In: Phyton 56, Fasc. 1 (2016): S. 49-59 DOI: 10.12905/0380.phyton56(1)2016-0049


Growth Stimulating Effects of Ailanthus altissima Root and Leaf Extractives on Radicle and Hypocotyl Growth of Garden Cress (Lepidium sativum) and a Possible Evidence for Growth Inhibiting Root Exudates

By

René Rehorska, Julia Jamnig, Jürgen Lernbeiss, Anton Drescher, Maria Müllerand Hartwig W. Pfeifhofer, with 4 Figures

Key words: Ailanthus altissima, Lepidium sativum, growth stimulation, al­lelopathy, phytotoxicity, ailanthone, quassinoids.

Summary
Rehorska R., Jamnig J., Lernbeiss J., DrescherA., MüllerM. & PfeifhoferH. W. 2016. Growth stimulating effects of Ailanthus altissima root and leaf extractives on radicle and hypocotyl growth of garden cress (Lepidium sativum) and a possible evidence for growth inhibiting root exudates. – Phyton (Horn, Austria) 56 (1): 49–59, with 4 figures.

Ailanthus altissima (Mill.) Swingle contains various compounds with strong phytotoxic effects on growth and germination of other plants. On the contrary in our previous work we observed that low concentrations of A. altissima leaf extrac­tives did show stimulating effects on radicle and hypocotyl growth of Lepidium sativum L. To prove this observation in an adequate way we performed a bioassay with L. sativum and are able to show that low concentrations of A. altissima leaf extractives indeed stimulate leaf and hypocotyl growth of L. sativum. Furthermore we introduce a simple hydroculture setup which we used to investigate probably existing mechanisms of phytotoxic root exudations that may offer A. altissima ad­vantages over neighboring plant species. Although the existence of such mecha­nisms seemed doubtful to us at the beginning, the results derived from this experi­ment suggest that A. altissima leachate did significantly inhibit radicle and hypoco­tyl growth of L. sativum.