COMING SOON! PQDT Open is getting a new home!

ProQuest Open Access Dissertations & Theses will remain freely available as part of a new and enhanced search experience at

Questions? Please refer to this FAQ.

Dissertation/Thesis Abstract

Screening for Allelopathic Potential and Self Facilitation in Japanese Hops (Humulus japonicus, Cannabaceae)
by Clark, Jonathan, M.S., Southern Illinois University at Edwardsville, 2015, 53; 10014413
Abstract (Summary)

Japanese hops (Humulus japonicus) is an introduced species from eastern Asia whose current distribution extends over most of the eastern U.S.A. H. japonicus is capable of rapid growth and can form dense blankets of foliage. It's been observed that native species fare poorly in the presence of H. japonicus. A set of experiments were designed to test for the potential of H. japonicus to produce chemicals that may inhibit germination and growth in its competitors. A standard laboratory germination assay was preformed using extracts from foliar material of H. japonicus testing for inhibition in germination of 3 target species—Festuca rubra, Raphanus sativus, and Lactuca sativa. A field experiment using soils from areas colonized with H. japonicus and adjacent areas where hops was absent was preformed looking for and effect on germination and growth in silver maple (Acer saccharinum). Lastly a laboratory assay was designed using extracts obtained from soils, colonized with H. japonicus and without, investigating the potential for H. japonicus to promote its own germination. The results of the germination assay showed a consistent and significant delay in germination in all target species treated with H. japonicus foliar extract vs. controls. The field trial showed a significant delay in germination in A. saccharinum as well. Humulus japonicus also proved to promote its own germination in soils occupied by H. japonicus vs. controls. These results support the idea that H. japonicus may use allelopathic chemicals to delay or inhibit germination in native competitors while promoting its own success.

Indexing (document details)
Advisor: Schulz, Kurt
Commitee: Barry, Kelly, McCraken, Vance
School: Southern Illinois University at Edwardsville
Department: Biological Sciences
School Location: United States -- Illinois
Source: MAI 55/03M(E), Masters Abstracts International
Subjects: Biology, Plant sciences
Keywords: Allelopathy, Humulus japonicus, Invasive, Self facilitation
Publication Number: 10014413
ISBN: 978-1-339-48474-7
Copyright © 2021 ProQuest LLC. All rights reserved. Terms and Conditions Privacy Policy Cookie Policy