Intra- and interspecific pollen morphology variation of invasive Reynoutria taxa (Polygonaceae) in their response to different habitat conditions

By

Wiatrowska, Blanka
Dylewski, Łukasz
Bzdęga, Katarzyna
Tokarska-Guzik, Barbara
Dajdok, Zygmunt
Gobber, Agata
Wrońska-Pilarek, Dorota

Type

Article

Date of Publication

2025

Original Publication

Journal of Hymenoptera research

Volume

98

Pages

61--92

Subjects

Fallopia , Habitats , Invasive plant species , Pollen morphology , pollen variability , Reynoutria , SEM

Contributed by

Pensoft Publishers

Language

English

Published by

Washington, D.C International Society of Hymenopterists

Identifiers

DOI: https://doi.org/10.3897/neobiota.98.138657

 

Abstract

Although understanding the relationship between the reproductive mode and mass-dispersal potential of plants is crucial for studying invasion phenomena, the morphological features of invasive species’ pollen are not well understood. This study examined the pollen morphology and variability of three Reynoutria (knotweed) taxa (R. japonica, R. sachalinensis, R. × bohemica) invasive in Europe, and their reaction to different habitat conditions within seven distinguished habitat types. The pollen was sourced from 95 sites from the taxa’s invasive range in Central Europe. In total, 2850 pollen grains were measured and analysed for 11 quantitative and qualitative features. The pollen of R. sachalinensis was distinguished from that of the other two taxa (reticulate perforate) based on its rugulate and fossulate perforate exine ornamentation. The pollen’s response to various habitat conditions, which was most marked in R. × bohemica, was reflected by pollen size and exine thickness. Our research indicates that pollen availability is not a limiting factor for the sexual reproduction of knotweeds in Central Europe, including Reynoutria japonica, long considered male sterile. The observed presence of male-fertile specimens of R. japonica may enhance the efficiency of generative reproduction in this species throughout its invaded ranges. This finding should be considered when planning actions to control the population of these transformer plant species.