Alelopatsko djelovanje ekstrakta listova običnog oraha i nekih invazivnih biljnih vrsta na klijanje pšenice (Triticum aestivum L.) i gorušice (Sinapis alba L.)

Abstract

Termin alelopatija odnosi se na pozitivan ili negativan, izravan ili neizravan učinak jedne biljke na drugu stvaranjem kemikalija koje se ispuštaju u okoliš. Polazna je hipoteza da invazivne biljke povećavaju vlastitu uspješnost na novom području izlučivanjem (alelo)kemikalija koje izravno ili neizravno inhibiraju rast okolnih biljaka. Kako bih provjerila tu hipotezu, pripremila sam ekstrakte listova negundovca, pajasena, čivitnjače, običnog oraha, japanskog pridvornika i mirisavog bagrema u tri različite koncentracije. Njima sam jedan dan natapala sjeme pšenice i bijele gorušice, a zatim to sjeme prenijela u Petrijeve posudice i navlažila istim ekstraktima. U većini slučajeva ekstrakti listova inhibirali su klijanje i rast testnih biljaka, a inhibicijsko djelovanje povećavalo se s porastom koncentracije ekstrakata. Klijanje i rast testnih biljaka najjače su inhibirali ekstrakti listova bagrema. U svrhu pouzdanijih zaključaka o alelopatskom djelovanju neke invazivne vrste potrebno je ispitivanja provesti u uvjetima što bližima onima u prirodi, koristeći samonikle biljne vrste kao testne organizme.The term allelopathy refers to positive or negative, direct or indirect effect of one plant on another through the production of chemicals that are emitted into the environment. The initial hypothesis is that invasive plants increase their own success in new environment by exuding (allelo)chemicals which directly or indirectly inhibit the growth of neighbouring plants. To check that hypothesis I made extracts of leaves of boxelder maple, tree of heaven, false indigo-bush, common walnut, japanese knotweed and black locust in three different concentrations. I soaked wheat and white mustard seeds in these extracts for one day after which I transferred those seeds into Petri dishes and wetted them with the same extracts. In most cases the extracts of leaves inhibited the germination and growth of the tested plants and the inhibitory effects increased proportionally with the concentration of extracts. The germination and growth of the tested plants were most inhibited by the extracts of leaves of black locust. In order to get more certain conclusions about the allelopathic effects of an invasive species, it is necessary to conduct the experiment in the conditions most similar to those in nature, using wild plant species as test organisms