rooting was investigated by application of 3.8 ppm of 1-mcp to two sweetpotato cultivars, Beauregard and Evangeline, known to have contrasting adventitious rooting in response to 1-mcp. Sequencing of suppression subtractive hybridization libraries from both cultivars indicated that genes involved in the cell wall and sugar biosynthesis pathway were differentially expressed by exogenous application of 1-mcp. Two component response regulator, fructose bisphosphate aldolase and arabinogalactan, were present in both cultivars. However, their expression pattern varied at different time points between Beauregard and Evangeline. Genes coding for ascorbate oxidase and oxysterol-binding protein were upregulated in Beauregard whereas two-component response regulator was upregulated in both Beauregard and Evangeline. Except for a slight upregulation of fructose-bisphosphate aldolase in Beauregard and arabinogalactan in Evangeline at 12 h time point, both genes showed downregulation in both cultivars at all other time points. Most of the differentially expressed genes were shown to be involved in ethylene signaling. This study confirmed previous results that ethylene is involved in adventitious rooting in sweetpotato.
| Identifer | oai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-05202014-114042 |
| Date | 09 June 2014 |
| Creators | Polozola, Michael |
| Contributors | Baisakh, Niranjan, Labonte, Don, Johnson, Charles, Villordon, Arthur |
| 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-05202014-114042/ |
| 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. |
Page generated in 0.0018 seconds