A study on exudates and micromorphology of Primula
The genus Primula L. comprises more than 400 species, grouped in 6 subgenera and 37 sections . Especially the production of oily or farinose exudates on aerial surfaces of leaves, stems, calyces and flowers is a conspicuous character of this genus. These exudates consist primarily of un-substituted flavones and other flavones with unusual substitution patterns, which are probably derived from a still unidentified biogenetic pathway . Exudate profiles were monitored by HPLC and TLC, and known structures were identified by comparison of their UV-spectra and retention times with those of reference compounds of our spectral library. New structures were elucidated additionally by NMR spectroscopy. The auto-fluorescent property of some of these flavonoids was used for studying their accumulation in glandular hairs in vivo by using an epifluorescence microscope. Different colors of fluorescence were observed within a single leaf of P. vulgaris Huds., while leaves of P. vialii Delavay ex Franch. showed uniform fluorescence. The significance of our findings in relation to chemodiversity, morphology, and micromorphological character differentiation will be discussed.
Acknowledgement: Hochschuljubiläumsstiftung der Stadt Wien, Gesellschaft zur Förderung der Pflanzenwissenschaften.
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