Submitted to: HortScience
Publication Type: Abstract Only
Publication Acceptance Date: 7/20/2004
Publication Date: 7/20/2004
Citation: Tisserat, B., Vaughn, S.F. 2004. Influence of physical parameters on the growth, morphogenesis, and volatile monoterpene production in Mentha spicata L. cultures in vitro. Hortscience. 39(4):778-779.
Technical Abstract: The influence of altering the physical environments on the growth (fresh weight), morphogenesis (leave, root, and shoot numbers), and secondary metabolism (i.e., volatile monoterpene, C10, carvone) on Mentha spicata L. (spearmint) shoots cultured on Murashige and Skoog medium without growth regulators was studied. The type of physical support (e.g., agar, liquid, platforms, or glass supports) employed with Magenta vessels greatly influenced culture growth and morphogenesis. Mint shootlets grown on liquid medium only produced 4-x fold more fresh weight than shootlets grown on agar medium. Carvone levels were unaffected by any of the tested physical support treatments. Increasing the frequency of culture media replacement within Magenta vessels significantly increased growth and morphogenesis without altering carvone levels. The influence of vessel size on spearmint shoots was tested by culturing shoots on a variety of culture vessels including culture tubes, Magenta GA-7 containers, and one-half gallon jars. Positive correlations occurred between culture vessel capacity and their growth, morphogenesis, and carvone levels. A comparative study was conducted testing growth, morphogenesis, and secondary metabolism occurring from several spearmint cultivars grown either in culture tubes or in an automated plant culture system (APCS, a sterile hydroponics system). The APCS allowed for the production of greater biomass (e.g., ~15-x fold increase in fresh weight), morphogenesis, and secondary metabolism to occur compared to that obtained within culture tubes. Carvone was only produced from cultured spearmint shoots and was absent in either roots or callus cultures. Carvone levels decreased proportionally in spearmint shoots as the distance from the shoot terminus increased for plantlets grown in either the culture tubes or the APCS. The number of media culture immersions (4, 8, 12, or 16 immersions/day) employing the APCS greatly effected growth, morphogenesis, and secondary metabolism. Twelve immersions of media/day were optimum for growth and morphogenesis compared to 4, 8, or 16 immersions/day. Generally, higher culture growth rates resulted in lower carvone levels per treatment; however, overall carvone levels/vessel increased due to greater biomass production occurring per vessel.