The present study aims to establish the application of fluorescence spectroscopy as a field method in the determination of varietal differences after lettuce harvesting in greenhouse cultivation. The experimental studies were conducted on-site at the farm where the lettuce leaf accessions were grown. The fluorescence analysis was carried out with a source with an emission wavelength of 285 nm and an author-developed mobile fiber-optic experimental set-up. The subjects of this research are leaves from Djentelina, Hercules, Lolo Roca, and Paris White.

The correlation between the emission signals of the samples was established. This fact allows mobile fluorescence spectroscopy to be successfully applied as a rapid tool to establish the origin of unknown lettuce accessions in the presence of a rich library of spectra as an applied tool in breeding programs. The results of the experiment can be used to optimize the time for the analysis of the varietal differences of the lettuce genotypes after harvest in greenhouse cultivation. Fluorescence spectroscopy in a fiber-optical configuration will support the process of determining the belonging of a specific variety of lettuce to a given variety of lettuce (even for samples of unknown origin when it is necessary to qualify the result of accessions in a short time).