Preferred Name

T. Warner Lowry III

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Date of Graduation

Spring 2019

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Department of Biology

Advisor(s)

Michael Renfroe

Conley K. McMullen

Heather Griscom

Abstract

The in vitro propagation is a promising method for the production of plants in species that are endangered, commercially valuable, and/or otherwise difficult to propagate through traditional horticultural methods. Leaf and petiole explants of critically endangered African violets (Saintpaulia rupicola B.L. Burtt) were cultured on a chemically defined medium that was supplemented with six different concentrations of thidiazuron (TDZ). The concentrations were used for either an induction medium on which the explants remained throughout development, or an induction medium on which the explants remained for 10 days followed by a basal growth medium for the remainder of the 12 weeks. None of the petiole explants grew or developed any organs. Leaf explants from all treatments developed callus from which adventitious shoots differentiated. Initially leaf explants with 5 µM TDZ preformed significantly better than all treatments apart from 8 µM TDZ. Upon further experimentation, TDZ concentrations lower than 5 µM had no significant difference from the 5µM TDZ. Callus isolated from leaf explants was placed on a basal medium and subsequently formed adventitious shoots. Isolated shoots were able to grow in size and develop further when planted on a basal medium or directly on soil. Isolated shoot tips were also encapsulated in sodium alginate to form synthetic seeds, or synseeds. Experiments were performed to determine if 2% or 3% sodium alginate was better for the emergence of the isolated shoots. Experiments were then performed with 2% sodium alginate synseeds with four concentrations of plant preservative mixtureTM (PPMTM). There was no significant difference between the PPMTM treatments so the largest concentration, 5.0 ml/L, was used for remaining experiments. Finally, experiments were performed with 0.0 ml/L and 5.0 ml/L PPMTM included in the matrix of synseeds planted on sterile vermiculite, non-sterile vermiculite, and non-sterile soil. Synseeds planted on non-sterile soil had significantly less plant growth than all other media treatments. All experiments with synseeds had shoots emerge that then rooted and grew into new plants. The methods presented in this thesis are useful in the mass production of new S. rupicola plants for the purposes of conservation both ex situ and in situ.

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