Date of Award
Bachelor of Science Honours
Faculty of Communications, Health and Science
Dr Jacqueline Rummey
Dr Ian Bennett
The search for the chemical or set of chemicals that act as a germination stimulant in Lactuca sativa v. Grand rapids (a variety of lettuce seed) was the underlying basis of this project. Through the development of a solid phase extraction (SPE) system different fractions of smoky water were tested for their effects on germination enhancement. The project targeted streamlining the amount of solvents as well as time used in past research on smoky water. Previously, several steps involving high perfo1mance liquid chromatography (HPLC), thin layer chromatography (TLC) and Gas Chromatography (GC) were employed. This project used SPE cartridges to separate fractions and isolate components. Cartridges of the non-polar varieties were C18, C8, Phenyl and Cyanopropyl. After cartridge loading with smoky water and flushing, three fractions of increasing concentration of methanol from a buffered ethanoic acid/methanol system were created. These fractions were extracted into hexane before application to bioassays. Polar cartridges were also loaded with smoky water and fractionated with mixtures of hexane, and increasing concentrations of dichloromethane and methanol. These four fractions were not extracted but applied directly to bioassays. Fraction activity was prevalent in early eluting fractions from non-polar cartridges but the pattern was more varied from the polar cartridges. Solutions not retained by cartridges enhanced germination except for solutions from 20H and Amino cartridges. GC fractions from the three C18 fractions highlighted differences in peak number and comparative peak ratios within chromatograms. This emphasised that component separation was resulting from the SPE system. An adsorption test on seed coats of L. sativa was unable to reject the hypothesis that germination enhancing components do adsorb irreversibly to the seed coat. An application of l, 8 -cineole as a result of a poor Mass Spectrometry (MS) library match proved to be a source of germination enhancement at low concentrations.
Adriansz, T. D. (1998). A solid phase extraction system for the isolation of the germination cue in smoky water when subjected to the light sensitive lettuce Lactuca Sativa v. Grand Rapids. https://ro.ecu.edu.au/theses_hons/749