Seed characteristics and germination limitations in the highly invasive Fallopia japonica s.l. (Polygonaceae)
Engler J, Abt K & Buhk C (2011): Seed characteristics and germination limitations in the highly invasive Fallopia japonica s.l. (Polygonaceae). Ecological Research 26: 555-562. IF 1.565, Q3
The species in the Japanese knotweed complex (Fallopia japonica s.l. and its hybrids) are among the most invasive plants on earth. In our study we examined the germination success of Fallopia japonica s.l. seeds of different ages, quality, and storage conditions. Irrespective of age and even after natural overwintering in the soil, seeds germinated well. The ungerminated seeds we collected in autumn 2008 were characterized by low weight/length ratio, low nutrient concentrations, and a greenish tepal coloration. Spring collected seeds were subject to strong predation by birds. The high germination observed under laboratory conditions, seed germination or early establishment in the field was inhibited and only a few seedlings were observed. In our paper we evaluated the clear risk that sexual reproduction could gain importance in the future as a result of changing environmental conditions or genetic adaptation. This would facilitate expansive dispersal by wind, as well as having the potential to increase further adaptation of the species complex.
