Production dynamics of the allelochemical parthenin in leaves of Parthenium hysterophorus L.

Publication Type

Journal contribution

Authors

Reinhardt, C. and Van der Laan, M. and Belz, R. G. and Hurle, K. and Foxcroft, L.

Year of publication

2006

Published in

Weed Biology and Weed Control

Editor

Gerhards, R. and Belz, R.G.

Pubisher

Eugen Ulmer KG , Stuttgart-Hohenheim, Germany

Band/Volume

Special Issue XX/

Series/labeling

Journal of Plant Diseases and Protection

ISBN / ISSN / eISSN

1861-4051

Page (from - to)

427-433

Conference name

24th German Conference on Weed Biology and Weed Control

Conference location

Stuttgart-Hohenheim, Germany

Conference date

March 4-6

Parthenium hysterophorus L. is regarded as a noxious alien invader in many parts of the world, including southern Africa. There are indications that the invasiveness of the plant may be partly connected with allelopathy, mainly based upon the sesquiterpene lactone parthenin. The aim of the present study was to track parthenin levels in leaves over the life cycle of the plant, in order to get an insight into the production dynamics of parthenin. Plants were grown in a greenhouse from seeds originally taken from a population in Kruger National Park, South Africa. Leaves were sampled at various growth stages over the life cycle and were chemically analysed for parthenin levels. Parthenin levels in leaves sampled at 12 different growth stages were determined through HPLC analysis. Results showed that the parthenin content of leaves increased with plant age, reaching a peak at the beginning of flowering. At senescence, the total number of leaves on a single plant yielded about 270 mg parthenin. Considering that P. hysterophorus usually builds up dense stands and other plant parts, notably flower parts and achenes, also contain appreciable amounts of parthenin, a considerable amount of this compound could be released from a P. hysterophorus population into the environment. Although parthenin is not the only allelochemical produced by P. hysterophorus, findings of this study confirm that it is a major constituent of the leaves of P. hysterophorus. At the high levels of parthenin produced, this phytotoxin could conceivably play a central role in shaping the invaded vegetation.