AUTHOR=Gao Jingwen , Guan Bo , Ge Minjia , Eller Franziska , Yu Junbao , Wang Xuehong , Zuo Jincheng 

TITLE=Can allelopathy of Phragmites australis extracts aggravate the effects of salt stress on the seed germination of Suaeda salsa?

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.990541

DOI=10.3389/fpls.2022.990541

ISSN=1664-462X

ABSTRACT=<p><italic>Phragmites australis</italic> is highly adaptable with high competitive ability and is widely distributed in the coastal wetland of the Yellow River Delta. However, allelopathic effects of <italic>P. australis</italic> on the growth of neighboring plants, such as <italic>Suaeda salsa</italic>, are poorly understood. In this study, germination responses of <italic>S. salsa</italic> seeds collected from two different habitats (intertidal zone and inland brackish wetland) to the extracts from different part of <italic>P. australis</italic> were compared. Potential allelopathic effects on germination percentage, germination rate, radicle length, and seedling biomass were analyzed. The germination of <italic>S. salsa</italic> was effectively inhibited by <italic>P. australis</italic> extract. Extract organ, extract concentration, and salt concentration showed different effects, the inhibitory rates were highest with belowground extract of <italic>P. australis</italic> between the four different parts. Germination percentage and germination rate were significantly decreased by the interactive effect of salt stress and extract concentration in <italic>S. salsa</italic> from a brackish wetland but not in <italic>S. salsa</italic> from the intertidal zone. The impact of different extracts of <italic>P. australis</italic> on radicle length and seedling biomass of <italic>S. salsa</italic> showed significant but inconsistent variation. The response index results showed that the higher concentration of extract solution (50 g·L<sup>−1</sup>) of <italic>P. australis</italic> had stronger inhibitory effect on the seed germination and seedling growth of <italic>S. salsa</italic> while the belowground extract had the strongest negative effect. Our results indicated that allelopathy is an important ecological adaptation mechanism for <italic>P. australis</italic> to maintain a high interspecific competitive advantage in the species’ natural habitat.</p>