Allelopathic potential of Alliaria petiolata (Garlic Mustard) on germination of Lepidium sativum seeds

Diplomsko delo obravnava temo alelopatskega učinkovanja križnice navadna česnovka (Alliaria petiolata) na kalitev semen vrtne kreše (Lepidium sativum). Navadna česnovka (Alliaria petiolata) naj bi bila potencialno alelopatska in čedalje bolj invazivna, zato nas je zanimalo, kaj omogoča invazivni česnovki, da se uspešno naseli v tujih območjih in da se uspešno spopada s tamkajšnjimi avtohtonimi vrstami, čeprav v svojem avtohtonem okolju ni posebej dominantna. Ker večina avtorjev upošteva možnost, da naj bi bila česnovka potencialno alelopatska, smo s pomočjo bioloških testov poskušali prikazati vsebnost potencialno alelopatskih snovi v česnovki. Opazovali smo učinke vodotopnih ekstraktov (različnih koncentracij), učinke ekstraktov iz vzorcev tal in učinke hlapljivih snovi, sproščenih iz rastlinskih tkiv navadne česnovke na kalitev semen vrtne kreše (Lepidium sativum). Zanimala nas je kalivost in pojavitev sejancev ter dolžina kalice in korenin vrtne kreše. Zbrane podatke smo obdelali s pomočjo Studentovega t-testa v programskem orodju Statistica (Statsoft). Iz dobljenih rezultatov lahko razberemo, da imajo vodotopni ekstrakti iz listov močnejši zaviralni učinek na rast in kalitev kalic kot vodotopni ekstrakti iz korenin ter da se dolžina celotne kalice ter dolžina korenine vrtne kreše, prav tako pa tudi odstotek kalitve semen z naraščanjem koncentracije vodotopnih ekstraktov manjša. Odstotek kalivosti semen vrtne kreše v poskusih s hlapljivimi substancami je nižji v primerjavi s kontrolnimi poskusi.The diploma thesis discusses the allelopathic potential of Brassicaceae Alliaria petiolata to seeds of Lepidium sativum germination. Alliaria petiolata is supposed to be allelopathic and increasingly more invasive. Therefore, we were interested what enables the invasive Alliaria to populate foreign areas successfully and to fight with the autochthonous species successfully even though it is not especially dominant in its own environment. Because most of the authors consider a possibility that Alliaria is supposed to be allelopathic, we tried to show content of potential allelopathic substances in Alliaria with a help of biological tests. We observed the effects of water-soluble extracts (different concentrations), the effects of extracts of the soil nearby Alliaria petiolata and the effects of extracts with volatile substances of plant tissues\u27 extracts of Alliaria petiolata on Lepidium sativum seeds germination. We were interested in germination and appearance of seedlings and the length of radicle and roots. We examined the gathered data with Student t-test with software tools Statistica (Statsoft). We can discern from the gathered data that water-soluble extracts from leaves have stronger braking effect on growth and radicle germination than water-soluble extracts from roots and that the length of the whole radicle and the length of the Lepidium sativum root as well as the percentage of seeds germination with concentration of water-soluble extracts growth decrease. The percentage of Lepidium sativum seeds germination in experiments with volatile substances is lower in comparison to test experiments