Skip to main content
ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Invasive Species and Pollinator Health » Research » Publications at this Location » Publication #364527

Research Project: Watershed-scale Assessment of Pest Dynamics and Implications for Area-wide Management of Invasive Insects and Weeds

Location: Invasive Species and Pollinator Health

Title: Exploring the germination ecology of Iris pseudacorus populations invading California wetlands [abstract]

item GILLARD, MORGANE - University Of California, Davis
item CASTILLO, JESUS - University Of Seville
item MESGARAN, MOHSEN - University Of California, Davis
item Futrell, Caryn
item Grewell, Brenda

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/18/2019
Publication Date: 10/18/2019
Citation: Gillard, M., Castillo, J.M., Mesgaran, M.B., Futrell, C.J., Grewell, B.J. 2019. Exploring the germination ecology of Iris pseudacorus populations invading California wetlands [abstract]. Meeting Abstract. Abstract.

Interpretive Summary:

Technical Abstract: Seed germination is largely influenced by environmental factors, and an important step in the success of sexual reproduction of angiosperms. The dispersal and germination of sexual propagules can contribute to the invasiveness and spread of plant species. Therefore, having knowledge about the germination ecology of the species is of importance for improving management strategies. Recent finding showed that populations of Iris pseudacorus (yellow flag iris) invading freshwater wetlands in the northwestern US reproduce mostly through sexual reproduction and spread via buoyant seeds. However, existing literature about the germination requirement of this species is narrow, and extant information is largely from studies of populations from freshwater wetlands in the native European range. Thus, we evaluated the germination requirements of invasive seeds of I. pseudacorus coming from intertidal populations in Petri dishes placed in incubators under different conditions of stratification, light, and temperature. We also tested the impact of the presence or absence of seed coat on germination under greenhouse conditions. We found that stratification treatments are not essential for these populations to germinate, and that the seeds of I. pseudacorus can germinate without light. The germination velocity increased with temperatures. In addition, at constant temperatures, seeds germinated little below +24°C but they were able to germinate quite well up to 36°C. Nonetheless, experiencing alternating temperatures seems mandatory for this species to maximize its germination fraction. Finally, the presence or absence of the seed coat did not impact the germination fraction or germination velocity. This work allowed us to determine requirements necessary for seeds of I. pseudacorus to germinate. These findings will help managers to predict the germination potential of the existing populations, with the aim to control and prevent further spread of the species in California wetlands. Poster Presentation: California Invasive Plant Council (CAL IPC).