The influence of agronomic parameters on the density and length of leaf stomata in purpure coneflower (Echinacea purpurea (L.) Moench) / Vpliv agronomskih parametrov na gostoto in dolžino listnih rež pri ameriškem slamniku (Echinacea purpurea (L.) Moench)
Authors: Kolar Darja , Virant Igor , Kreft Samo 
Published: January 2019

IzvlečekPripravki ameriškega slamnika (Echinacea purpurea) se zaradi svojih imunostimulativnih učinkov zelo pogosto uporabljajo predvsem pri prehladih in gripi. Uporaba in popularnost teh pripravkov je v zadnjih letih zelo narasla, kar dokazujejo tudi vedno večja ponudba na trgu. Številne raziskave so bile narejene na področju gojenja, kvantifikaciji aktivnih učinkovin, učinkovitosti in varnosti. Ugotavljali smo, kakšna je gostota listnih rež na zgornji in spodnji strani listov ter merili dolžino listnih rež na spodnji strani listov ameriškega slamnika pri 213 vzorcih. Vzorci so se razlikovali po načinu gojenja rastlin. Gostote in dolžine rež smo merili z mikroskopiranjem odtisov epiderme, ki smo jih naredili s prozornim lakom. Preverili smo vpliv velikosti lista in vpliv pozicije na listu, kjer smo izvajali meritve. Ugotovili smo, da se gostote in dolžine listnih rež med lokacijami po širini lista značilno razlikujejo. Zato smo v nadaljevanju poskusa merili reže na določenem mestu na sredini med osrednjo žilo in listnim robom. Najbolj izrazit in signifikanten vpliv na lastnosti listnih rež ima sezona žetve. Pri jesenski žetvi v primerjavi s poletno je bila gostota rež zgornje strani listov 66 % večja (p<0,001), dolžina rež spodnje strani pa 11 % večja (p<0,001). Pri proučevanju vplivov agronomskih dejavnikov (namakanje, starost rastlin, lokacija njive) nismo našli signifikantnih vplivov na lastnosti listnih rež. Opazili smo tudi signifikantno negativno korelacijo med gostoto in dolžino rež ter pozitivno korelacijo med gostoto rež spodnje in zgornje strani lista. Večje rastline so imele daljše listne reže in manjšo gostoto listnih rež v primerjavi z manjšimi rastlinami. Ta vpliv je bil statistično signifikanten, vendar majhen. Rastline z večjim odstotkom suhe mase v požeti biomasi (manjša vsebnost vode) so imele večjo gostoto rež in manjšo dolžino listnih rež, vendar so povezave signifikantne le pri poletni žetvi. Med koncentracijami cikorne in kaftarne kisline in gostoto ter dolžino listnih rež ni signifikantnih korelacij. Ključne besede: listne reže, Echinacea purpurea, ameriški slamnik AbstractHerbal preparations from Echinacea purpurea (purple coneflower) are often used in common cold and flu because of their immune stimulatory effects. The popularity of these products has grown considerably in recent years, and there is increasing market supply. Numerous studies have been made investigating the cultivation, quantification of active ingredients, safety and efficacy of Echinacea purpurea. In this study we determined the density of the leaf stomata on the lower and upper sides of the leaves and the length of the leaf stomata on the lower side of leafs in 213 samples of E. purpurea plants, which differed in the cultivation parameters. Density and length were measured with the microscopic examination of the imprint of the epidermis, which we made with clear nail varnish. We checked the effect of the size of the leaf and the influence of the measuring position on the leaf. We found that the densities and the length of the stomata were significantly different across the width of the leaf. Therefore, we carried out measurements at a constant position in the middle between the central vein and the leaf edge. The most pronounced parameter influencing the stomata properties was season of harvesting. In the autumn harvest compared to summer, the density of the stomata of the upper side was 66% higher (p <0.001) and the stomata length on the lower side was 11% higher (p <0.001). We did not find significant effects of any of the studied agronomical parameters (irrigation, age of plants and location of plantation) on the properties of leaf stomata. We also observed a significant negative correlation between the stomata density and stomata length and a positive correlation between the stomata density of the lower on the upper side of the leaf. We observed that larger plants had longer stomata and lower stomata density compared to smaller plants. This effect was statistically significant but small. Plants with a higher percentage of dry mass in harvested biomass (lower water content) had a higher stomata density and smaller stomata lengths, but the correlation was significant only in summer harvest. There are no significant correlations between chicoric and caftaric acids concentrations and the stomata density or length. Key words: leaf stomata, Echinacea purpurea, purple coneflower