In: Phyton 57 (2017): S. 47-57 DOI: 10.12905/0380.phyton57-2018-0047 Published online on 12th February 2018

Published online on 12th February 2018

Phytotoxic effects of Fallopia japonica and F. ×bohemica leaves

Jasna Dolenc Koce & Katarina Šoln

Key words: Fallopia japonica, Fallopia ×bohemica, leaf extract, phytotoxicity, germination, growth.

Summary
Dolenc Koce J. & Šoln K. 2018. Phytotoxic effects of Fallopia japonica and F. ×bohemica leaves. – Phyton (Horn, Austria) 57 (1–2): 47–57, with 3 figures.

Japanese and Bohemian knotweed (Fallopia japonica, F. ×bohemica) are among the most invasive species in Europe and they can substantially reduce native biodiversity. In the present study, the phytotoxic potential of their leaves was tested. First, aqueous extracts of 0.5 % and 5 % (w/v) were prepared and used for watering seeds and seedlings of two test species: radish (Raphanus sativus) and maize (Zea mays). Germination and growth were monitored for 7 days (short-term treatment). Second, test plants grew in soil with ground Fallopia leaves for a few weeks (long-term treatment). Seed ger­mination was not affected, but the subsequent early growth of the seedlings was reduced mainly due to inhibited root growth. In seedlings treated with knotweed extracts, biochemical markers related to oxidative stress showed diverse changes; catalase activity mainly decreased, lipid peroxidation and total antioxidative capacity increased, while guai­acol peroxidase responded non-specifically. When seedlings were treated with ground Fallopia leaves in the soil over a few weeks their growth was not affected (roots) or was even stimulated (taproots, leaves). The age of Fallopia leaves (young, mature, old) used for preparation of extracts had no significant effects on growth of treated seedlings. Japanese and Bo­hemian knotweed leaves showed moderate potential for phytotoxic activity.